Skulls and Bones: A Guide to the Skeletal Structures and Behavior of North American Mammals

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Page iii Skulls and Bones A Guide to the Skeletal Structures and Behavior of North American Mammals Glenn Searfoss

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title: author: publisher: isbn10 | asin: print isbn13: ebook isbn13: language: subject publication date: lcc: ddc: subject:

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Page iv Copyright © 1995 by Stackpole Books Published by STACKPOLE BOOKS 5067 Ritter Road Mechanicsburg, PA 17055 All rights reserved, including the right to reproduce this book or portions thereof in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. All inquiries should be addressed to Stackpole Books, 5067 Ritter Road, Mechanicsburg, PA 17055. Printed in the United States of America 10 9 8 7 6 5 4 First edition Cover design by Kathleen Peters Illustrations by Glenn Searfoss Library of Congress Cataloging-in-Publication Data Searfoss, Glenn. Skulls and bones : a guide to the skeletal structures and behavior of North American mammals / Glenn Searfoss ; [illustrations by Glenn Searfoss].1st ed. p. cm. Includes bibliographical references (p. ) and index. ISBN 0-8117-2571-5 1. MammalsNorth AmericaIdentification. 2. BonesNorth America Identification. 3. SkeletonNorth AmericaIdentification. 4. BonesNorth AmericaCollection and preservation. I. Title. QL715.S43 1995 599'.04471'097dc20 94-26504 CIP < previous page

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Page v This book is dedicated to people of all ages who are interested in the study and collection of bones. May this book aid in your understanding of relationships between an animal's skeletal structures and its lifestyle. For beginning and experienced collectors, may it offer useful hints on physical safety, collecting techniques, and specimen preparation. < previous page

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Page vii Contents Acknowledgments

ix

Introduction

1

Chapter 1. Classification Systems

3

Chapter 2. The Skull

16

Chapter 3. Skulls Illustrated

50

Chapter 4. The Limbs

98

Chapter 5. The Vertebral Column and Ribs

157

Chapter 6. The Significance of Skeletal Structures

180

Chapter 7. Bone-Collecting Basics

202

Chapter 8. Bone Preparation and Cleaning

215

Glossary of Terms

227

Appendix A. Things to Do

237

Appendix B. Scientific Terms and Common Names

247

Appendix C. Scientific Classification

251

Appendix D. Suppliers

255

Appendix E. Societies and Associations

261

Recommended Reading

267

Index

273

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Page ix Acknowledgments There are many people who deserve recognition for their influence in the fashioning of this book. To this end, I would like to thank the following people and organizations. The editors and production staff at Stackpole Books who made this book possible. The Denver Museum of Natural History and the Jefferson County Nature Center, whose specimens from their osteology collections provided the models for illustrations presented in this book. Dr. Cheri Jones, Ph.D., Curator of Mammalogy at the Denver Museum of Natural History, whose expertise and insightful views aided the development of this work. The 1993 sixth-grade science classes and their teachers at Cole Middle School in Denver, whose response to my special presentations helped determine the direction and content of this work. < previous page

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Page 1 Introduction The gleaming white skull stares empty-eyed through a veil of grass and leaves. The components of an entire skeleton lie scattered across a shallow depression within the field. Here and there, small segments of sun-bleached bone poke through matted grass. Circling on hands and knees, we ferret half-buried, bronze-stained remnants from the loamy soil and clinging vegetation. One by one, we gather bones of varied shapes and separate them into piles: ribs in this one, leg bones in that one, vertebrae over there. This amassed collection, these small hills of bone, mark one animal's final remains. But what type of animal was it? How did it live? What kind of food did it eat? How did it move? How did it behave? From children to adults, hikers to couch potatoes, people are fascinated by bones. Their shape and form spark myriad questions like these. Once you learn how to "read" an animal's skeletal structures, you will be able to gain insight into its environmental lifestyle, that is, what it eats. This book shows you how to identify both individual and combined skeletal structures and use inferential classification to determine an animal's likely eating habits and behavior. Once you understand the basics of inferential classification, you'll be able to group < previous page

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Page 2 animal remains into three environmental lifestyle categories: carnivore, herbivore, and omnivore. Carnivores are strict meat eaters that usually live by predation and/or scavenging. Herbivores are strict plant eaters that live by foraging, browsing, and grazing. Omnivores eat both plant material and animal flesh. They live by hunting or predation, scavenging, and foraging. Inferential classification offers the hobbyist, artist, or outdoor enthusiast a new way to understand animals and encourages a deeper appreciation for nature and her creatures. I have actively collected bones since childhood, and over the past six years this interest has led me to assemble the bones of various animals into sculptures of new creatures. This has allowed me to get a better idea of how skeletal structure relates to function, a scientific discipline known as functional morphology. My art, which has been featured both at galleries and on local news programs, has generated a great deal of interest. The barrage of bone stories and questions from persons of all ages and all walks of life indicates an almost universal fascination with this subject. At the prodding of an eleven-year-old friend, I tested this hypothesis by accepting an offer from his middle-school science teacher to present a lesson on basic skeletal structure and bone collecting to two sixthgrade science classes. This experience was extremely rewarding: The students' overwhelming response verified my initial conjecture

that the public is keenly interested in bones and skeletal structures. Across North America many children and adults are fascinated by the study of bones. Few, however, have the means or technical resources to quickly identify them or comprehend what the structures they find indicate about the environmental lifestyles of the animals. Many publications that address osteology, the study of bones, over-whelm the reader with a withering barrage of technical and taxonomic terminology. While fine for professionals, this technical approach often hinders people not already familiar with the subject. Therefore, I have written this book with a more generalized and understandable approach. Associated with common environmental issues such as ecology, animal behavior, and eating habits, the information included is technical enough for educational use but basic enough for comprehension by a wide audience. < previous page

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Page 3 Chapter 1 Classification Systems Our world is home to many animals. Without some organizational tool, most people would find it extremely difficult to study and understand their vast diversity. Fortunately, scientists have developed classification systems for this purpose, two of which are discussed here: the species-specific view of traditional taxonomy, or systematics, and the general-lifestyle view of inferential classification. Although both systems are helpful, inferential classification is used primarily in this book. To ease into this approach, let's first discuss traditional taxonomy. Traditional Taxonomy The biological science that deals with classification of animals as individuals and groups is called zoology. Traditionally, this science has used the tool of taxonomy to relate animals into an understandable pattern by grouping them according to similarities in skeletal and other biological structures. Taxonomy, or systematics, is defined by Webster's New Collegiate Dictionary as "the orderly classification of plants and animals according to their presumed natural relationships." Many systems have been presented for the classification of animals over the years. In the early eighteenth century, the gifted < previous page

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Page 4 Swedish naturalist and anatomist Carolus Linnaeus developed a standardized binomial classification system (which identifies genus and species) that has achieved universal acceptance. The Linnaean system assumes that animals with similar body construction are members of the same classification group. This system, though expanded and greatly elaborated since its introduction, provides the foundation for modern taxonomy. Taxonomic Classification Taxonomic classification employs a hierarchical succession of groupings called rank-categories, or taxa. Organized in descending order, the highest groupings contain many organisms that share very general characteristics, while the lowest groupings contain fewer members, which are identified by specific characteristics. Implementation of this classification method begins with identifying major groupings of organisms that share a broad similarity in structure. From these main groups subgroups are distinguished, each containing organisms that exhibit increasing similarity of body structure. These subgroups may be subdivided still further, with each successively lower group often consisting of progressively more, but smaller groups.* Usually, the lower a group's standing in the system, the fewer its members. This cascading process of subdivision establishes a hierarchy of classification groups. (See Figure 1.1.) Primary groupings within the Linnaean classification system are kingdom, phylum, group, class, order, family, genus, and species.

Each rank may also have super- and subranks, as shown in Table 1.1. To illustrate how this classification system works, Tables 1.21.5 list the taxonomic classification for domestic dogs, woodchucks, and humans. The first three taxonomic ranks, shown in Table 1.2, are shared by all three animals. Tables 1.3, 1.4, and 1.5 define the major rank-categories of each. *When a group is subdivided, successively lower groups do not always contain more groupings. For example, a genus may contain only one species. < previous page

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Figure 1.1. An illustration of the basic hierarchy of kingdom (K) to genus (G) rankings within traditional taxonomic classification. TABLE 1.1 Taxonomic Rankings (in descending order) Major Subranks Superranks Ranks Kingdom superphylum Phylum supergroup Group subphylum superclass Class subgroup superorder Order subclass superfamily Family suborder supergenus Genus subfamily superspecies Species subgenus subspecies TABLE 1.2 Taxonomic Ranks Shared by a Dog, a Woodchuck, and a Human KingdomAnimaliaAll animals. Phylum ChordataAnimals ClassMammaliaWarmblooded with animals spinal who have cords and hair on hollow their skin vertebrae.

and whose young are nourished through milk glands.

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Page 6 TABLE 1.3 Taxonomic Ranking of a Domestic Dog Genus Canis Dog or OrderCamivoraAnimals FamilyCanidaeAnimals doglike whose diet is whose animals. varied and primary can be partly SpeciesfamiliarisThe food members of herbivorous. source is the genus Incisors, the flesh Canis who canines, and of other have been premolar animals. domesticated teeth are Canine by man. The specialized teeth are common for cutting large and dog. and tearing, conical, with at least and other two grinding teeth are molars still specialized intact. Feet for the are tearing of digitigrade flesh. Feet with are nonretractable plantigrade claws, and (the entire limbs are foot, toes specialized and heel, for touching locomotion the on the ground) or ground. digitigrade (only the toes touching the ground).

Latin Names Classic Latin is the language of preference for nomenclature and terminology in classification systems. There are four major reasons for this. First, Latin is a ''dead" language, meaning it's no longer used for everyday speech. Therefore it can be reserved for a special purpose, such as scientific classification, and not be subject to the changes in word definitions, grammar, and syntax that "live" languages experience. Second, since Latin is the linguistic ancestor of Western languages such as French, Spanish, Italian, and English, people from many nations find it fairly easy to interpret. Third, Latin nomenclature embodies scientific tradition. Latin has < previous page

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Page 7 TABLE 1.4 Taxonomic Ranking of a Woodchuck OrderRodentiaHerbivorous FamilySciuridaeRodents GenusMarmotaBurrowing SpeciesmonaxThe grizzled, animals with two (sometimes thickset with upper omnivorous), marmot of elaborate premolars gnawing the underground and one animals with northeastern societies. lower, and one pair of United no incisors States and infraorbital (front teeth) Canada. canal for in each jaw. the masseter muscle. This canal is an opening in the rostrum, a portion of the skull just forward of the orbitals. been used in this type of work for hundreds of years, and tradition is hard to change. Finally, the use of Latin in taxonomy persists because of history. The science of Western civilization is

founded on the thought and culture of ancient Rome and Greece, and systematics was born of Western culture. In medieval Europe, Latin was a survivor of the Holy Roman Empire, providing one of the few links with the principles of Old Rome and ancient Greece. The Roman Catholic Church wielded great power and inherited Latin as its primary language. In those days, since the church was the main source of education and science, the majority of written works were composed in or translated into Latin. It should be noted that Latin is not the only language used in modern taxonomic nomenclature, just the primary one. French, Greek, Italian, Swedish, German, and other languages are also used but are usually Latinized. Appendix B provides further information on scientific naming, terminology, and word origins. < previous page

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Page 8 TABLE 1.5 Taxonomic Ranking of a Human SpeciessapiensAnimals OrderPrimateBasically FamilyHominidaeAnimals that GenusHomoOnly with a those live on the arboreal prominent animals groundM (tree chin, high with a and walk dwelling) forehead, large upright on or of thin skull brain, two legs. arboreal bones, speech Their hands ancestry, doublecapacity, and feet are animals curved and an differently with spine, and extended specialized fingers, sparse youth. (hands for flat nails, body hair. grasping and and a Humans. feet for reduced walking) and sense of they have a smell. family and tribal social organization. It's fairly easy to read scientific names once you understand the system. Each organism is given a two-part name. The first name designates its genus and the second, its species. For example, a wolf's scientific name is Canis lupus. In Latin the word Canis means dog and lupus means wolf. So Canis

lupus means dog wolf. A domestic dog's taxonomic classification is Canis familiaris. We already know that Canis is the Latin word for dog, and familiaris translates to the English word "familiar." So Canis familiaris means dog familiar. Common Names Few people spout Latin names and terminology during everyday conversation. Instead, most know and refer to animals by their common names, which are often derived or taken directly from languages native to the area where the animals live. For example, "chimpanzee" is taken from chimpenzi in the Kongo dialect and "wolf" is derived < previous page

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Page 9 from the Old English Wulf and more directly from the old High German Wolf. "Chipmunk" has its origins in the Algonquin word chitmunk, "coyote" is taken from the word coyotl in the language of the Nahuatl Indians of western North America, and "woodchuck" comes from the Ojibwa word otchig, meaning fisher or martin, and from the Cree word otcheck. The Arbitrary Nature of Taxonomic Classification The animal kingdom comprises some two dozen phyla and at least 1.5 to 2 million species. This book addresses the taxa found in the kingdom Animalia, phylum Chordata, class Mammalia. The reader should always remember that, save for species, there exists no principle, except perhaps genetics, by which taxonomic classification categories may be absolutely defined. Because of this, it is inevitable that genera, families, and so on as they are presently identified by mammalogists do not exactly compare to those used by ichthyologiststhose who study fishor entomologiststhose who study insects. These differences may reflect a lack of agreement among scientists or may be the result of biodiversity in our world. Whatever the cause of these differences, perhaps someday scientists in all fields will agree on all levels of classification. If you pursue traditional taxonomic classification techniques, a theme beyond the scope of this book, beware of your preconceptions. For example, one of the greatest preconceptions of collectors and classifiers lies in size. While basic skull structures within a family may remain relatively constant, their sizes can vary

considerably. For example, the skulls of a domestic house cat and a lion are quite similar in shape but differ greatly in size. A person used to thinking of members of the cat family, Felidae, as being the size of a tabby may glance at a lion skull and erroneously identify it as a member of the bear family, Ursidae, without bothering to check the details. The rigid specifics of traditional taxonomy can be somewhat overwhelming for beginning collectors and hobbyists. Fortunately, a more broad-based method of animal identification, inferential classification, offers an alternative. Inferential Classification Inferential classification involves analyzing skeletal structures to infer an animal's eating habits, or environmental lifestyle. This system < previous page

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Page 10 encourages the student or hobbyist to develop an understanding of the relationship between skeletal structure and an animal's general behavior. This method doesn't supplant traditional systematics but rather is meant as a tool for people wishing to learn more about how animal structures relate to their environment. General Lifestyle Classifications The theory of convergent evolution maintains that animals who adapt to a certain environmental lifestyle develop similar body structures. This trend toward structural similarity is apparent in the skeletons, particularly the skulls, of animals that fill similar environmental nichesas either predator or prey. These structural similarities may remain relatively constant across species boundaries. Inferential classification assumes that associations of particular skeletal structures apply to certain environmental lifestyles. While such correlations can be made, it should be emphasized that no one structure or combination of structures always indicates specific eating patterns. This is because lifestyle, unlike physical construction, can change if necessary for the animal to survive. For example, a polar bear, like its cousin the black bear, has dentition necessary for an omnivorous lifestyle: cutting incisors, tearing canines, sharp bicuspids, and flat molars that are ideal for grinding plant material. But since plants are scarce in its arctic habitat, the polar bear is left with little choice but to subsist entirely on meat.

Most black bears, in contrast, live in temperate habitats amid a thriving variety of plants and animals. With plant food as easily available as animal flesh, or more so, black bears easily live an omnivorous, though primarily herbivorous, lifestyle. Other animals that sometimes deviate from the lifestyle suggested by their skeletal structure include rats, which, while classified as herbivores, will eat meat if their survival requires it. In all instances, environmental living conditions and available food supply exert pressures that affect an animal's lifestyle and behavior. Chapter 6 discusses behavioral interpretation from skeletal structures at greater length. As stated in the introduction, inferential classification groups animals into three environmental lifestyle categories: carnivores, herbivores, and omnivores. Keeping the previous discussion of structure versus lifestyle in mind, let's examine these lifestyles. < previous page

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Page 11 Carnivores and Insectivores Carnivores subsist primarily upon the flesh of other animalsherbivores as well as smaller carnivores and omnivores. Speed, strength, specialized teeth, and body appendages such as claws are familiar indicators of a lifestyle based on hunting, killing, and consuming prey. Insectivores practice a lifestyle similar to that of carnivores but consume insects rather than animal flesh. For the purpose of this book, insectivores and carnivores are grouped together. Herbivores Herbivores are animals whose primary, if not exclusive, source of nourishment is plants. Specific structures, especially flat teeth, are designed to exploit this specialized food source by engaging in three general modes of eating behavior: gnawing (rodents), browsing (ruminants), and cropping (perissodactyls). Omnivores Omnivores eat whatever food they can find, grazing on plants just as easily as they consume meat. These ultimate opportunists can often be found scavenging among the leftovers of carnivore kills as well as nibbling forage. This flexibility allows omnivores to adapt their diets to available food sources. For example, when vegetation is plentiful, an omnivore's diet may consist primarily of plant matter supplemented by animal flesh. When vegetation is scarce, the animal may eat mostly meat. This variable diet requires skeletal structures, especially the skull,

that combine herbivorous and carnivorous features. Interpreting such structures to infer an omnivorous lifestyle can be difficult, however. The only skeletal structures that can be used to reliably infer an omnivorous lifestyle are the presence of well-developed molars in conjunction with a full complement of incisors, canines, and bicuspid teeth in both jaws. Outside of this, it is easier to ascribe a carnivorous or herbivorous lifestyle to an animal's skeletal remains than an omnivorous one. The Skeleton Inferential classification uses observations of related structures within a skeleton, called function groups, to infer the probable environmental lifestyle of an animal. The three primary function groups are made up < previous page

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Page 12 of bones that work together within the larger skeletal system: the skull, the limbs, and the vertebrae and ribs. The Skull People are fascinated by skulls. Perhaps this is because the skull defines the seeing-hearing-smelling-biting-eating end of a creature and, therefore, its "personality." Regardless, this function group often becomes the focus of interest and study almost to the exclusion of the rest of the skeleton. As defined in this book and discussed in detail in chapter 2, the skull function group consists of six easily recognizable structures: dentition, the jaw, the nasal cavity, the orbits (eye sockets), the zygomatic arch, and the cranium. These structures, along with the location of jaw muscle attachment positions, offer the greatest amount of immediate information concerning an animal's environmental lifestyle. (See Figure 1.2.) The Limbs When in their study of skeletal structure people emphasize the biting end of an animal, they often disregard the animal's stepping, tromp-

Figure 1.2. The bold area indicates the skull function group. < previous page

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Page 13 ing, and clawing portion. In inferential classification, skeletal structures used by a mammal to move itself across or through its habitat are essential to forming a complete picture of its environmental lifestyle. The limb function group, detailed in chapter 4, comprises the front and back legs. Each can be divided into three parts. The front leg grouping includes the front feet (claws and bones), the leg bones (radius, ulna, and humerus), and the shoulder blade. The back leg is made up of the back feet (claws and bones), the leg bones (fibula, tibia, and femur) and the hipbone. Analysis of these structures offers insight into the posture, locomotion, attack or escape capabilities, and probable terrain common to the animal's environment. (See Figure 1.3.) Vertebrae and Ribs The vertebrae and ribs function group, detailed in chapter 5, provides the skeletal framework to which the other function groups attach. The vertebral column protects the spinal cord and supplies the connecting structure that ties the entire skeletal system together. The ribs, in addition to protecting the

Figure 1.3. The bold areas indicate the limb function group. < previous page

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Page 14 heart and lungs, also provide the support platform to which the scapula, or shoulder blade, is attached. The information derived from these structures is essential to assembling a complete picture of an animal's environmental lifestyle. Both can be used to infer posture, mass, and an animal's degree of flexibility during motion. (See Figure 1.4.) Conclusion Systematics and inferential classification are both useful in understanding animals, but they assume different levels of knowledge on the part of the reader. Traditional taxonomy moves beyond inference and into perceived specifics. To fully utilize this system requires exposure to systematics and a background in zoology or mammalogy. The inferential method is intended for persons of any age who are unfamiliar with, or have just a basic knowledge of, concepts within this field of study. For these people, this book offers a practical introduction into the joys of skeletal interpretation.

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Page 15 A note of caution for would-be collectors: Be aware that few skeletons are found complete. Although classifying an entire skeleton can be a complex procedure, identifying partial remains is even more challenging. Before attempting to classify any skeletal remains, either through traditional taxonomy or inferential classification, take into account as many structural components as possible. The more information you have to start with, the more likely you are to reach correct conclusions. < previous page

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Page 16 Chapter 2 The Skull More than any other skeletal feature, the skull is a great source of information about an animal's environmental lifestyle. The term ''skull" refers to the bony or cartilaginous case that forms the skeleton of the head. This case encloses and protects the brain as well as the chief sense organs: eyes, inner ears, sinus, and tongue. A complete skull includes an immobile upper jaw, or maxilla, and a movable lower jaw, or mandible. The many bones and plates of a mammal's skull fit together like a jigsaw puzzle. The jagged-edged surfaces along which these plates meet are called sutures. Sometimes, as in birds, the plates fit together so tightly that the sutures do not show. (See Figure 2.1.) The study of skull construction, called craniology, is often limited to human crania. Researchers in this field have identified more than fifty separate structures that can be used to classify animals at the species level. For our purposes of inferential classification, however, we will look at major structural groups. It is important to remember that a skull must be considered as a whole during classification, as few individual structures provide enough information to positively identify the animal's environmental lifestyle. Six easily recognizable skull structures are especially useful for inferential classification of < previous page

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Figure 2.1. Top views of basic cranial suture lines in dog and horse skulls. skulls: dentition, the jaw, the nasal cavity, the orbits (eye sockets), the zygomatic arch, and the cranium. The relationships among these structures and the attachment positions of jaw muscles also provide important clues. (See Figure 2.2.) Dentition Dentition refers to teeth and arrangement of teeth within an animal's jaws. There are four basic types of teeth: incisors, canines, bicuspids, and molars. (See Figure 2.3.) Incisors are the forward, or front, teeth within a jaw whose sharp edges provide excellent cutting surfaces. Their presence or absence

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Figure 2.2. The six basic skull structures used in inferential classification. the upper jaw is a good indicator of the animal's environmental lifestyle. Also called eyeteeth, canines are often conical, pointed teeth located between the incisors and the first premolars. They are ideal for gripping and tearing. Also known as the first premolars, bicuspids have two conical points and follow the canines. Like canines, they are used for gripping and tearing. Molars follow the bicuspids and, depending upon the lifestyle of the mammal, may be flat, for grinding, or serrated, for cutting. Molar form and structure will often determine an animal's aptitude for a particular environmental lifestyle.

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Figure 2.3. Human dentition. Note the four major dental groupings. ence often indicate specific environmental lifestyles and eating habits. Following are discussions of dentition in each of the three environmental lifestyle categories. Carnivore Dentition Since animal tissues are softer than those of plants, contain no cellulose, and tear fairly easily, carnivores have teeth with sharp points and serrated edgesideal for tearing and cutting flesh. Carnivore

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Page 20 incisors are narrower and much smaller than the other teeth and sport beveled sharp edges, excellent for piercing and cutting. The canines (eyeteeth) are highly developed in carnivores and are usually longer than the other teeth. Their conical shape and positioning in the jawoften pointing straight down from the maxilla and straight up from the mandibleare ideal for holding, tearing, and slashing. Bicuspids (first premolars), capped with twin conical peaks, are also excellent for cutting or shearing. In carnivores, these teeth along with the molars are often serrated and are called the carnassials, or cut-

Figure 2.4.

Views of common carnivore dentition. < previous page

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Page 21 ting blade teeth.In true carnivores, molars usually maintain a serrated, or jagged-edged, appearance that is perfect for cutting; this structural construction is particularly noticeable in felines. Molars with flat grinding surfaces are nonexistent or limited to one very small, almost vestigial narrow molar in the far rear of the upper jaw. (See Figure 2.4.) Herbivore Dentition Features unique to nearly all herbivores are flat molars and the absence of pointed canine teeth and bicuspids in both the maxilla and the mandible. But just because canines and bicuspids don't develop in most herbivores as they do in carnivores doesn't mean they can't. For example, the herbivorous Malaysian musk deer, whose skull is shown in Figure 2.5, sports well-developed canine teeth. Also, some large North American herbivores such as elk and horses develop rudimentary canine teeth called wolves teeth. (See Figures 3.26 and 3.30 in chapter 3.) Additional unique adaptations in dental structure reflect diverse methods of consuming food as seen in the three groupings of herbivores: rodents, ruminants, and perissodactyls.

Figure 2.5. A side view of the skull of a Malaysian musk deer, which is not native to North America. Notice the well-developed, tusklike canine teeth.

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Page 22 Rodents Rodentssquirrels, rats, and so forthsport a single pair of long, curved, chisel-edged incisors in both their upper and lower jaws. Being the only incisors that develop in these animals, they are the single most indicative feature of a rodent skull. Well-developed molars bevel inward and have a level, often corrugated surface. (See Figure 2.6.) Ruminants In ruminants, such as cows, incisors are present in the mandible but absent in the maxilla and are wide with sharp, beveled edges. Their molarsflat, well formed, and slanting slightly inwardhave ridges on their grinding surfaces. (See Figure 2.7.)

Figure 2.6.

Views of herbivore dental construction common in rodents. < previous page

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Figure 2.7. Views of herbivore dental construction common in ruminants. Perissodactyls In striking contrast to ruminants, perissodactyls such as horses have wide, sharp-edged incisors in both their upper and lower jaws. As with ruminants and rodents, their flat-ridged molars bevel slightly inwardexcellent structures for grinding plant materials. (See Figure 2.8.)

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Figure 2.8. Views of herbivore dental construction common in perissodactyls. Omnivore Dentition Although omnivores come in a wide variety of sizes and shapes, the basic structure of their dentition remains the same: a complete, welldeveloped complement of incisors, canines, bicuspids, and molars in both the upper and lower jaws. As with other body structures of omnivores, their teeth reflect a combination of both herbivore and carnivore structures.

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Figure 2.9. Views of omnivore dental construction from a pig. < previous page

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Figure 2.10. Views of omnivore dental construction from a dog. Like carnivores and perissodactyl herbivores, omnivores have incisors in both the maxilla and the mandible. Bevel-edged for cutting, these teeth may be wide or narrow and nearly the same size as or decidedly smaller than the canine teeth. Omnivore canine teeth may be long and specialized, as in most carnivores, or short and unspecialized; they are often the same length

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Figure 2.11. Views of omnivore dental construction from a bear. as the surrounding teeth. Regardless of their size, however, these teeth remain useful for tearing both plant and animal flesh. Bicuspids, like the canine teeth, may be equal in size and shape to those of true carnivores, or much flatter, though still similar in structure. These teeth sport sharp edges for tearing plant and animal flesh and sometimes shallow, flat areas for grinding. When fully developed, omnivore molars have large, flat grinding surfaces, but some omnivores (such as foxes) may also sport both full

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Page 28 and fractional flat grinding surfaces while retaining among some molars the carnassial shape common to carnivores. (See Figures 2.3 and 2.92.11.) Jaws A mammal's skull contains two jaws: The maxilla, or upper jaw, is fused to the main portion of the skull below the nasal cavity; the mandible, or lower jaw, is movable and is attached at the hinge joints just forward of the ears. These structures mirror each other in shape and dimension. For example, if the maxilla is long and narrow, the mandible will be long and narrow, too. If the mandible is short and wide, the maxilla will be short and wide. (See Figure 2.12.) Jaws provide a foundation for leverage and gripping by the teeth. When working, the maxilla remains in its fixed position while the mandible moves against it. These movements may be up and down, forward and back, or side to side. Powerful masseter and temporalis muscles attach the mandible to the cranium, providing crushing and gripping strength.

Figure 2.12. The maxilla and mandible of a human skull. < previous page

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Page 29 Like dentition, jaw shape is a good indicator of an animal's environmental lifestyle. Because its shape exhibits the greatest variance among environmental lifestyles, however, the mandible can be considered the better of the two jaw structures to use for inferential classification. Carnivore Jaws In carnivores the mandible is often at least slightly curved, allowing greater pressure to be exerted at the front of the jaw, where the canines and incisors reside. This gives the animal more strength for holding and tearing food. (See Figure 2.13.)

Figure 2.13. Typical carnivore mandibles. Notice the curved shape.

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Page 30 Herbivore Jaws In the long, flat jaws common among many herbivores, the mandible tapers from a wide back to a narrower front. This construction allows greater pressure to be exerted along the mid to back portions of the jaw than at the front. (See Figure 2.14.) Not all herbivores share this lower jaw construction, however. Rodents have curved or slightly curved mandibles that allow bite pressure to be maximized at both the incisors and the molars. (See Figure 2.15.) Omnivore Jaws The lower jaws of omnivores share attributes of carnivore and herbivore mandibles and come in three basic shapes: short and flat, as in humans; long and flat to slightly curved, as in pigs and bears; and long and curved, as in dogs and opossums. (See Figure 2.16.) Nasal Cavity The sense of smell is vital to all mammals. The nasal cavity, home to the olfactory organs, is the portion of the skull that houses and protects the sinus membranes. It can be long and narrow, as in deer and wolves; long and wide, as in cows; short and flat, as in humans and cats; or short and narrow, as in otters. The nasal cavity's size and shape often affects the placement of and distance between the eye sockets of a mammal. Long-wide nasal structures tend to space eye sockets farther apart and rotate them to the side. Long-narrow and short-blunt nasal structures tend to space

eye sockets closer together and rotate them to face forward. (See Figure 2.17.) Carnivore Nasal Cavity In true carnivores, the nasal cavity, often short and blunt, as in felines, can also be short and narrow, as in otters. (See Figure 2.18.) Herbivore Nasal Cavity The nasal cavity in herbivores is usually long, housing an efficient sinus. The width of this structure differs greatly from species to species. For example, the nasal cavity of a cow is long and wide, but in a deer or squirrel, it is long and narrow, and in porcupines, it is short and somewhat pointed. (See Figure 2.19.) < previous page

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Figure 2.14. The long flat mandible shape typical of ruminant and perissodactyl herbivores. < previous page

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Figure 2.15. Rodent mandibles. Notice the curved shape. < previous page

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Figure 2.16. The range of omnivore jaw shapes. < previous page

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Figure 2.17. A comparison of four basic nasal structures. Omnivore Nasal Cavity Omnivore nasal cavities come in three general shapes: short and flat, as in humans; long and narrow, as in opossums; or long and medium-wide, as in bears. (See Figure 2.20.) < previous page

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Figure 2.18. Examples of carnivore muzzles. Note the nasal structures and orbits. Orbits Orbits, or eye sockets, form the framework that supports and protects the eyes. Their shape, size, and position in a skull can indicate the animal's environmental lifestyle. Eye-socket positions in mammal skulls range between two extremes: rotated facing forward or rotated sideways facing outward from the side of the head. Forward-facing eye sockets permit the fields of vision of each eye to overlap. This parallax allows the brain to perceive the same image

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Figure 2.19. Examples of herbivore muzzles. Note the nasal structures and orbits. from two different perspectives and so fix an object in space. Called binocular vision, this type of perception allows an animal to sense depth, distances, and three-dimensional imagesvery handy when attacking prey or dodging a predator. (See Figure 2.21.) < previous page

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Figure 2.20. Examples of omnivore muzzles. Note the nasal structures and orbits. Eye sockets set on the sides of the skull require the eyes to face outward in opposite or near-opposite directions, a position in which their fields of vision do not overlap. This results in monocular vision, which limits an animal's perception to flat, two-dimensional images, preventing the sensing of depth and distances. Although this may seem less desirable than binocular vision, monocular vision does have advantages, including great peripheral vision. This allows an animal

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Figure 2.21. The overlapping of sight fields that produces binocular vision, illustrated using the orbital structures of an elephant shrew, a nonnative of North America. to see farther to the rear and increases its ability to sense motionextremely important if your enemies tend to sneak up from behind and use fast, quick movements when they attack. (See Figure 2.22.) Carnivore Orbits The predominant position for carnivore orbits is facing forward or slightly forward. This arrangement facilitates binocular vision and depth perception, both essential for hunting and attack. (See Figure 2.18.) Herbivore Orbits Orbit position in herbivore skulls is often graded between forward facing and side facing and varies among animals. The eye sockets of most rodents are rotated forward in the skull, allowing binocular vision. Bulky, often slow-moving animals such as cows and buffalo tend to have eye sockets rotated to the side in their skulls for monocular vision. Faster-moving animals such as antelope and deer have < previous page

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Figure 2.22. The independence of sight that produces monocular vision, illustrated using the orbital structures of a bison. orbitals rotated slightly forward, often far enough to provide limited binocular vision. (See Figure 2.19.) Omnivore Orbits Omnivores share the carnivore and rodent adaptation of forward rotated or slightly forward rotated orbitals. This positioning allows binocular vision and good depth perception. (See Figure 2.20.) Zygomatic Arches The zygomatic arches are the portions of a skull that form the cheekbones and extend to the back along each side of the skull, attaching above and slightly forward of the ears. They are composed of two bones: The jugal bone, or cheekbone, connects with the squamosal, which in turn connects to the cranium just above and in

front of the ears. The greatest distance between the outside edges of the zygomatic arches on either side of the cranium is called the zygomatic breadth.(See Figure 2.23.) < previous page

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Figure 2.23. Bold areas in this image reference the zygomatic arch and its component structures, the jugal and the squamosal. Together these structures form the zygomatic arch. Zygomatic arches are important for inferential classification because their size and distance from the cranium indicate the relative size of the temporalis muscles, which pass between them and connect the back of the mandible to the cranium. The larger the opening, the larger and stronger the temporalis muscles, and the more likely the animal is to exhibit carnivorous tendencies. (See Figure 2.24.) The relationship between zygomatic breadth and cranium size and environmental lifestyle can best be shown by comparing the top view of the skulls illustrated in chapter 3. The figures in this chapter provide top and side views of carnivore, herbivore, and omnivore skulls. Carnivore Zygomatic Arches Carnivore skulls tend to have large zygomatic breadths. The zygomatic arches and the ''hole" they form with the cranium accommodate the passage of well-developed temporalis muscles. Although this arrangement provides greater space for the temporalis muscles, it also provides a strong anchor position for the masseter muscles, which raise the lower jaw. (See Figures 3.13.10 of chapter 3.) < previous page

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Figure 2.24. A comparison of the zygomatic breadths of a horse and a wolf. Herbivore Zygomatic Arches The skulls of ruminants and perissodactyls have small zygomatic breadths. While such an arrangement decreases the space between the cranium and the zygomatic arches, offering less room for the temporalis muscles, it does provide a stronger anchor position for the masseters. Rodent skulls, however, are similar to carnivore skulls in that they have large zygomatic breadths. Compare similarities and differences among herbivore arch structures by studying Figures 3.153.30 in chapter 3. Omnivore Zygomatic Arches In omnivores, the relative breadth and position of the zygomatic arches in relation to the cranium range between those of herbivore

and carnivore skulls. Although these structures can be large, as in bears and foxes, they can also be relatively small, as in humans and pigs. (See Figures 3.313.42 in chapter 3.) < previous page

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Page 42 Cranium The cranium, or dome, is the portion of the skull that protects and houses the brain. This structure is important in classification because its outward cross-sectional shape often varies according to an animal's environmental lifestyle. The back portion of the cranium comprises two paired bones called the parietal bones. The suture line joining these bones forms the sagittal crest, which runs longitudinally to the posterior or back of the skull. This crest can be pronounced (forming a peak), reduced (forming a slight bump), or smooth (forming a rounded or flat surface). Whatever the case, the joining of the plates that form the sagittal crest often determines the final appearance of the cranium. Cranial shape indicates not only the surface area available to anchor jaw muscles but also muscle size and strength. Usually, the larger the sagittal crest, the larger the temporalis muscles that attach along its length; a smooth or flat cranium indicates smaller temporalis muscles that must anchor farther down its sides to maintain sufficient purchase. In cross-sectional appearance, three generalized cranial shapes may be considered common among mammals: smooth-rounded, as in humans and deer; smooth-flat, as in cows; and peaked, as in dogs and cats. (See Figure 2.25.)

Figure 2.25. Three cross-sectional shapes common among mammal crania: smooth-rounded, smooth-flat, and peaked. < previous page

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Page 43 Carnivore Crania Carnivore crania often have a pointed appearance because of their pronounced sagittal crest. This crest provides a secure anchor for longer, more developed temporalis muscles. (See Figures 3.13.10 in chapter 3.) Herbivore Crania The skulls of ruminants and perissodactyls come in one of two basic cranial shapes: smooth-rounded and smooth-flat. These shapes house smaller temporalis muscles, as a reduced or smooth sagittal crest doesn't provide the anchorage required by large, welldeveloped temporalis muscles. (See Figures 3.233.29 in chapter 3.) Rodents are the exception to the herbivore rule. Rodent skulls can be round and smooth or slightly peaked from a reduced sagittal crest. (See Figures 3.163.22 of chapter 3.) Omnivore Crania Omnivore crania come in a variety of shapes, from the high peaks common among carnivores to the smooth-round and smooth-flat domes prevalent among herbivores. (See Figures 3.313.43 in chapter 3.) Muscle Attachment Positions Two major muscle groups, the masseter and the temporalis, work to close the lower jaw. They attach to the skull at the zygomatic arch, the cranium, and the lower jaw. The size and positioning of these muscles, when associated with other skull features, can help identify

an animal's environmental lifestyle. Temporalis muscles attach along the rear of the lower jaw and anchor along the sides or top of the cranium. They provide power to the forward portion of the jaws where the incisors, canines, and bicuspids reside. Masseter muscles attach between the sides of the zygomatic arches and the rear portions of the lower jaw. They provide power for the back of the jaws, where the molars reside. Carnivore Muscle Attachments Muscle attachments in carnivore skulls are located where they will give the greatest strength to muscles whose major function is to aid the jaws in holding and crushing prey while the animal tears and rips < previous page

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Page 44 flesh. Therefore, the temporalis muscles attach to the rear portions of the lower jaw, run beneath the zygomatic arches, extend up along the sides of the skull, and attach near the top of the cranium, usually at the sagittal crest. Their length and points of anchorage give a tremendous amount of leverage and power to the front of the lower jaw. In this arrangement, temporalis muscles are stronger than masseters. Masseter muscles attach between the zygomatic arches and rear portions of the lower jaw. Usually smaller than the temporalis muscles, they produce the power for crushing and cutting with the back teeth, or molars. (See Figure 2.26.)

Figure 2.26.

Attachment points for the temporalis and masseter muscles on a European badger skull. < previous page

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Page 45 Herbivore Muscle Attachment Positions Ruminant and perissodactyl skull structures are designed to accommodate jaw muscles whose major function is to provide the power for crushing and grinding plant materials with the rear portions of the jaws. (See Figure 2.27.) The temporalis muscles attach along the rear portions of the lower jaw and anchor the sides of the cranium near the temple. Their relative shortness and cranial anchor positions limit the amount of leverage and power they can give to the front of the relatively flat jaws common among herbivores. The masseter muscles attach between the zygomatic arches and the back of the lower jaw. In herbivores, these muscles are often larger and stronger than the temporalises. Strong masseter muscles greatly enhance grinding side-to-side movements and crushing strength in the rear portion of the jaw. Although smaller temporalis muscles limit the total power of the front of the jaw, large masseter muscles offer impressive leverage to the incisors of perissodactyls and ruminants. Ask anyone who has been bitten by a horse. (See Figure 2.27.) Jaw muscle attachments in rodents are more like those of omnivores than those of other herbivores. A curved jaw, often reduced sagittal crest, and forward-facing orbits all contribute to providing positioning and development of strong, well-developed temporalis and masseter muscles. (See Figure 2.28.) Omnivore Muscle Attachment Positions

Omnivore jaws are used to crush and grind plant material with the back of the jaws as well as tear and cut animal flesh and plant material with the forward portion of the jaws, so their muscles must be attached where they can perform both tasks. The temporalis muscles attach to the rear portions of the lower jaw, run beneath the zygomatic arches, and finally extend and attach to the sides of the cranium. Along this route they commonly anchor in one of two cranial positions: lateral, as with herbivores, or dorsal, as with carnivores. A lateral attachment anchors temporalis muscles along the sides of the cranium near the temples. In this position, their limited length and cranial anchorage deliver a reduced, though more than adequate, amount of power to the front of the jaws. In this situation, the temporalis muscles are often equal to or slightly weaker in strength than the masseters. A dorsal attachment anchors temporalis muscles along the sagittal < previous page

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Figure 2.27. Muscle attachment points for masseter and temporalis muscles on ruminant and perissodactyl skulls. crest near the top of the cranium. This position offers the muscles superiority in length and anchorage, thereby giving a great amount of power to the forward portion of the jaws. In this arrangement, temporalis muscles are often stronger than or equal in strength to masseters. Omnivore masseter muscles attach between the zygomatic arches

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Figure 2.28. Muscle attachment points for masseter and temporalis muscles on rodent skulls. and the rear portions of the lower jaw. In omnivores, these muscles range from roughly equal in size and strength to somewhat larger and slightly stronger than the temporalis. Strong masseters greatly enhance grinding side-to-side movements and crushing strength in the rear portion of the jaw. (See Figure 2.29.) < previous page

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Figure 2.29. Muscle attachment points for masseter and temporalis muscles on an omnivore skull. < previous page

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Page 49 Conclusion When specifying which skull structures will be used for classification, recognize that adaptive and environmental influences often encourage the development of similar structural shapes in mammals across lifestyle boundaries. Because of this, it is difficult to say with absolute certainty that specific structural shapes in a skull indicate a particular environmental lifestyle. For example, an elongated muzzle is common to herbivores, carnivores, and fourlegged omnivores. It is for this reason that inferential classification considers no one structure definitive of a specific environmental lifestyle and instead suggests that structures be considered as a whole. < previous page

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Page 50 Chapter 3 Skulls Illustrated This chapter presents a series of illustrations depicting skulls from a variety of North American land mammals. These images are divided into the three environmental lifestyle categories: carnivore, herbivore, and omnivore. An animal's common name and taxonomic family rank are provided with each entry. Appendix C lists complete traditional taxonomic order-to-species rankings for each mammal mentioned in this book. Before presenting these illustrations, the following point must be clarified. This work classifies several animals as omnivores that traditional taxonomy places in the order Carnivora. The long canine teeth generally associated with members of this order conjure images of fanged creatures whose sole purpose in life is the rending, shredding, and consuming of animal flesh. Use of this term as a group rank indicates a two-hundred-or-more-year-old preconception based solely on the presence of these dental structures. Many members of this order also have flat, well-developed molars, however, indicating that vegetation is an important secondary food source. The relative length and width,* in centimeters, of skulls *Width refers to the zygomatic breadth. < previous page

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Page 51 sketched for this chapter are presented in each figure caption. These measurements, provided for approximate scale, should not be considered absolutes. Relative dimensions will vary among individuals, depending on age and sex. Carnivores and Insectivores Carnivores and insectivores share similar environmental lifestyles based on hunting and consuming prey, so they have similar skull structures. Although their dentition is markedly different, with the teeth of insectivores being more serrated and undifferentiated than those of carnivores, the primary difference between these two groups is size. Most insectivores are smaller than carnivores, and insectivore skulls are often one-half inch or less in length. Common Carnivore Skulls From the vast number of carnivores in North America, members from two prominent families have been chosen to provide a cross section of common carnivore skulls: Felidae and Mustelidae. Felidae Domestic cats, lynx, bobcats, and cougars, or mountain lions, are members of the family Felidae. (See Figures 3.13.4.) Mustelidae Weasels, wolverines, skunks, badgers, river otters, and martens are members of the family Mustelidae. (See Figures 3.53.10.) As discussed in chapter 1, an environmental lifestyle may be considered an interactive function of environmental and structural

constraints. Thus, an animal's actual lifestyle can be different from that suggested by its skull structures. For example, the polar bear may be considered the only strictly carnivorous member of the family Ursidae. Its skull strongly resembles those from related omnivorous family members illustrated in Figures 3.313.33. Similarly, the arctic wolf may be considered the only truly carnivorous member of the family Canidae. Its skull is similar to those of the related omnivorous family members illustrated in Figures 3.343.38. < previous page

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Figure 3.1. Top and side views of a domestic cat skull. Length (8 cm), width (6 cm). < previous page

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Figure 3.2. Top and side views of a mountain lion skull. Length (20.5 cm) , width (14.1 cm). < previous page

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Figure 3.3. Top and side views of a lynx skull. Length (12.2 cm), width (9.1 cm). < previous page

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Figure 3.4. Top and side views of a bobcat skull. Length (12.5 cm), width (9.3 cm). < previous page

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Figure 3.5. Top and side views of a badger skull. Length (13 cm), width (8.2 cm). < previous page

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Figure 3.6. Top and side views of a pine marten skull. Length (8.5 cm), width (4.6 cm). < previous page

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Figure 3.7. Top and side views of a skunk skull. Length (6.3 cm), width (3.9 cm). < previous page

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Figure 3.8. Top and side views of a weasel skull. Length (5 cm), width (2.9 cm). < previous page

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Figure 3.9. Top and side views of a wolverine skull. Length (15.8 cm), width (10.7 cm). < previous page

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Figure 3.10. Top and side views of a river otter skull. Length (10.8 cm), width (7.3 cm). < previous page

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Page 62 Common Insectivore Skulls Although many mammals, such as skunks and some rodents, include insects in their diets, only members of several specific orders and families lead strict insectivorous lifestyles. These include Soricidae, Talpidae, Vespertilionidae, and Dasypodidae. Soricidae Shrews are members of the family Soriddae. (See Figure 3.11.) Talpidae Moles are members of the family Talpidae. (See Figure 3.12.)

Figure 3.11. Top and side views of a common shrew skull. Length (2.1 cm), width (1 cm).

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Figure 3.12. Top and side views of an eastern mole skull. Length (3.5 cm), width (1.8 cm). < previous page

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Figure 3.13. Top and side views of a big brown bat skull. Length (2 cm), width (1.3 cm). < previous page

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Page 65 Vespertilionidae Bats form many families in the order Chiroptera. Two prominent North American bats, the common big brown bat and the cave bat, are members of the family Vespertilionidae. (See Figures 3.13 and 3.14.)

Figure 3.14. Top and side views of a cave bat skull. Length (1.6 cm), width (1 cm). < previous page

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Page 66 Dasypodidae Armadillos are members of the family Dasypodidae. Travelers in the southern United States have probably spotted these animals trundling off into the undergrowth along roadsides or squashed flat in the roadway. (See Figure 3.15.)

Figure 3.15. Top and side views of an armadillo skull. Length (7.2 cm), width (3.2 cm). < previous page

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Page 67 Herbivores A herbivorous lifestyle provides its practitioners with access to a fairly reliable and diverse source of plant material. Although the variety of plant life is often extensive, not all herbivores can eat all plants, and some plants have fairly effective defenses against their would-be consumers. Large amounts of cellulose make plant tissues tough and difficult to tear. As discussed in the previous chapter, herbivores sport dentition that can rasp, crush, and grind, allowing them to exploit this food source. Skulls of Common Herbivores Most North American herbivores can be assigned to one of three basic groups: rodents, ruminants, or perissodactyls. Rodents Rodents form the order Rodentia, which includes such mammals as mice, beavers, chipmunks, squirrels, and porcupines. (See Figures 3.163.22.) Rabbits are members of the order Lagomorpha. Since they have strong similarities in skull structures and identical environmental lifestyles to rodents, this book groups them together. Because their skull structures look similar, inexperienced collectors often confuse the two. To avoid misclassification, collectors should note whether the skull has large, open, weblike structures just forward of the eyes, along either side of the nasal cavity. If they're there, you have a rabbit skull. (See Figure 3.23.)

Ruminants Most ruminants belong to the order Artiodactyla, which includes such mammals as cows, sheep, goats, and bison from the family Bovidae and antelope, deer, and elk from the family Cervidae. (See Figures 3.243.29.) Perissodactyls Perissodactyls form the order Perissodactyla, which includes members of the family Equidae, such as horses and mules. (See Figure 3.30.) < previous page

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Figure 3.16. Top and side views of a chipmunk skull. Length (3.8 cm), width (2 cm). < previous page

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Figure 3.17. Top and side views of a beaver skull. Length (12.8 cm), width (8.6 cm). < previous page

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Figure 3.18. Top and side views of a pocket gopher skull. Length (3.6 cm), width (2.1 cm). < previous page

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Figure 3.19. Top and side views of a muskrat skull. Length (6.5 cm), width (4.1 cm). < previous page

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Figure 3.20. Top and side views of a Wyoming ground squirrel skull. Length (3.9 cm), width (2.4 cm). < previous page

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Figure 3.21. Top and side views of a porcupine skull. Length (9.8 cm), width (6.6 cm). < previous page

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Figure 3.22. Top and side views of a gray squirrel skull. Length (6.2 cm), width (3.5 cm). < previous page

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Figure 3.23. Top and side views of a rabbit skull. Length (6.5 cm), width (3.4 cm). < previous page

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Figure 3.24. Top and side views of a cow skull. Length (45.6 cm), width (20.5 cm). < previous page

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Figure 3.25. Top and side views of a deer skull. Length (26.3 cm), width (10.3 cm). < previous page

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Figure 3.26. Top and side views of an elk skull. Length (42 cm), width (17.2 cm). < previous page

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Figure 3.27. Top and side views of a goat skull. Length (21.9 cm), width (10.4 cm). < previous page

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Figure 3.28. Top and side views of a sheep skull. Length (26.7 cm), width (14 cm). < previous page

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Figure 3.29. Top and side views of a bison skull. Length (60 cm), width (45 cm). < previous page

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Figure 3.30. Top and side views of a horse skull. Length (49.5 cm), width (19.1 cm). < previous page

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Page 83 Omnivores An omnivorous diet consists of both plant material and animal flesh. Lack of a reliable single food source tends to encourage a diversitybased survival strategy where both plant and animal flesh prove important in an animal's diet. Fluctuations in environmental conditions may have encouraged the development of omnivores, perhaps one reason why omnivore skulls sport structures similar to those of both herbivores and carnivores. Common Omnivore Skulls An omnivorous lifestyle is shared by members from a wide variety of orders and families. This lineage illustrates that, regardless of classic taxonomic groupings and differences in skull shapes, an omnivorous lifestyle is common. This section provides skull illustrations from six families. Ursidae Bears form the family Ursidae, and although most of its members are omnivorous, the polar bear, as discussed earlier, is carnivorous. (See Figures 3.313.33.) Canidae Members of the family Canidae include domestic dogs, wolves, foxes, and coyotes. While bearing many structures adapted for eating meat, they also sport teethdeveloped flat rear molarsfor grinding plants and are known to regularly consume vegetable matter. (See Figures 3.343.38.)

Didelphidae Opossums are the only member of the family Didelphidae. (See Figure 3.39.) Procyonidae Many of the skull adaptations in members of the family Canidae exist in the skull structure of raccoons, who form the family Procyonidae. (See Figure 3.40.) < previous page

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Figure 3.31. Side and top views of a black bear skull. Length (29.2 cm), width (16.6 cm). < previous page

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Figure 3.32. Side and top views of a brown bear skull. Length (31.8 cm), width (18.1 cm). < previous page

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Figure 3.33. Side and top views of a grizzly bear skull. Length (30.5 cm), width (14.2 cm). < previous page

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Figure 3.34. Side and top views of a coyote skull. Length (15.2 cm), width (7.5 cm). < previous page

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Figure 3.35. Side and top views of a domestic dog skull. Length (15.2 cm), width (7.5 cm). < previous page

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Figure 3.36. Side and top views of another domestic dog skull. Length (10.6 cm), width (8.6 cm). < previous page

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Figure 3.37. Side and top views of a fox skull. Length (12.3 cm), width (6.6 cm). < previous page

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Figure 3.38. Top and side views of a wolf skull. Length (26 cm), width (13.8 cm). < previous page

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Figure 3.39. Top and side views of an opossum skull. Length (12.1 cm), width (6.1 cm). < previous page

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Figure 3.40. Top and side views of a raccoon skull. Length (10.4 cm), width (6.4 cm). < previous page

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Figure 3.41. Side and top views of a human skull. Length (19.4 cm), width (17.2 cm). < previous page

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Figure 3.42. Side and top views of a pig skull. Length (23.8 cm), width (13 cm). < previous page

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Figure 3.43. Side view of a collared peccary skull. Length (23.6 cm), width (10.8 cm). < previous page

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Page 97 Homonidae Humans are the only ''native" members of the family Homonidae in the order Primate found in North America. Any supermarket will attest to their omnivorous nature. (See Figure 3.41.) Suidae and Tayassuidae Pigs and peccaries are omnivorous members of the order Artiodactyla, families Suidae and Tayassuidae respectively. Their omnivorous lifestyle contrasts sharply with the mostly herbivorous members from this order. (See Figures 3.42 and 3.43.) An important point to remember is that not all animals are native to this continent. Humans have introduced exotics into new ecosystems as petsdogs, cats, and the European badgerand work/food animalshorses, oxen, and cows. Presented alongside native inhabitants, the animals depicted in this chapter represent an excellent cross section of the current inhabitants of North America. < previous page

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Page 98 Chapter 4 The Limbs A mammal uses its limbs primarily for locomotion and secondarily for defense and attack. The development and arrangement of bones and structures within a limb affect an animal's ability to navigate various types of terrain, such as rocky areas, mountains, swamps, plains, and forested tracts. The limb function group includes two structural assemblages: the front limbs and the back limbs. These structures are usually modified to fit a mammal's particular mode of life. For example, bats have wings, ungulates, such as horses, have single-digit hooves, and humans have hands for grasping. (See Figure 4.1.) Most mammals are tetrapods, or four-footed animals, while some, such as humans, are bipeds, or two-footed creatures. In both cases, the anterior, or front, limbs attach to the pectoral girdle, and the posterior, or rear, limbs connect with the pelvic girdle. The limbs of all mammals have similar bone groupings and structural divisions. Limb usage can vary greatly, however. The front and back limbs of the same animal are often quite different, depending on how they're used. The front limb groupings (see Figures 4.2 and 4.3) include the nails, the front feet, the front legs, and the pectoral girdle. The front < previous page

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Figure 4.1. specialization required by bats for flying, by humans for grasping, and by horses for running. < previous page

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Figure 4.2. Contrasted front limb structural groupings from a dog and a cow. < previous page

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Figure 4.3. A comparison of front limb structures of a dog, a pig, a horse, and a cow. limbs tend to be used for a wider variety of functions than the hind limbs, such as handling food, digging, climbing, or flying. In hoofed mammals such as deer, cows, horses, and pigs, however, the front limbs are used in conjunction with and perform nearly identical functions as the rear limbs when walking or running. The back limb grouping (see Figures 4.4 and 4.5) consists of the claws, back feet, back legs, and pelvic girdle, or hip. Hind limbs are usually associated with the support and movement of the body. Since the pelvic girdle is firmly anchored to the spinal column, the rear limbs often have much less freedom of movement than the front limbs. < previous page

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Figure 4.4. Contrasted back limb structural groupings of a dog and a cow. < previous page

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Figure 4.5. A comparison of back limb structures of a dog, a pig, a horse, and a cow. Feet The makeup of a mammal's footthe portion of the limb that actually comes in contact with the ground during locomotionprovides information essential for inferential classification. The bone structure of the front and rear legs, along with the type of nails and digits, are important indicators of an animal's environmental lifestyle. Before continuing, it's worth mentioning that the carpal and tarsal bones, which make up, respectively, the front and back ankles of the limbs, have been excluded from discussion in this book. Although there are approximately eight carpal and tarsal bones in each limb, < previous page

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Figure 4.6. Carpal and tarsal bones of a dog and an ox. they are small and difficult to locate among scattered skeletal remains. When found, a nonexpert may find it very difficult to extrapolate environmental lifestyle information from their individual shapes. So that you may recognize their general shapes and position, however, Figure 4.6 illustrates the carpal and tarsal bones of a dog and an ox. < previous page

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Page 105 The Front Foot A mammal's front feet have two major sets of bones: the phalanges and the metacarpals. Phalanges form the digits, or toes. A single digit is made up of a proximal, a middle, and a distal phalanx bone. The front feet of most mammals contain fourteen phalanges. Metacarpals extend from the phalanges back to the carpals, or wrist bones, of the front foot. Most mammals have five metacarpal bones in each front foot.

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Page 106 The Back Foot A mammal's back feet have two major sets of bones that are much like those of the front feet: phalanges and metatarsals. As in the front feet phalanges make up the digits of the back feet. A single digit consists of proximal, middle, and distal phalanx bones. A mammal's back foot, like its front foot, usually contains fourteen phalanges. The metatarsals extend from the phalanges back to the tarsals of the back foot. As in its front feet, most mammals have five metatarsal bones in each back foot. Digits The ease of associating environmental lifestyles with foot structure depends on the number and relative size of toe bones found when collecting. All carnivores, many omnivores, and most small herbivores have five developed toes, sometimes with an opposable toe for climbing, as with the opossum. Large herbivores, such as cows and deer, usually have two major toes, and horses have one. The structural resemblance exhibited between foot bones of small herbivores, carnivores, and omnivores can make it difficult to infer environmental lifestyles based solely on these structures. (See Figure 4.9.) It is much easier to use foot structure to separate large herbivores such as deer and horses from large carnivores and omnivores such as mountain lions, humans, and wolves. Determining whether the metatarsals and metacarpals are fused or unfused is one effective indicator, as is the relative shape of the distal phalanx bones of the digits. The metacarpals and metatarsals in large herbivores, unlike those in carnivores and most omnivores,

are usually fused into what appears to be a single bone. (See Figures 4.7 and 4.8.) In addition, the digits of single- and double-toed foot structures, associated primarily with large herbivores, commonly have wedgeshaped distal phalanx bones. Nevertheless, the omnivorous pig has a similar foot structure and so breaks the rule of two-toed foot structure being unique to herbivores. (See Figure 4.10.) Nails All mammals carry some sort of horny sheath-like structure on the end of every digita nail, a claw, or a hoof, depending on the animal. The nails of the front and back feet of an animal are usually similar, if not identical, but sometimes they can be very different. (See Figure < previous page

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Figure 4.8. A comparison of the front feet of a dog, a pig, a deer, and a horse. 4.11.) The form these structures take can be used to infer the creature's environmental lifestyle. Claws Most carnivores, omnivores, and small herbivores have long, narrow, curved nails called claws. The two predominant claw types, retractable and nonretractable, refer to a claw's capacity for movement independent of the digit. Nonretractable claws are firmly anchored to the distal phalanx and extend outward from it. (See Figure 4.12.) Nonretractable claws are common among omnivores, such as coyotes and raccoons: carnivores, such as weasels and otters; and small herbivores, such as

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Figure 4.9. The foot bones of small herbivores (squirrel and rabbit) compared with small carnivores (weasel and marten) and small omnivores (raccoon and opossum). < previous page

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Figure 4.10. The foot bones of large herbivores (deer and horse) compared with a large carnivore (mountain lion) and large omnivores (human, dog, and pig). Notice the uniquely shaped distal phalanx bones in the digits of the pig and the deer. < previous page

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Figure 4.11. Contrasts in nail shape between the front and back feet of a fox (similar shapes), a beaver (dissimilar shapes), and a deer (similar shapes). Retractable claws are anchored to the distal portion of a digit by flexible muscles and tendons. (See Figure 4.13.) This method of attachment allows claws to be pivoted approximately 180 degrees in a slashing, scythelike motion. Retractable claws may indicate a carnivorous lifestyle and are clearly evident in members of the cat family. Claws come in a wide variety of shapes and sizes. Usually narrow, they can be sharply curved, slightly curved, or relatively flat. (See Figure 4.14.) Sharply curved claws, ideal for catching and holding

prey, are often associated with a carnivorous lifestyle. When moving between the shape ranges of curved to flat, however, lifestyle infer< previous page

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Figure 4.12. The nonretractable claw of a domestic dog.

Figure 4.13. The retractable claw of a house cat. < previous page

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Page 112 ences become muddled. For example, the flat claw shown in illustration k of Figure 4.14 is the front claw of a badgera carnivore. Many omnivores, as can be seen in illustrations eh in Figure 4.14, sport sharply curved to slightly curved claws. This, as seen in illustrations i and j of Figure 4.14, can also be true of small herbivores. Hooves and Nails In some mammalssuch as humansnails may be broad and flat rather than curved. Forms range from a shallow dish shape to a high, thick single hoof to a high double or split hoof. Flat dish-shaped nails are most common among omnivores, such as humans. Hooves are common among large herbivores such as deer, antelope, elk, moose,

Figure 4.14. Examples of common curved claw shapes. < previous page

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Figure 4.15. Examples of the flat nail of a human, the double hoof of a cow and the single hoof of a horse. bison, horses, and cows. Hoofed animals are referred to as ungulates. (See Figure 4.15.) Feet and Locomotion Mammals use three basic modes of locomotion, each related to that portion of the feet that come in contact with the ground during the course of regular movement: unguligrade, digitigrade, and plantigrade. (See Figure 4.16.)

Figure 4.16. The three basic positions of animal feet, usually hind feet, used to define locomotion. < previous page

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Page 114 Unguligrade foot position places weight on the ends of the phalanges and movement uses only the distal phalanx portions, often of only two digits. Large herbivores, such as moose, elk, bison, deer, horses, and cows and omnivores, such as peccaries and pigs, rely on unguligrade locomotion. Digitigrade foot position places weight on the phalanges and movement uses only the digits. Most carnivores, such as cats; omnivores, such as dogs; and small herbivores, such as mice, squirrels, and woodchucks, often rely on digitigrade locomotion. Plantigrade movement places weight on the entire foot, using the phalanges, metacarpals, and metatarsals. Omnivores such as humans and bears use plantigrade locomotion. Although most mammals rely on digitigrade or unguligrade locomotion, some switch between digitigrade and plantigrade locomotion as circumstances warrant. For example, humans use plantigrade motion when walking and running but can quickly switch to digitigrade locomotion when sprinting. Legs The lower to upper-middle portions of an animal's front and back limbs are each composed of three major bones. These bones are organized in nearly identical patterns in both the front and the rear. The Front Leg Three bones compose the front legs: the radius, the ulna, and the humerus. In quadruped mammals, these bones form the primary weight-bearing supports for the front portion of the body. The humerus is the largest of the three leg bones and forms the upper

front leg. The radius and the ulna combine to form the animal's foreleg. The radius is the larger of these two bones. (See Figures 4.174.22.) In mammals, the humerus always remains separate, while the radius and the ulna are sometimes fused together. When the radius and ulna have either fully or partially grown together, they are said to be fused. This arrangement, although severely limiting an animal's ability to rotate its foreleg, creates a solid form that provides a secure foundation for primarily unguligrade movement. (See Figure 4.23.) In contrast, when the radius and ulna are completely separate and connected by ligaments in an unfused arrangement, an animal is able to freely rotate its foreleg, greatly enhancing its flexibility during digitigrade and plantigrade movement. (See Figure 4.24.) < previous page

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Figure 4.17. The front leg bones of a human. Length: humerus (30 cm), radius and ulna (25 cm). < previous page

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Figure 4.18. The front leg bones of a bear. Length: humerus (29 cm), radius and ulna (27. 5 cm). < previous page

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Figure 4.19. The front leg bones of a lynx. Length: humerus (14.5 cm), radius and ulna (15.1 cm). < previous page

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Figure 4.20. The front leg bones of a dog. Length: humerus (17.4 cm), radius and ulna (21 cm). < previous page

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Figure 4.21. The front leg bones of an opossum. Length: humerus (7 cm), radius and ulna (9 cm). < previous page

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Figure 4.22. The front leg bones of a deer. Length: humerus (17.3 cm), radius and ulna (24.2 cm). < previous page

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Figure 4.23. The fused radius and ulna of a horse and an ox. < previous page

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Figure 4.24. The unfused radius and ulna of a human and a dog. < previous page

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Page 123 Large herbivores, such as deer, horses, and bison, and some omnivores, such as pigs and peccaries, have fused or semifused foreleg bones. In most carnivores, omnivores, and smaller herbivores, the radius and ulna are usually unfused. Therefore, it can be difficult to differentiate between the front leg bones of small herbivores and those of small carnivores and omnivores. The Back Leg The relationship among bones in the back leg is nearly identical to that in the front leg. The rear leg consists of three bones: the fibula, the tibia, and the femur. The femur is the largest of the three rear leg bones and forms the thigh, or upper back leg. The tibia and the fibula combine to form the lower back leg. The tibia is the larger of these two bones. (See Figure 4.254.30.) The bones of the back leg are organized much like those of the front leg: the femur, like the humerus in the foreleg, is always separate, while the fibula and tibia, like the radius and ulna, can be either fused or unfused. Fused back legs are usually stronger, while unfused limbs are more flexible. (See Figures 4.31 and 4.32.) Weight Estimation What can be inferred from the size of leg bones beyond the basic observation that large animals have large leg bones and small animals have small leg bones? Leg bones of large animals, such as a horse, must thicken disproportionately to provide the same relative strength as the slender leg bones of a small creature such as a weasel.

Simply by growing larger, an animal will suffer a continued decrease in relative surface area when its shape remains unchanged. In this situation, an animal's volume increases as the cube of length (length x length x length), while its surface increases as the square of length (length x length). This means that as an animal grows and maintains the same relative shape, such as a newborn colt developing into an adult horse, its volume will increase more rapidly than its surface area. This increase in volume usually translates into an increase in weight. As an animal's weight increases, so does the cross-sectional area of its leg bones. By measuring or calculating the diameter of femur and/or humerus leg bones at their narrowest point, a mammal's weight may be estimated. (See Table 4.1.) < previous page

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Figure 4.25. The back leg bones of a human. Length: femur (46.6 cm), fibula and tibia (34.6 cm). < previous page

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Figure 4.26. The back leg bones of a bear. Length: femur (33 cm), tibia and fibula (25 cm). < previous page

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Figure 4.27. The back leg bones of a lynx. Length: femur (17 cm), fibula and tibia (17.3 cm). < previous page

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Figure 4.28. The back leg bones of a dog. Length: femur (19 cm), fibula and tibia (19.5 cm). < previous page

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Figure 4.29. The back leg bones of an opossum. Length: femur (8.5 cm), fibula and tibia (8.9 cm). < previous page

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Figure 4.30. The back leg bones of a deer. Length: femur (23.2 cm), fibula and tibia (26.4 cm). < previous page

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Figure 4.31. The fused fibula and tibia of a horse and an ox. < previous page

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Figure 4. 32. The unfused fibula and tibia of a human and a dog. < previous page

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Page 132 Measurements of bone diameter can be made with outside calipers, a measuring device with two thick legs, or jaws, that can be adjusted to determine thickness, diameter, and distances between surfaces. If you don't have access to such instruments, you can use a cloth or vinyl tape measure to determine the circumference of the bone and then calculate its diameter. The equation for calculating diameter from circumference is this: C + Pi = D, where C is circumference, Pi is the constant 3.14, and D is diameter. For example, if a bone's measured circumference is 4 inches, then the bone's diameter would be: 4 + 3.14 = D, where D = 1. 27 inches. In North America, there exists more diversity among large herbivores than omnivores and carnivores of similar bulk. Larger mammals, such as elk, moose, deer, antelope, sheep, horses, and cows are predominantly herbivores, with large, less numerous omnivores, such as bears, and carnivores, such as mountain lions, coming in a distant second. This relationship is also true in smaller mammals. In North America and probably the world, there exists greater diversity among small herbivores than any other type of mammal. Pectoral Girdle The pectoral girdle is anchored to the sternum (or breastbone), vertebral column, and ribs by muscles. This shoulder girdle provides the power and foundation for the articulation, or movement, of each front limb. The primary components of this structure are two clavicles and scapulas, one for each front limb.

(See Figure 4.33.) Also called collarbones, clavicles link the sternum with the scapulas. Small or nonexistent on many running mammals such as deer, these bones are much more developed in burrowing animals such as badgers and climbing animals such as raccoons and opossums. Members of the cat family have very small clavicles that lie loose in the flesh between the scapula and sternum. Clavicles are generally difficult to find in the field because of scavengers, weathering, and general deterioration. For this reason, they will not be addressed further in this chapter. Scapulas, also known as shoulder blades, form the principal structure of the pectoral girdle. Large, somewhat flat, often triangular shaped bones, scapulas are the easiest structures of the shoulder girdle to find and identify. < previous page

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Page 133 Bone Estimated TABLE 4.1 Diameter Weight Estimated in Weight Based in Inches Pounds on the Averaged Diameter of Humerus and Fibula 0.1 1.8 0.17 3 0.18 3.3 0.2 3.6 0.3 16 0.39 35 0.43 38 0.49 46.6 0.56 55 0.59 57.7 0.69 160 0.79 265 0.83 280 0.89 340 0.94 450 1.08 575 1.15 697 1.18 705 1.28 825

1.38 1.48 1.57 1.67 1.77 1.87 1.97 2.07 2.17 2.26 2.36

945 1025 1125 1217 1325 1417 1500 1605 1700 1800 1900

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Figure 4.33. The two predominant bones, scapula and clavicle, of a pectoral girdle. The bold areas indicate these structures. Scapula Structure Visual references are often the best tools for describing specific structures and relating their basic terminology. To this end, Figure 4.34 uses a human shoulder blade to illustrate and label the two structural components of a scapula, the acromion process and coracoid process. Both are commonly used for inferential classification. Scapula Shapes Three general shapes are common among the shoulder blades of mammals: isosceles triangle, paddle shaped, and curved edged, or blade shaped. (See Figure 4.35.) No one scapula shape may be

conclusively associated with a specific environmental lifestyle. At best only the fol< previous page

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Figure 4.34. Two scapular structures used for inferential classification. lowing broad generalizations concerning structural relationships can be drawn. Scapulas in large herbivores, such as cows, horses, elk, and deer, are often shaped like a flat isosceles triangle with reduced acromion and coracoid processes. (See Figures 4.364.39.) In smaller herbivores, such as squirrels, woodchucks, and beavers, scapulas are often the general shape of a blunt curved blade or an isosceles triangle. In addition, these structures usually have pronounced acromion and coracoid processes. (See Figures 4.404.44.) Often carnivores and onmivores such as wolverines, bears, and wolves sport paddle- or curved-edged-shaped scapulas with pronounced acromion and coracoid processes. In some omnivores

such as pigs, however, the scapula is isosceles shaped with reduced acromion and coracoid processes. (See Figures 4.454.53.) < previous page

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Figure 4.35. Three common scapular shapes. < previous page

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Figure 4.36. Top and side views of a deer scapula. Length (17 cm), width (9.5 cm). < previous page

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Figure 4.37. Top and side views of an elk scapula. Length (26.5 cm), width (18.5 cm). < previous page

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Figure 4.38. Top and side views of a horse scapula. Length (33.6 cm), width (18.5 cm).

Figure 4.39. Top and side views of a cow scapula. Length (34.3 cm), width (21.5 cm). < previous page

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Figure 4.40. Top and side views of a beaver scapula. Length (12 cm), width (4.2 cm).

Figure 4.41. Top and side views of a pocket gopher scapula. Length (2 cm), width (1.4 cm).

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Figure 4.42. Top and side views of a gray squirrel scapula. Length (3.4 cm), width (1.5 cm).

Figure 4.43. Top and side views of a Wyoming ground squirrel scapula. Length (2.4 cm), width (1.1 cm).

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Figure 4.44. Top and side views of a western meadow mouse scapula. Length (1.1 cm), width (0.3 cm).

Figure 4.45. Top and side views of a wolverine scapula. Length (10.5 cm), width (6.5 cm). < previous page

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Figure 4.46. Top and side views of a lynx scapula. Length (10 cm), width (5.5 cm).

Figure 4.47. Top and side views of a marten scapula. Length (4.5 cm), width (2.8 cm). < previous page

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Figure 4.48. Top and side views of a dog scapula. Length (14 cm), width (8 cm). < previous page

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Figure 4.49. Top and side views of a raccoon scapula. Length (5.7 cm), width (4.5 cm).

Figure 4.50. Top and side views of an opossum scapula. Length (6.5 cm), width (2.9 cm). < previous page

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Figure 4.51. Top and side views of a bear scapula. Length (23 cm), width (16.2 cm). < previous page

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Figure 4.52. Top and side views of a human scapula. Length (19.1 cm), width (15.5 cm). < previous page

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Figure 4.53. Top and side views of a pig scapula. Length (12.5 cm), width (7.7 cm). The Pelvic Girdle The hipbone, or pelvic girdle, forms the foundation of a skeleton by securely anchoring to the sacrum, or base portion of the spine. Unlike the shoulder girdle, this structure moves only when the spine flexes, a firmness that offers support for power and movement by the rest of the skeleton. The connection between the spine and pelvis, also discussed in chapter 5, is illustrated in Figure 4.54. Because the pelvis forms the largest single skeletal structure, it is often found when hunting bones. Although the pelvis has a distinct shape, people sometimes confuse it with a skull. When inverted or viewed from below, a hipbone can look like a skull without its lower jaw and cranium. (See Figure 4.55.)

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Figure 4.54. Two views, front and back, of a human pelvic girdle with the attached sacrum and femurs of the rear limbs. Mexico rancher firmly maintained that he had discovered numerous dinosaur skulls on his property and insisted that the professors come to his farm and inspect them. He indicated his property was littered with them and didn't understand why folks said they were rare. Through perseveranceand the suggestion that he might donate the artifacts to the universitythe farmer persuaded the professors to visit his ranch. Upon examination, they discovered that the rancher owned an impressive collection of cow, horse, and bison hipbones. When informed of his identification error, the farmer, embarrassed, profusely apologized. Basic Pelvic Structures Three basic structures of the pelvic girdle are helpful in inferential classification. These consist of two general structures, the false pelvis and the true pelvis, and a specific anatomical feature, the acetabulum. (See Figure 4.56.)

Also called the greater pelvis, the false pelvis is the broad, flangelike structure of the hip located just before, or above, the true pelvis. The opposing structures that constitute the false pelvis are called ilia. The true pelvis, or lesser pelvis, refers to the bones just behind, or below, the false pelvis. It is composed of two opposing eye-holed structures < previous page

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Figure 4.55. Two views of a cow skull and hipbone. Notice their relative shapes and consider how a hipbone could be misidentified as a skull or portion of a skull. < previous page

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Figure 4.56. Three basic pelvic structures used for inferential classification. < previous page

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Page 152 called ischia. (See Figure 4.56.) Also called the ball-and-socket joint, the acetabulums are the two socketlike structures on the hip that fit the ball of the femur, or thighbone. (See Figure 4.54.) Posture North American land mammals exhibit two basic hip shapes. (See Figure 4.57.) By analyzing the shapes of hipbones you find in the field, you can infer the normal posture of a mammal, either erect or horizontal, which in turn offers a clue as to the animal's usual mode of locomotion. An erect posture implies bipedal, or two-footed, means of locomotion, and a horizontal posture suggests quadrupedal, or fourfooted, movement. An animal's posture can be inferred from the relative position of

Figure 4.57. Posture as related to pelvic structure from a horizontal

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Page 153 the acetabulum, or ball-and-socket joint, on the hip as well as by the construction of the hipbone itself. Although all mammal hips share similar construction, the human hip differs somewhat from this norm, as seen in Figure 4.57. (Also see Figures 4.584.60.) Without a great deal of study and experience in the fields of osteology and mammalogy, it is difficult to infer anything other than posture from a hipbone, and even that can be tricky for the inexperienced collector. For our purposes it will suffice to keep in mind just one generalization: In North America, the only native bipedal animals are humans. This means that all remaining herbivores, carnivores, and omnivores have pelvises constructed for quadrupedal posture. Summary The conclusive assignment of an animal to a specific environmental lifestyle based solely on its limb structures is impossible without a high level of knowledge and expertise. Until they have reached that point, beginners would be wise to limit themselves to making inferences based only on the following five generalizations. When associated with the rest of the skeleton, limb structures can give the collector a fuller view of an animal's environmental lifestyle. Narrow, curved claws are common among omnivores, carnivores, and small herbivores; hooves are common among large herbivores. Digitigrade locomotion is common among herbivores, carnivores, and omnivores; plantigrade locomotion is usually limited to omnivores and some carnivores; and unguligrade locomotion is

predominant among large herbivores. Fused or semifused radius-ulna and fibula-tibia combinations are common among large herbivores and some omnivores, whereas unfused or separated radius-ulna and fibula-tibia bone structures are common among carnivores, omnivores, and small herbivores. Scapula shape varies considerably across environmental lifestyles. An isosceles-shaped scapula is prevalent among large herbivores and unusual among small herbivores. Curved-edged and paddleshaped scapulas are common among carnivores, omnivores, and small herbivores. The hipbones of most North American land mammals reflect their quadrupedal, or four-legged, posture. Human hips differ in structure and indicate bipedal, or two-legged, posture. < previous page

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Figure 4.58. Hip structures of a Wyoming ground squirrel (2.5 cm), a rabbit (4.7 cm), a marten (5.6 cm), a raccoon (8.1 cm), a coyote (9.7 cm), and a wolverine (12.3 cm). The measurements refer to pelvis length. < previous page

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Figure 4.59. Hip structures of a wolf (18.4 cm), a mountain lion (21 cm), and a deer (25 cm). The measurements refer to pelvis length. < previous page

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Figure 4.60. Hip structures of a bear (30 cm), a horse (35.8 cm), and a human (17 cm). The measurements refer to pelvis length. < previous page

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Page 157 Chapter 5 The Vertebral Column and Ribs An animal's vertebral column and ribs make up its skeleton's supporting framework. These structures alone usually will not provide the nonexpert with enough information to identify the animal's environmental lifestyle. However, through their size and shape these bones can give clues to an animal's posture and relative flexibility during movement.(See Figure 5.1.) The Vertebral Column The vertebral column, or spine, shields the primary nerve conduit to the brain, called the spinal cord, and supports the body. A mammal's spinal column contains individual bones called vertebraeseventeen to sixty or more, depending on the species. The vertebrae are kept from rubbing against each other by bony caps and cartilaginous disks. Basic Structures of a Vertebra Vertebrae vary somewhat in shape according to their location in the spinal column, but all vertebrae share six basic structures. (See Figure 5.2.) Each vertebra has an opening in its center called the vertebral foramen, through which the spinal cord passes. The primary mass of bone

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Figure 5.1. This portion of a dog skeleton demarcates the vertebral column/rib function group. that makes up the vertebra is located below the vertebral foramen and is called the body.The structure that projects vertically from the dorsal, or back, portion of a vertebra is known as the spinous process.Its size and shape vary, depending on the spinal region occupied by a vertebra. Transverse processes are the structures that project laterally from either side of a vertebra. Like the spinous process, their size and shape vary, according to the vertebra's location in the spinal column. Articular processes are located at opposite ends of a vertebra. The inferior articular process, facing up on one end, and the superior articular process, facing down on the other, overlap with their opposite counterparts, up to down and down to up, on following and preceding vertebra. This overlap, illustrated in Figure 5.3, provides connecting surfaces and allows movement between vertebrae. Vertebral Division Structures Within the vertebral column, individual vertebrae are separated by two structures: the intervertebral disk and the vertebral cap, which aid the smooth functioning and flexibility of the spine. Intervertebral disks are relatively thick, cartilaginous structures that function as padding and shock absorbers between vertebrae. When an animal dies and its skeleton decays, the disks dry out. These are often found among the remains of large mammals such as deer, elk, and < previous page

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Figure 5.2. The six basic structures of a vertebra. < previous page

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Figure 5.3. The overlapping and movable connections of inferior and superior articular processes.

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Page 161 cougars but can be difficult to locate among the remains of smaller mammals. (See Figure 5.4.) Vertebral caps are affixed to the ends of the vertebrae and provide a smooth surface between the vertebrae and intervertebral disks. As a skeleton decays, these soft bony caps dry out and often fall off. Like intervertebral disks, caps are easily found among the remains of large mammals but can be difficult to locate among the remains of smaller mammals. (See Figure 5.5.) Spinal Regions The vertebral columns of mammals are typically divided into cervical, thoracic, lumbar, sacral, and caudal regions. (See Figure 5.6.) Mammal spines typically contain seven cervical vertebrae, which extend from the base of a skull to the first rib. Some mammals, such as sloths and anteaters, however, have six or nine cervical vertebrae. (See Figure 5.7.)

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Figure 5.6. Approximate positions of cervical, thoracic, lumbar, sacral, and caudal regions within the vertebral column of a human and a dog. < previous page

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Figure 5.7. Cervical vertebrae from a human and a cow. Not all cervical vertebrae are similar in shape. The first cervical vertebra that follows the skull is called the atlas, and the second, the axis.These vertebrae have unique shapes, quite different from the rest of the cervical vertebrae. (See Figure 5.8.)

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Page 164 Immediately following the cervical vertebrae, the thoracic vertebrae compose the structures that bear the ribs. Depending on the mammal, there can be from nine to twenty-five of these vertebrae. Their often large spinous processes indicate the attachment of welldeveloped shoulder muscles, such as the trapezius. (See Figure 5.9.) Lumbar vertebrae immediately follow the thoracic vertebrae in the spinal column; most North American land mammals have between four and seven. This range should not be considered a global constant, however, since other mammals such as whales have as many as twenty-five and some anteaters have as few as two. The relatively large transverse processes of these vertebrae indicate attachment and support of well-developed back muscles such as the latissimus dorsi. (See Figure 5.10.) Following the lumbar vertebrae, sacral vertebrae normally fuse into a composite structure called the sacrum.As shown in Figures 4.54 and

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Figure 5.10. A lumbar vertebra of a cow. Notice the unique wing shape caused by a large transverse process. 4.57 of chapter 4, this solid arrangement of vertebrae attaches firmly to the pelvic girdle along a portion of the ilium. (See Figure 5.11.) Caudal vertebrae make up the tail of a mammal; how many an animal has depends on the length of its tail. For example, a mountain lion has a long tail and therefore many caudal vertebrae, but a bobcat's tail is very short and thus has only a few. Humans, who have vestigial tails, have no developed caudal vertebrae. (See Figure 5.12.) Spinal Curvature Because the spine is held together by cartilage, which decays rather quickly, it is unusual to find an intact vertebral column among animal remains. Even if it is still intact, it is likely to be twisted into an unnatural position. It's more common to find the vertebrae separated and scattered about. In either case, it's difficult for a nonexpert to accurately determine a spine's original shape. Fortunately, we can learn much about spinal shape by observing

living mammals. When any animal moves quickly, its spine contracts, flexing toward the back as the animal moves its hind feet forward and curving toward the abdomen when it stretches out, moving its hind feet backward. Often, the greater the upward curvature in the spine when an animal is standing still, the greater the flexibility in the spine when it moves. The spines of living North American land mammals may be categorized into three basic shapes: humped-back, flat, and double-curved. < previous page

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Figure 5.11. Two views of sacra of a horse and a dog. Parallel holes within these structures mark vestigial remains of spaces between individual vertebrae lost when the sacral vertebrae fused. < previous page

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Figure 5.12. Caudal vertebrae of a cow. Notice the unique shape of these structures when compared with other vertebrae.

Figure 5.13. Three shapes of spinal curves and their postural orientation. Humped-back Spines A spinal column whose lumbar and thoracic regions exhibit an upwardly curved shape is said to be humped-back. This formation of the vertebrae allows for the spine to act like a spring, resulting in greater running or climbing speed. (See Figures 5.14 and 5.15.) This shape is prevalent among carnivores, omnivores, and

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Figure 5.14. The flexibility of a rabbit's humped-back spine while running. Movement ranges through the spinal positions: stationary, contracted flexing up, and reverse-flexed. arch. This flexibility affords greater power and distance in stride. Cat spines also have whiplike flexibility, allowing the felines to run and climb quickly and jump great distances both vertically and horizontally. The hump in a weasel's spine is what allows its characteristic ''slinking" movement. < previous page

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Figure 5.15. The flexibility of a cat's humped-back spine while running. Movement ranges through the spinal positions: stationary, contracted flexing up, and reverse-flexed. Raccoons always look as if they are walking on their toes, not only because they are, but also because of their upwardly arched spine. This feature greatly enhances their climbing ability. And, of course, who has not seen the back-arching profile of a greyhound? Built for speed, these dogs are raced at tracks across the United States. In every situation, a humped-back spine increases an animal's potential for fast takeoffs, quick bursts of speed, and, for those adapted to it, enhanced climbing and jumping ability. This is advantageous for hunter and prey alike.

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Page 170 Flat Spines In flat-spined animals, the lumbar and thoracic regions of the spinal columns may be flat or very slightly humped. This construction often reduces a spine's flexibility and so limits an animal's speed and mobility when running. (See Figure 5.16.) The spines of large herbivores such as horses, cows, bison, and moose are flat when standing, although a horse's spine will often exhibit a slight upward arch. These animals' spines flex between slightly humped and slightly concave when they run, limiting their stride power and distance. A flat-spine construction does not mean an animal cannot move quickly, however. Anyone who has seen a stampede knows that cows and bison can run fast, and the horse's potential for speed is evidenced every year at the Kentucky Derby. Like juggernauts slowly building up straight-line motion until traveling at a relatively good clip, a flat spine offers long-term speed, usually at the expense of quick takeoffs and agility. Double-curved Spines A spinal column whose thoracic region bows out while the lumbar region bows inward is called double-curved. As with a flat spine this construction limits an animal's running speed by reducing its springlike flexibility. (See Figure 5.17.) In quadrupeds, a double-curved spine is debilitating, either the result of a birth defect or due to the wear and tear of old age. This shape can also be the result of affliction, as in swaybacked horses, whose

spines have become deformed by carrying too much weight for extended periods of time. For bipeds, however, this spinal construction affords a balanced, inline structure for upright posture and is indicative of only one North American land mammal, the human. Although this spine shape limits potential speed to some degree, it does compensate its upright bearer with an increased potential for mobility and agility. Vertebral Inferences As mentioned earlier, it can be difficult for the inexperienced collector to infer environmental lifestyles from vertebrae alone. So just what can be learned from them? When cervical vertebrae are the same size as or larger than lumbar and sacral vertebrae from the same skeletal remains, such as in < previous page

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Figure 5.16. The flexibility of a horse's flat spine while running. Movement ranges through the spinal positions: stationary, contracted flexing up, and reverse-flexed. < previous page

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Figure 5.17. The flexibility of a human's double-curved spine while moving. Movement ranges through the spinal positions: stationary, contracted flexing up, and reverse-flexed. cows and deer, the neck is usually relatively long. This arrangement requires long, strong muscles to hold both the skull and the neck upright, implying quadrupedal, or four-footed, posture.* (See Figure 5.18.) When the cervical vertebrae are the same size as or smaller than lumbar and sacral vertebrae, the neck is often relatively short. A short *This generalization works only with large mammals. In smaller mammals, there often appears less difference in the relative sizes among vertebrae.

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Figure 5.18. Long necks of a horse and a cow as indicated by cervical ertebrae that are larger than vertebrae from other spinal regions of the same animal. < previous page

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Page 174 neck, as in humans, requires smallerthough still strongmuscles to hold both skull and neck upright, implying bipedal posture. Thoracic vertebrae often have spinous processes much larger and sharper than the spinous processes on vertebrae from other spinal regions. These vertical structures offer ideal support and attachment points for large shoulder muscles such as the trapezius and rhomboideus, which anchor along this spinal region and provide the primary strength for movement of the front limbs. Large spinous processes imply large shoulder muscles such as the trapezius and rhomboideus, which anchor along this spinal region and provide the primary strength for movement of the front limbs. Unlike other vertebrae that make up the spinal column, lumbar vertebrae sport large transverse processes. These lateral, or horizontal, surfaces offer ideal support for long, large back muscles such as the latissimus dorsi, which run along the back and provide the main strength and support for movement within this area. As with the spinous processes of the thoracic vertebrae, large transverse processes suggest large back muscles and are common developments among all mammals, especially large herbivores. The Ribs Ribs attach to the thoracic vertebrae and sternum, or breastbone, forming a cagelike structure called the thorax, or rib cage. The number of ribs varies with the species. For example, the rib cages of humans and domestic dogs contain approximately twenty-four ribs, whereas a horse has approximately thirty-six. The space between ribs is called the intercostal space, and the cartilage that connects

ribs to the sternum is called costa cartilage. The rib cage protects the heart and lungs and provides a semivacuum chamber necessary for the proper functioning of the lungs. Flexible rib connections at spine and sternum allow the rib cage to expand and contract during breathing. It is difficult to infer environmental lifestyle from rib structure alone. What inference may be made by beginning collectors relies solely upon rib size and relative degrees of rib curvature. This does not mean rib structure and shape can be ignored. Rather, collectors, so as not to confuse ribs with other bones, will find such knowledge < previous page

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Page 175 essential. The following story illustrates the importance of this information and how a person, through lack or disuse of this knowledge, can make mistakes with ribs. I once collected cow bones with a man who had a degree in natural resource conservation, a field of study that incorporates mammal comparative structural anatomy. As we rooted through autumn leaves, gathering and placing bones in small piles, he mistakenly identified one of the first vertebrosternal ribs, discussed below, as a leg bone. When I corrected him he was greatly embarrassed and confided that he had not used his education for over fifteen years. Since then this person has reeducated himself in comparative anatomy and now uses this information as a regular hobby. Basic Rib Structures Ribs, regardless of their position within a rib cage, exhibit four basic features: head, tubercle, neck, and body, or shaft. (See Figure 5.19.) The lower portion at the spinal end of a rib that attaches between two vertebrae is called the head. This is the primary attachment point of a rib to the spinal column. The rib structure adjacent to the rib head that attaches to a vertebra is known as a tubercle. This is the secondary attachment point of a rib to the spinal column. The portion of a rib located between the head and tubercle is called the neck. Also called the shaft, the body curves away from the head and tubercle to form the major structure of a rib. The end of the body, opposite the head and tubercle end, attaches via a cartilage extension, costa cartilage, to the sternum. Not all ribs attach at both

ends. For example the floating ribs, discussed later, connect only to the vertebrae. (See Figure 5.20.) Rib Arrangement In mammals, the rib cage can be divided into two basic groupings: true ribs and false ribs. Also called vertebrosternal ribs, true ribs extend and attach along the thoracic region of the spine, anchoring to the sternum and ending at its base. False ribs include the vertebrochondral ribs and the vertebral, or floating, ribs. Starting from a location below and roughly parallel to the base of the sternum, vertebrochondral ribs, which are similar in appearance to the true ribs, extend from and anchor along the remain< previous page

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Figure 5.19. The four structural components of a rib important in inferential classification. < previous page

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Page 177 ing portion of the spine's thoracic region and attach via cartilage to the bottom of the sternum. Immediately following the vertebrochondral ribs, the vertebral ribs attach only to the final thoracic vertebra. (See Figure 5.20.) Lifestyle Inferences As stated at the beginning of this chapter, using ribs to infer environmental lifestyles can be difficult without extensive study in this field. Nevertheless, beginning collectors may use two general rules of thumbrelated to rib size and rib curvatureto garner useful information. Rib Size Larger rib bones mean larger animals and smaller rib bones mean smaller animals. In North America most large mammals such as deer,

Figure 5.20.

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Page 178 cows, bison, elk, horses, and moose are herbivores. (However, large carnivores and omnivores, such as bears and humans, also exist.) Statistically there are more large herbivores than large carnivores and omnivores, so collectors often associate large ribs found alone in the wild with herbivores. When ribs are found alone, a collector without proper anatomical awareness of rib shape and construction can confuse rib classes across species. For example, a floating rib from a large mammal may be confused with a vertebrochondral rib of a medium-sized mammal. For this reason, a collector may find the ability to discern between various rib types an important skill. This is best performed by recognizing the patterns associated with the head, neck, and tubercles of the three basic rib types. (See Figure 5.21.)

Figure 5.21. Example transformation in relative shapes in rib head, neck, and tubercle structures when progressing from vertebrosternal to vertebrochondral to vertebral, or floating, ribs in a cow. (The progression starts at the upper left of the illustration and ends at the lower right.) < previous page

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Page 179 Rib Curvature Generally, rib curvature increases with body mass, producing relative variation in rib cage shape. Often, the larger the mammal, the greater the apparent barrel shape of its chest. Please note, however, that without the presence of the costa cartilage that connects ribs with the sternum, actual chest shape is difficult to determine. With this in mind, the following broad associations of chest shape with body mass, including exceptions, can be made, but keep in mind that without a great deal of experience, collectors will find rib curvature to be an inadequate tool for inferential classification. Large mammals, such as horses, bears, and cows, often sport round to downward-pointing ovular chests. Intermediate-sized mammals, such as deer, appear to have narrower, slightly pointed chests. Pigs have seemingly barrel-shaped chests, however, and humans have elliptical, flattened chests. Smaller mammals, such as mice, chipmunks, weasels, and opossums, have round chests flattened slightly along the breast. Rib shape can also be used to infer a mammal's posture. All mammals in North America, except for humans, are quadrupedal. The curved or slightly curved ribs of most mammals that imply, as with horses and deer, rounded and pointed chest shapes also suggest a quadrupedal posture. The sharply curved ribs associated with a human skeleton imply a flat chest and bipedal posture.

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Page 180 Chapter 6 The Significance of Skeletal Structures From the skeletal structure of an animal you can learn much about its probable behavior and habitat. Each structure in a skeletal system serves a unique purpose and influences the shape, size, and positioning of every other. For example, the size and shape of the nasal cavity will affect the dimensions of the maxilla, or upper jaw. These combined structures in turn determine the relative size of the lower jaw and the positioning of the eye sockets. By evaluating these interrelated structures as a whole, it's possible to infer environmental lifestyles. Carnivores are almost always considered hunters that stalk, attack, and kill their prey. As such, this lifestyle embodies an aggressive attitude that is reflected in their skeletal features. However, many carnivores are also scavengers, and while they may be more cautious than their strictly hunting brethren, they too are considered aggressive. Since plants don't usually threaten bodily harm and require little stalking prowess on the part of their consumer, herbivores are considered primarily passive and defense oriented. Reflecting this behavior, the skeletal features associated with this lifestyle exhibit adaptations optimized for running, motion sensing, and consuming plants. Omnivores consume animal flesh and plant material. Their behavior, as reflected through this diet and skeletal structures, ranges

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Page 181 between the aggressive, attack-oriented behavior of a carnivorous lifestyle and the passive, defense-oriented behavior of a herbivorous lifestyle. You should keep in mind, however, that although an animal's skeletal construction may indicate certain behavioral tendencies, most creatures can adapt their behavior to some degree if their survival requires it. For example, rats are rodents and therefore herbivores, but they have been known to attack other creatures without provocation when plant food was scarce. With this in mind, let's begin our discussion of how skeletal structure relates to behavior and habitat. Please note, however, that the interpretations presented in this chapter reflect the author's knowledge, perspective, and opinions. They should not be considered absolute guidelines, as behavior and habitat vary greatly among individuals. Readers are urged to incorporate personal knowledge and perspective with the material presented in this book to develop their own interpretations. Carnivores In many ecosystems, animal flesh provides the single most concentrated source of food. Since it consists largely of proteins and water, this nourishment is heavy and slow to digest. For this reason, and because they tend to gorge themselves, carnivores are often sluggish after eating. Though proficient at both, carnivores generally prove more adept at offense than defense. Since prey animals often run or put up a fight,

carnivores can expend enormous amounts of energy in pursuit and capture. Since a carnivore can also be prey for other animals, however, it must be able to run or in some other way protect itself from being eaten. The form of skeletal structures such as orbits, dentition, the zygomatic arch, and limbs are designed to function in both the attack and defense modes common to hunting and scavenging lifestyles. The following profiles discuss these structures in three carnivores: the domestic cat, the badger, and the bat. Profile of a Domestic Cat In the area of south-central New York where I grew up, a large cat population was partly responsible for the demise of songbirds, squirrels, rabbits, and other small mammals. Domestic cats released in the < previous page

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Page 182 wild must revert to their hunting heritage to survive. I've seen feral cats, their lithe supple bodies slinking through the grass and brush, effortlessly leaping between tree branches in play and pursuit of prey. As efficient predators, domestic cats, like their wild cousins, are built for hunting, catching, and devouring prey. Enamored as we are of their playful stalking, furniture-leaping, and string-swatting, many of us fail to recognize the aggressive hunting behavior reflected by these actions. (See Figure 6.1.) A cat's orbits face somewhat forward. (See Figure 3.1 in chapter 3.) This position, while providing the animal with binocular vision and depth perception, allows excellent peripheral vision, essential for hunting, targeting, and ambushing prey. Cat dentition, as shown in Figure 2.4 in chapter 2, includes narrow incisors, long canines, prominent bicuspids, and sharply serrated carnassials, or molars. This construction allows the cat to eat by gripping prey with the front teeth and, with a tug of the head, tear off chunks of flesh. Chewing and cutting are performed by the carnassials. The short, blunt shape of a cat's nasal cavity is mirrored by a short, slightly curved mandible. Prominent zygomatic arches house large, well-developed temporalis muscles that attach along an oftenprojecting sagittal crest. Together, these structures indicate that a cat kills by gripping prey and crushing it with its jaws. Cats have sharply curved, retractable claws, meant for aggressive

gripping and slashing during both attack and defense. The ability to hook and dig into an object also implies the claws' possible employment for climbing. Also implying ground-based or arboreal habitat is the cat's five-toed foot, an indicator of digitigrade locomotion. (See Figures 4.14 and 4.15 in chapter 4.) In cats, the bones of the lower front legsthe radius and ulnaand the lower back legsthe fibula and tibiaare unfused, also indicating ground-based or arboreal habitat. Allowing relative freedom of limb flexibility, this bone association permits agility when running, walking, or climbing over uneven terrain. Profile of a Badger During one of my frequent backcountry sojourns, I encountered a mountain park ranger in the course of his rounds. As we passed the time of day, the conversation turned toward natural events we had < previous page

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Figure 6.1. A cat skeleton. witnessed. After a slight pause, he related the tale of a confrontation between a badger and a bear. He had first spotted the grizzly sauntering along the wooded edge of an open field fifty yards upwind from where he stood. Remaining motionless, the ranger watched through field glasses as the bear stopped to investigate a creature that was burrowing frantically in the loamy soil. After giving the other animal an imperious nudge with its foot, the bear quickly retreated from the snarling fury that charged from the shallow hole. Even at that distance the ranger recognized the badger's telltale face stripes. Once the bear had withdrawn a sufficient distance, the badger returned to its digging. Again the bear advanced; this time it nudged the badger with its muzzle. The badger turned in a frenzy and clamped its teeth into the bear's nose. Startled, the bear reared into

the air and stood for a moment on its hind legs, the badger dangling from its face. Then with a roar it shredded the little creature and retreated, nose streaming blood, but otherwise intact. < previous page

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Page 184 Stripe-faced and burrowing, wild badgers are known for their single-minded pursuit of prey and bad temper when interrupted. Because of their combative and belligerent nature, few creatures bother them. When kept as pets, badgers, though relatively docile, tend to be aggressively intolerant of abuse. Interpretation of badger skeletal structures indicates that they exhibit strong aggressive behavior toward their prey and vigorous attack-oriented defensive behavior when confronted by predators. Leg, foot, and claw structures imply a ground-based habitat, with burrowing ability important to survival Development in orbits, teeth, and jaws suggest that they are carnivores. (See Figure 6.2.) As is common to many carnivores, badger orbits face somewhat forward, so the animal has limited binocular vision but excellent peripheral vision. This visual acuity is essential for active hunting. Badger dentition consists of narrow incisors, long canines, sharp bicuspids, and serrated molars. This structure suggests that the animal grips and tears with its front teeth while chewing and cutting with its side teeth.

Figure 6.2.

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Page 185 The relatively long nasal cavity of a badger's skull reflects the shape of its upper and lower jaws. Longer jaws mean that less power is transmitted to their forward positions, so they have a weaker grip. This is why small carnivores with long muzzles cannot effectively kill large prey by gripping it with their jaws; instead they nip and slash. Smaller prey do quickly succumb to this crushing power, however. The long, slightly curved, spadelike claws on a badger's front feet, as shown in Figure 4.14 of chapter 4, are designed for digging rather than slashing or gripping, implying a ground-based habitat. The badger's five-toed foot structure indicates digitigrade locomotion, and its leg bones are unfused, allowing it agility when running and walking over uneven terrain. Both of these features add to the case for a ground-based habitat. Profile of a Bat When I was a child, bats were a mystery. During the day squeaks and chitters emanated from underneath age-bulged shingles that covered the sides of the old farmhouse in which I grew up. I had never seen a bat except in flight, and that was only an erratic silhouette at dusk. Curiosity engaged my seven-year-old mind and I became determined to observe one at close range. I had heard stories of people night-fishing for bats, a pastime that reveals much about the human psyche. The procedure was simple: You tied a small bit of cloth to a fishing line and cast it into a bat's flight path. Bats that took the lure were played like fish and finally grounded with a sharp tug. After attempting this without success, I

hit upon another method. Common wisdom of the day considered bats to be carriers of rabies. So, hands protected by heavy gloves, I used a garden hose to wash an unlucky individual from its resting place beneath a shingle. I caught the waterlogged bat as it fell to the ground, being careful not to tear its delicate wing membranes. Its open mouth emitted a silent stream of high-pitched squeals, and flashed an array of sharp white teeth. With black beady eyes staring straight ahead, the struggling bat frantically twisted its leathery wings. It never once attempted to bite, only to escape. < previous page

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Page 186 Slowly I began to understand that I was terrifying and torturing the creature, so I released it. The bat flew back to the house, swayed a moment, and then, using its wings and back legs, climbed into the shelter of an overhanging shingle. Some people call them flying rats or mice with wings. Emerging at dusk from their resting places, they careen through night skies seeking insect prey.* This nocturnal hunt requires keen perception and an erratic flying pattern to match that of their prey. By examining a bat's skeletal structures, we can infer that bats exhibit aggressive behavior toward their prey but are relatively passive with other creatures. The structures of their legs and feet indicate an aerial lifestyle with a primarily arboreal habitat when resting. The form of their dentition, jaws, and claws implies that they are insectivorous. (See Figure 6.3.) Although bats depend primarily on their sense of hearing to locate objects and maneuver through space, they do have functional eyes. As with many carnivores, a bat's skull orbits, as seen in Figures 3.13 and 3.14 of chapter 3, are rotated facing forward. This orientation, when the eyes are actively used, provides binocular vision and depth perception. As is common among insectivores, bats sport undifferentiated dentition in the form of pointed incisors, long canines, and sharp symmetrical molars. This structure suggests that bats grip and tear with their teeth but don't really chew their food. There are many families of bats, each exhibiting unique body sizes

and skull shapes. Among these groups nasal cavities may be long with long mandibles or short with short mandibles. However, regardless of relative jaw size, all bats kill their prey by gripping and crushing it with their jaws. Bats usually have one curved claw on each front limb that extends from a thumblike digit on the wing. Like the claws present on the back feet, they are used for climbing and gripping. These structures imply an arboreal habitat, while their rather limited use argues for passive, defense-oriented behavior when the animal is threatened. Bats have distinctive foot structures. The presence and orientation *Not all bats are insectivorous. For example, large fruit batscalled ''flying foxes"that live in the South Pacific and Indonesia are herbivores. < previous page

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Figure 6.3. A bat skeleton. of elongated digits on their front limbs strongly suggest that they have wingsand of course, we know that they do. Naturally, the presence of wings suggests an aerial lifestyle and an arboreal habitat. As with most small mammals, the bones of the lower front legs and back legs of bats are unfused, a feature that enhances their agility and flying ability.

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Page 188 Herbivores All herbivores have flat, well-developed molars, although many appear to be missing canines and bicuspids. Herbivores are divided into three categories based on their dentition, particularly incisor development: perissodactyl, ruminant, and rodent. In most ecosystems, plant food is easy to come by and consists largely of cellulose and water. Because these products have little or no food value, herbivores eat more and do so more often than other animals. Since plants do not run or put up a fight, herbivores tend to be more adept in defense than in offense. This tendency is reflected in skeletal structures that help herbivores protect themselves from predators. The implications of specific bone formations are discussed below for representatives of each herbivore category. Profile of a Horse Ridden for pleasure, sport, and work, domesticated horses have toiled for thousands of years as beasts of burden. As grazing animals they are usually passive, but they can become quite aggressive when threatened, kicking and biting in defense. Their leg, foot, and hoof structures indicate a relatively level ground-based habitat, and the form of their orbits, teeth, and jaws strongly suggests a herbivorous lifestyle. (See Figure 6.4.) As illustrated in Figure 2.8 in chapter 2, the wide, well-developed incisors in a horse's upper and lower jaws prove ideal for cropping plants evenly. There is a full complement of large, flat molars,

which serve as excellent structures for grinding plant material. The presence of these dental structures and the absence of teeth capable of slashing and tearing (i.e., canines, bicuspids, and carnassials) indicates passive, defense-oriented behavior. A horse's orbits, as seen in Figure 3.30 in chapter 3, are angled slightly forward while facing out from the skull. This orientation produces a narrow band of binocular vision directly ahead of the animal and allows excellent peripheral vision. This structure implies an open habitat, such as sparsely wooded areas, open fields, and plains, where spotting movement and possible threats approaching from the sides and rear is essential to survival. Horses have a long, narrow-to-wide nasal cavity and mandible. Their small zygomatic breadth suggests passage of relatively small < previous page

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Figure 6.4. A horse skeleton. temporalis muscles and the presence of strong masseter muscles. This combination allows the horse to maximize pressure at the back of the jaws, where the molars reside, and effectively crush and grind strong plant fibers. As shown in Figure 4.15 in chapter 4, horses have single hooves. The presence of hooves eliminates the possibility of an arboreal habitat. Their broad hooves tend to limit the animal's geographic range to hills and flat, dry areas, but since wide hooves distribute weight over a large area, horses may, in a somewhat limited fashion, negotiate marshy ground. A horse's single-toed foot structure, as shown in Figure 4.8 in chapter 4, implies digitigrade locomotion and a primarily passive running defense.

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Page 190 lower front and back legs are fused. This limits limb flexibility and further indicates a relatively flat ground-based habitat with running and walking the primary means of locomotion. Profile of Cattle and Sheep Although their wild counterparts still roam in limited areas around the globe, most cattle and sheep are domesticated as food animals or, as in the case of oxen, yoked for work. Usually living in open fields and hills, these animals, particularly sheep, are passive. They would rather run from attack than fight. Their leg, foot, and hoof structures provide conclusive proof that they inhabit relatively firm ground. Their herbivorous lifestyle is reflected in the structure of their orbits, teeth, and jaws. (See Figures 6.5 and 6.6.) As illustrated in Figure 2.7 of chapter 2, ruminants such as cattle and sheep have wide, well-developed incisors in the lower jaw only. The absence of incisors in the upper jaw requires plant material to be torn or ripped during grazing and browsing. This process, accomplished with an upward flick of the head, uses the incisors in the

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Page 191 lower jaw as a stationary cutting edge. Absence of incisors in the maxilla as well as dentition capable of slashing and tearing (i.e., canines, bicuspids, and carnassials) implies passive, defenseoriented behavior. Orbital positions among ruminants range between the extremes of facing laterally from the skull, as with cowsproducing strict monocular visionto facing slightly forward, as with sheepproducing limited binocular vision. These positions allow excellent peripheral vision but little if any depth perception. This structure implies an open environment where spotting movement and possible threats approaching from the rear is essential to survival. For example, sheep often live in both open plains and wooded or rocky areas; their eye sockets are rotated slightly forward. Buffalo and longhorned cattle, whose eye sockets face outward from the sides of the skull, live in open plains areas. Cows have long, wide nasal cavities and mandibles, while sheep have long, narrow nasal cavities and mandibles. Their small zygomatic breadth, a distinctive feature of both animals, suggests relatively

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Page 192 small temporalis muscles and strong masseter muscles. As discussed above, this combination allows the animal to exert great pressure at the back of the jaw and crush and grind cellulose with the molars. The flat and/or horned cranium common to large herbivores such as cows indicates that the animal uses its head (literally) for defense. For example, musk oxen form a defensive circle, heads and horns lowered, facing outward to ward off attackers. Goats will butt attackers with their heads and hook them with their horns. Any rodeo rider or bullfighter is familiar with the goring techniques of bulls. Deer and elk will lower their heads when cornered, brandishing their antlers in the face of their attackers. Cattle and sheep sport split hooves. (See Figure 4.15 in chapter 4.) The presence of hooves indicates a ground-based habitat and passive, defense-oriented behavior. Small split hooves, such as those on sheep and deer, indicate firm, dry habitats ranging from plains to mountains. Small-hoofed mammals would find boggy areas uninviting and potentially perilous because narrow hooves focus an animal's weight onto a limited surface area. This severely curtails their traction on soft wet ground and can cause them to quickly sink into bogs and quagmires. Larger hooves, such as those on cows, tend to limit an animal's geographic range to flat or hilly areas. While many large-hoofed mammals may find themselves endangered on boggy ground, large hooves offer an advantage of weight distribution over a greater surface area, allowing them to sink less. For example, the round, splayed hoof of a moose allows it to traverse and navigate wetlands

and waterways that would be inaccessible to small-hoofed mammals such as deer. The two-toed foot structure shared by cows and sheep indicates unguligrade locomotion, further indication of a ground-based habitat. (See Figure 4.8 in chapter 4.) Cows and sheep also have fused lower leg bones, a structure common among large, groundbased herbivores. Profile of a Rabbit The world is so rich that more events occur in a day than I will ever experience in my entire life. Therefore, I listen when people relate their experiences and observations. I once struck up a conversation with a retired dairy farmer who raised rabbits as a hobby. While we shared rabbit stories he told me of a fight he'd seen between a cat and a wild rabbit. < previous page

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Page 193 It was spring, and the rabbit was lounging near its warren, nibbling fresh shoots of grass and plantain. Hunched, tail twitching, a barn cat watched intently from behind a nearby fence post. Expecting an easy meal, it slowly stalked forward while circling to the rabbit's rear. When close enough, it darted forward. The rabbit, sensing the motion, jumped to the side, narrowly avoiding the cat's lunge, and escaped by diving into its warren. The cat broke its charge at the bolt-hole, but after smelling newborn rabbits insidea much easier mealit made as if to enter. The rabbit quickly emerged from her den and confronted the crouched cat. Leaping into the air, she brought both hind feet crashing down upon the cat's head and killed it. A rabbit's legs, while used primarily for hopping and running, can muster a great deal of force. Upon examination by the farmer, the cat was found to have a fractured skull.

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Page 194 This behavior was unusual, prompted by distress and maternal instinct. Rabbits are usually passive and will run rather than fight when confronted by a predator. (See Figure 6.7.) Rabbits and rodents, as illustrated in Figure 2.6 in chapter 2, develop a single pair of long, chisel-shaped incisors in the upper and lower jaws. The shape and construction of these teeth makes gnawing or flaking off pieces of plant material the only sensible procedure for consuming food. Since rodents are the only mammals whose incisors continue to grow throughout their lives, they must continually gnaw to keep the teeth worn down; otherwise the incisors would curve around and grow up through the skull. Rabbit eye sockets are rotated somewhat forward, allowing both binocular vision and peripheral vision. This structure implies that the animal lives in habitats where the view might be obstructed such as in tall grass and wooded areas. In such areas, the ability to judge the distance of objects and spot movement from the rear is essential to survival. Rodents and rabbits share several traits: short-to-long narrow nasal cavities, curved or slightly curved mandibles, and a large zygomatic breadth. Together these structures suggest large, well-developed temporalis muscles and equally developed masseter muscles, thus allowing the animal to exert pressure at the front, side, and rear portions of the jaw. Pressure created by the temporalis at the front of the jaw where the incisors reside provides the power necessary for gnawing strength. The power provided by the masseter muscles helps the animal crush and grind cellulose with its molars. This

combination of structures indicates defensive behavior. Small herbivores often have curved or slightly curved to flat nonretractable claws. (See Figure 4.14 of chapter 4.) When curved, these structures indicate arboreal or ground-based habitats. Flat claws, such as those on rabbits, are fairly conclusive of groundbased habitats. Rabbits have five-toed front feet; long, over-developed back feet and unfused lower front and back leg bones, indicating a grounddwelling habitat, with running and walking as the primary means of travel. Omnivores Omnivores rarely consume equal proportions of plant and animal food. Usually they will eat more of one than the other, depending on < previous page

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Page 195 what's available. In most ecosystems plants are plentiful, providing a consistent source of sustenance. In environments such as deserts where plant life is sparse, animal flesh offers a more reliable and concentrated food source. The ability to consume materials from these divergent sources enhances an animal's survivability by allowing it independence from a single food source. The hunting, foraging, and scavenging of an omnivorous lifestyle generally require an animal to be adept at both offense and defense. Omnivores, like carnivores, can expend great amounts of energy in pursuit and capture of prey. As potential prey, they must be able to run or in some other way protect themselves from being eaten. Skeletal structures such as orbits, dentition, the zygomatic arch, and limbs reflect the defensive and attack behaviors that are both common to an omnivorous lifestyle. Three familiar omnivores are discussed below: the domestic dog, the pig, and the human being. Profile of a Domestic Dog While I was growing up it seemed everyone had dogs. Most were well treated, and their behavior expressed this. When hunting, threatened, on duty protecting, or abused, however, normally tranquil canines could suddenly become aggressive. I once observed a malamute, which I had seen chase deer and catch rabbits, stoically endure the demanding advances of a young boy. Suffering a barrage of tweaked ears, yanked tail, and occasional swats from the child, the dog steadfastly refused to be drawn into play. Ignoring requests by his mother and aunt to leave the dog alone, the frustrated child struck the dog in the eye with a piece of

firewood. Until this point the malamute had remained aloof and indifferent. Once struck, however, he reacted to the pain by biting the boy. Both dog and boy required stitches. The moniker "man's best friend" leaves little doubt as to a dog's status among humans. Domesticated from the same root stock as their wild cousins, dogs have been used through the ages for personal property protection, companionship, and hunting. Since they retain skeletal attributes from their wild predatory/scavenging ancestors, there are people who consider them aggressive. However, while this may be true of some dogs, most exhibit a greater degree of passive than aggressive behavior. (See Figure 6.8.) Dogs have narrow incisors, long canines, prominent bicuspids, < previous page

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Figure 6.8. A dog skeleton. serrated carnassials, and partially developed flat molars. This dentition suggests that the animal kills by gripping and crushing its prey with its front teeth. The dog then tugs its head to tear off chunks of animal flesh and plant material and chews and cuts it with the side teeth or molars. This dental structure, illustrated in Figure 2.10 in chapter 2, can be considered suggestive of strong attack and defensive behaviors. The slight curve of a dog's lower jaw, as shown in Figure 2.16 in chapter 2, allows the animal to use maximum pressure at both the rear and forward portions of the jaws. In the front, where the incisors, canines, and bicuspids reside, this shape provides power for the cutting and tearing of both animal flesh and plant material. In the rear, where the carnassials and molars reside, this structure provides power for cutting flesh as well as crushing and grinding cellulose. This structure, in combination with the teeth, indicates the

offensive and defensive behaviors necessary for a hunting, scavenging, and foraging lifestyle. In canine skulls the orbits usually face somewhat forward, allowing both binocular and peripheral vision. (See Figures 3.35 and 3.36 in < previous page

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Page 197 chapter 3.) Both are necessary for tracking and judging the distance between animals and objects before, during, and after attack. This orbital orientation, when associated with other skull features, implies an aggressive hunting lifestyle and a habitat where the field of vision is open or partially obstructed, such as tall-grass or wooded areas, mountains, hills, and plains. Dogs have a prominent zygomatic arch that allows passage for large well-developed temporalis muscles. When taken into account with the often peaked cranium and slightly curved mandible, these structures imply that the animal eats by gripping and crushing with the forward portion of the jaws. Since plants don't run away or fight back, it can be assumed that this gripping is for live animals, suggesting aggressive offense, rather than passive defense, behavior. The sharp to slightly curved nonretractable claws sported by dogs imply a ground-based habitat where these structures are employed for gripping while running and possibly for digging. (See Figures 4.12 and 4.14 in chapter 4.) A dog's five-toed foot structure, as shown in Figure 4.7 in chapter 4, indicates digitigrade locomotion, and its lower leg bones are unfused. This indicates that the dog lives on the ground and is able to run and walk over uneven terrain. Profile of a Pig Both hunted and raised for meat, these large, primarily defenseoriented beasts can be very aggressive when hungry or provoked, a fact substantiated by historical accounts of boar hunts. Hunting dogs baying and men on horseback and afoot would give chase, attempting to overtake and kill the quarry. Once cornered, boars

might attempt escape from their harrying adversaries by charging, tusks slashing, through the wall of human, dog, and horse. At times the loss of life was staggering as a powerful animal broke through their ranks. Today, though armed with high-powered weapons, hunters run similar risks when hunting these reluctant adversaries. Pigs will eat whatever they can find. When I was younger, my family raised pigs for food. We fattened them on table scraps, fruit, overripe vegetables from the garden, and grain. They rarely missed an opportunity to supplement their diets by catching and consuming the occasional chicken who entered the pen seeking grain left over from the pigs' dinner. Wild in the woods or tame on the farm, pigs use their noses to < previous page

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Page 198 root the ground looking for edibles. Domestic pigs are occasionally used for work. For example, because of their keen sense of smell, pigs are used to hunt truffles, a mushroom that grows underground. It's common in southern areas of the United States to have a pig or two in the yard to kill snakes. (See Figure 6.9.) Pigs have large canines and well-developed, flat molars. Canine teeth can be used for tearing and shredding, while the molars provide excellent surfaces for grinding. Since animal flesh doesn't require grinding, the latter suggests a surface for handling plant material. Pig dentition, illustrated in Figure 2.9 in chapter 2, indicates a stronger defense- than attack-oriented behavior and a diet where plants form the primary food source with meat an important but limited secondary source. Although primarily long and flat, the slight curve of a pig's mandible maximizes pressure at both the back and front of the jaws. In the front, where incisors, tusklike canines, and bicuspids reside, this pressure provides power for the cutting and tearing of both animal flesh and plant material. In the rear, this pressure provides power for the molars to crush and grind cellulose. This combination indicates primarily defensive, though impressive offensive, behavior necessary for a primarily plant-foraging lifestyle supplemented by hunting and scavenging. A pig's orbits are widely spaced and rotated slightly forward. This position allows limited binocular vision and excellent peripheral vision. Both are necessary for tracking and judging the distance of other animals and objects. This arrangement implies a ground-based

habitat, such as wooded areas, where the field of vision is partially obstructed. In pigs, a flat, narrow cranium, smaller zygomatic arch, and long, narrow jaw indicate crushing and grinding with the back of the jaws to be of greater importance than tearing and cutting with the front of the jaws. This association strongly indicates a diet where plant materials play a greater role than meat. A pig has two toes and narrow hooves, indicating unguligrade locomotion and defense-oriented behavior. (See Figure 4.8 in chapter 4.) The bones in the lower legs are fused, implying a relatively flat habitat where running and walking are the primary modes of locomotion. It also successfully argues, as it does for many large herbivores < previous page

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Figure 6.9. A pig skeleton.. such as horses, cattle, and sheep, for passive defense- rather than attack-oriented behavior. Profile of a Human From arctic to desert extremes, mountaintop to valley, humans walk, run, hunt, work, and play in a wide range of environments. We're at once defensive and aggressive, frail and strong. In prosperous countries, much of the population eats meat as readily as vegetable matter. In poorer countries, meat is a luxury and plants the dietary staple. (See Figure 6.10.) Human teeth are relatively flat, with smaller canines, flat molars, and wide, even incisors. This dental arrangement and shape indicate a behavior pattern where defense supersedes attack. A human's short, flat mandible allows pressure to be maximized at rear and forward portions of the jaws. In the forward area where incisors, canines, and bicuspids reside, this power aids the cutting

and tearing of animal flesh and plant material. Along the sides and rear areas where the well-developed flat molars are, this jaw shape provides the necessary power for crushing and grinding cellulose. This jaw structure, in combination with the teeth, indicates strong defense/offense behavior necessary for a primarily plant-foraging lifestyle supplemented with hunting and scavenging. < previous page

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Figure 6.10. A human skeleton. In human skulls, orbits are rotated to the extreme of facing directly forward, allowing wide-angle binocular vision ahead and to the sides while severely limiting peripheral vision. The resultant wideangle depth perception provides the necessary means for long< previous page

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Page 201 distance tracking of objects and animals. Forward-pointing orbits imply habitats with open fields of vision such as plains, hills, or mountainous areas, and/or partially obstructed fields of vision such as wooded areas and arboreal habitats. The rounded cranium, reduced zygomatic arch, and short jaw of humans indicate that crushing and grinding with the rear portion of the jaws are more important than tearing and cutting with the front of the jaws. (See Figure 3.41 in chapter 3.) This strongly indicates a diet where plants play a greater role in nutrition than meat and primarily passive, defense-oriented behavior over aggressiveoriented behavior. The flat, rough nails of humans, as shown in Figure 4.15 in chapter 4, indicate ground-dwelling or arboreal habitats and a trend toward defense-oriented behavior. Since humans have learned to create ''sharp, retractable claws," this generalization, as is evident through history and current events, tends to fall apart when human behavior is closely scrutinized. The five-toed human foot structure, as with bears, indicates plantigrade locomotion and a ground-based habitat. The fivefingered hand, as shown in Figure 4.10 in chapter 4, strongly indicates a partially arboreal habitat. In humans, bones in the lower front and rear limbs are unfused, indicating that they move freely over uneven terrain. Summary The behavioral inferences presented in this chapter should not be

considered solid empirical data, nor conclusions engraved in stone. Rather, they are intended to illustrate possibilities of behavioral inference through the study of skeletal structure. The reader is encouraged to investigate this subject further through side readings, direct observation of living animals, study of comparative anatomy, and especially, use of the imagination. Life, to a great extent, is unpredictable. No matter how grandiose the conclusion or final the inference, there are exceptions to every rule. < previous page

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Page 202 Chapter 7 Bone-Collecting Basics The collection and study of bones is an important activity for mammalogists and forensic scholars as well as a fascinating and enlightening hobby for laymen. This post-postmortem examination allows researchers to determine an animal's physical attributes, probable environmental lifestyle, species rank, and sometimes the probable cause of death. Besides, bonesespecially skullsmake great conversation pieces. So, other than procuring them from a retail outlet such as Skulls Unlimited International, where can bones be found? Our world is built upon the remains of all the creatures who have ever lived. We find their skeletons fossilized in rock, ground up as sand beneath our feet, and diluted in the air we breathe and the water we drink. More recent casualties lie on or buried just beneath the surface of the ground. Their remains are scattered everywhere: along roads, in fields, and in forests. But just how do you go about collecting them? What precautions should you take? What situations should you avoid? Successful bone collecting takes patience, practice, and an awareness of your surroundings. Although experience is the best teacher, this chapter should help you get started. < previous page

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Page 203 Collection Gear The right equipment will make bone collecting both easier and safer. A usable outfit for this adventure is simple and inexpensive and should consist of the following five items: Brightly colored clothing (hat, shirt, pants, or all three). Gloves, either latex or cloth. Latex gloves offer a sure grip, are nonporous, and are impervious to disease, but they retain body heat and make your hands sweat. The main advantage of cloth over latex is that cloth gloves will not cause hands to sweat and are more comfortable to wear over extended periods. A container for transporting the bones you find. Plastic heavy-duty trash bags are ideal. They are strong, lightweight, and easy to fold up and carry until needed. If you use cloth bags, wash them after each successful excursion. A stick for probing remains. Disinfectant to rinse your hands. A small bottle containing a minimum 10 percent solution of bleach and water will suffice. The Ethics of Bone Collecting Before collecting bones, it is important to understand the role they play in an ecosystem. Collectors should question their motives for gathering bones and consider the long-term effects of their removal. An ecosystem does not waste bones. Rather, they provide food for many creatures. Oils and rancid fats, constantly secreted by bones

during decomposition and weathering, supply food immediately for insects and mammals. Long after the oils have been exhausted, bones continue to furnish a source of calcium and minerals to mammals, such as rodents, who gnaw on them. With their final decomposition, much-needed elements and minerals are returned to the earth. The removal of bones from an ecosystem will deprive some organism, animal or vegetable, of an essential source of food. That leads us to this question: Given their position in the food web, is it ethical to remove bones from their natural setting? If so, under what conditions? Bones are routinely collected for study by colleges, museums, and nature centers. They are scavenged by amateur naturalists and hobbyists for private collections, as well as by artists who use skeletal structures in their work. Nature warehouses are also known to sell items procured from the wild. Do any of these individuals or organi< previous page

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Page 204 zations have valid reasons for the gathering of bones from their natural setting? Institutions, such as nature centers and museums, use bones for study and educational presentations. While these osteology collections are often purchased through biological warehouses, they are still augmented with specimens found in the field. Limiting or eliminating field collection would restrict an important source of specimens. Profit is another motive. A business must sell its products. If these products consist of items found in the wild, such as bones, then a constant source of supply must be established and maintained. Naturalists may find themselves on the horns of a dilemma, as the inclination to collect conflicts with the awareness of bones' role in nature. An artist needs supplies, especially if his or her art involves bones. Art supplies are not cheap, and found materials are the least expensive. It is hard to tell a nine- or ten-year-old, let alone an adult, that he or she cannot keep a found skull. For this person a whole new world has opened up. Many find it difficult to resist the desire to possess, whether for educational, personal, economic, or creative reasons. All collectors must face this issue. This book does not attempt to answer this question or impose ethical constraints. These responsibilities lie with the individual collector. To a greater or lesser degree, ethics

plays a part in any endeavor. While engaged in bone collecting, you are encouraged to trust your own judgment and empathy for nature. How to Find Bones Bones in the wild can usually be spotted by sight if you train yourself to notice unusual shapes and contrasting colors. Once you find a bone, you can launch a search for other skeletal fragments. Color There are no colors quite like those of bones in the wild, so noticing color contrasts between them and their surroundings is the first step to locating skeletal remains. Developing an eye for these contrasts takes practice. At first you will investigate every white object you see. From a distance it is easy to confuse a rock, paper, or piece of whitened wood with a real bone. It is also easy to dismiss slight con< previous page

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Page 205 trasts as not worth examining and thus pass over bones. Don't be discouraged. Practice sharpens and trains the eye at spotting these treasures. Shapes Every bone in a skeleton has a unique shape. When Clearly seen either from a distance or close up, specific bones, such as scapulas and vertebrae, can be quickly recognized by their profiles. Since complete or partial burial by fallen grasses and other vegetation can obscure identifying contours, however, shape recognition is best utilized as an auxiliary to color contrasts in the initial location of bones. Once located through color contrasts, you can recognize skeletal fragments by shape during the close-up work of pattern searches. Search Patterns Two basic search patterns, spiral and a linear zigzag, are used in the hunt for skeletal remains and can be effectively implemented by individuals or groups. Each pattern has a geographic terrain for which its employment is best suited. (See Figure 7.1.) Spiral Pattern When using a spiral search pattern, slowly wind outward from the first bone discovered. If a major portion of a skeleton is subsequently discovered, begin the pattern again, this time using the new find as the center position. This pattern is best suited for use on open land. Depending on the terrain, one of two spiral patterns may be used.

If you find bones on a slope, such as a gully wall or side hill, use an elliptical spiral patterneither oval or teardrop shapedthat opens and widens faster downhill than uphill. On this terrain, bone scattering is primarily a function of gravity, as carcasses have a tendency to roll downhill or be pulled there by scavengers. For bones located in a flat, wide area, such as an open field, use a circular spiral pattern that increases at an even rate in all directions. On this terrain gravity has less effect on skeletal scattering and scavengers are as likely to pull a carcass in one direction as another. Linear Zigzag Pattern With a linear zigzag search pattern, move slowly from side to side while advancing in one direction. Once the likelihood of finding bones < previous page

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Figure 7.1. Three basic search patterns: elliptical spiral, circular spiral, and linear zigzag. The crossed arrows to the right of each image indicate the relative increase and direction of search pattern expansion. by traveling farther in that direction has diminished, return to the starting position. Repeat the process in the opposite direction. This search pattern best suits the banks of watercourses and dry streambeds. Where to Find Bones Bones can be found anywhere, and every place should be investigated. Depending upon your proximity to water, however, some locations may prove more likely prospects than others. Bones are most often found near water sources. Explore along the edges of large bodies of water such as lakes, ponds, and oceans. Investigate dry hummocks in swampy areas and along the banks of streams and rivers. Seasonal sources of water, like dry streams, riverbeds, and arroyos, should also be considered. Bones can also be found away from water. Animals often seek shelter and die in places that are protected and out of the wind. Their bones can be found scattered in areas such as depressions in large open fields or woods, the leeward sides of hills, gullies, and ravines. Locating the bones of small mammals, such as rodents, is difficult. However, if birds of prey inhabit the collecting area, small mammal bones can often be found along cliff bases, under standing dead, trees, and beneath telephone

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Page 207 areas with a clear view when consuming their prey. Bones scattered about the ground may be intact or fragmented, but rarely form complete skeletons. When to Collect Bones Bone collecting can be done at any time of the year, but some seasons are better suited to this than others. The best season to collect skulls and bones is late spring. After the snows have melted, when the previous year's vegetation is still matted down and before new plant growth has started, bones are easier to spot. Their color contrasts strongly with the darker background of dead vegetation in which they lie. At this time bones are often partially or completely uncovered, allowing their shapes to be more pronounced. Summer is a difficult time to find bones because the abundance of standing, color-shaded, fully leafed vegetation tends to obscure bones. Because of the contrast of white bone against rusty leaves and dead grass, fall is also a good bone-collecting season. Because dry, standing vegetation often covers and conceals them, however, bones are more difficult to spot in the fall than in the spring. Wintertime in northern climates is a bad time for bone collecting. Even a slight dusting of snow can obscure skeletal fragments. Bones are hard to spot in a white-on-white world. If you live where there is no snow you may be in luck, however: The fall- or summerlike conditions in these regions offer some hope for visual bone sightings.

Although winter is not the best time to find bones, it is a good time to locate carcasses. Then you can return to the remains in the spring to collect the bones, after nature and time have stripped them of flesh. Searching around such a carcass will often turn up others. During winter everything needs to eat, and carnivores, as well as omnivores, are not apt to pass up an easy meal. Since many animals will be drawn to a carcass, it is not unusual to find the remains of would-be gourmands who were unlucky enough to meet up with larger predators who were staking out the carcass in hopes of finding fresh meat. Final Notes on Collecting The hobby of bone collecting develops a cross-disciplinary understanding of geography, mammalogy, physics, behavioral psychology, and < previous page

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Page 208 ecology. Through such study a person may learn to infer an animal's behavior and general lifestyle and in this way develop tools for understanding nature and its complexity. The hints supplied in this chapter should make the search for bones easier. Hunting of any sort always presents dangers to the hunter, however, and the following sections discuss some of the hazards inherent in bone collecting. Safety Precautions Hazards to health and safety are inherent in any expedition. Since knowledge often alleviates fear, collectors will find it important to develop an awareness of the hazards peculiar to bone collecting. The risks of many of the perils discussed in this chapter are low and all can be diminished, if not eliminated, with proper attention to detail. When in pursuit of bones, safety should be the primary concern. Many dangers can befall unwary and unprepared collectors. Including the standard hazards associated with hiking and climbing, the most likely dangers arise from fellow humans, wild animals, and the weather. Roadside Safety Many animals are killed along our nation's major transportation routes. If you insist on examining roadkill, don't be stupid. At all times wear bright clothing, be alert to the sounds of any motorized vehicle, and keep a close watch up and down the road or train tracks. These precautions will only mitigate the danger. When crouched

down looking at a dead animal lying in or along the side of the road or train tracks, a person is difficult to see. Even if you're wearing bright clothing, a driver may not become aware of your presence until it's too late. The only sure way to not be hit is to stay out of and away from roads. Remember, cars and trains are heavy machines that build up momentum as they move. Often traveling in excess of fifty miles per hour, they take a while to stop when brakes are applied. An automobile may take twenty feet or more to come to a complete stop. Since trains are heavier than cars, a suddenly braking train may slide hundreds of feet along a track before coming to a halt. A screech of rubber on asphalt, or steel on steel, and either you're safe or you're roadkill. Because of the danger presented by motorized vehicles of any kind, leave the remains of road-killed animals alone. < previous page

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Page 209 Hunting Season Searching for bones in the outdoors can be dangerous during hunting season and the best advice is to stay out of the woods and fields at this time. Although many hunters are safe and conscientious, some are not. Unsafe hunters have been known to make "sound shots"firing a gun in the general vicinity of a sound without actually seeing the targetor fire in rapid succession at an animal without taking sharp aim. Both "hunting techniques" are reckless and dangerous. Although good hunting practices and techniques mitigate these dangers, even they produce an inevitable stray bullet. Wild Animals It is easy to become so engrossed in a search that you are unaware of events going on around you. With the increasing encroachment of humans into the habitat and territories of wild animals, it is not unlikely that a backyard or backcountry bone collector may find himself face to face with a bear or mountain lion. Usually this isn't a problem, since most animals tend to shy away from humans. This response shouldn't be counted on, however. When faced with such a predicament the better part of valor is recommended. Retreat, but don't act like prey. If additional information is desired, most nature centers provide cautionary brochures on actions a person should take when confronted by aggressive wild animals. Weather Conditions

Humans often consider themselves superior and invulnerable to natural events. Any number of outdoor casualties can attest that nature is indifferent to our arrogance. Since many hiking and outdoor books detail effective cautionary tactics, I will just say that on any excursion into the out of doors, be prepared. Each season and geographic region has both predictable and unpredictable weather patterns. Carry gear sufficient for expected as well as inclement weather. But most of all, know your limits. Many people overestimate their physical capabilities and underestimate the forces of nature. Health Hazards It should go without saying that you should not collect fresh remains. It takes a while for nature to scour bones clean of flesh and disease. < previous page

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Page 210 The larger the animal, the longer it takes. Depending on the age of the bones and whether the climate is humid or arid, you may be exposed to several types of viral or bacterial contamination. Therefore, wait until nature has removed the bulk of, if not all, flesh and sinew from the bones, then collect and clean them. The Dangers of Decomposition Once dead, all organisms decompose, with muscle and other soft tissues decaying faster than bone. The speed at which this process occurs is directly related to the amount of moisture in the air and on the ground surface. The presence of moisture speeds up decomposition. Humidity keeps flesh somewhat moist, providing an ideal environment for the organisms that cause tissues to break down and rot. An arid climate like a desert inhibits decay but does not stop it. The bacteria that promote decay, and other organisms, such as flesh-eating insects, are still active. Decomposition does not happen overnight. Sometimes it takes several years for a carcass to skeletonize. Even after the flesh is removed from the outside of bones, marrow is still sealed inside. A soft fatty connective tissue, marrow usually takes a long time to empty from the hollow center and spongelike areas of a bone. In my backyard, I have ten-year-old elk bones still full of marrow. (See Figure 7.2.) Exposure to rotting flesh presents immediate hazards to health and well-being. Although these risks drop in direct proportion to a bone's cleanliness, they never go away completely. Three major infections may be caused by handling decaying remains without

proper precautions: blood poisoning, botulism, and tetanus. Blood Poisoning Also called septicemia, blood poisoning is an infection caused by the invasion of the bloodstream by virulent bacteria. Once introduced through an open wound, such as a cut or deep scratch on your hand, the infection spreads, swelling tissues and sending painful livid red streaks across afflicted body parts. Of the three risks mentioned here, this is the greatest. Botulism Also called acute food poisoning, botulism is caused by botulin, a toxin secreted by the spore-forming bacterium Clostridium botulinum. Botu< previous page

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Figure 7.2 A split section of femur. Fats and marrow fill the center hollow and the spongelike material at the bone ends. The enlarged cutout section on the right illustrates the porous nature of this material. < previous page

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Page 212 lin is transmitted through contact with the mucous membranes found in your nose or mouth. You don't have to eat rotten flesh to be affected. All you need to do is pick up a bone that still has some flesh clinging to it or rancid oils oozing from it and, with the hand that touched the rotten flesh, inadvertently wipe your nose or mouth. Tetanus An acute infectious disease, tetanus is caused by a toxin produced by the bacillus Clostridium tetani. The toxin, often introduced through an open wound, causes rapid spasms and prolonged contraction of voluntary muscles. An early symptom of tetanus is characterized by the spasming of the jaw muscles that eventually results in the inability to open the jaw. It is for this reason that advanced tetanus is also referred to as lockjaw. Contagious Diseases Death is not always the result of old age or accident. Animals, both domestic and wild, die from disease or fall prey to accidents due to debilitation caused by a disease. Regardless of how an animal dies, a pathogen can cling to decaying flesh, bones, or hair. The fresher the carcass, the greater the danger of contamination to a collector. Four of the most common diseases are discussed here: distemper, rabies, bubonic plague, and anthrax. Distemper and Rabies Distemper is a highly contagious virus whose infection is marked by fever and respiratory and nervous symptoms. Rabies is an acute viral disease of the nervous system of warm-blooded animals. These

are two of the most prominent diseases among animals. Both can make an animal disoriented, causing it to wander into areas outside its normal territory. If it wanders onto a road, it may be struck and killed by a passing motor vehicle. These diseases can be contracted or carried through the handling of carcasses. Although rabies is infectious to humans, distemper is not. Pet lovers beware, beware, because humans can act as carriers for these diseases and infect pets and livestock. Bubonic Plague Also called the Black Death, this plague decimated Europe in the fourteenth century, killing approximately one quarter of its human popu< previous page

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Page 213 lation. The disease, caused by the bacterium Pasteurella pestis, is transmitted through the bites of fleas that live on warm-blooded mammals. In the Middle Ages it was a large rat population that hosted the fleas. Today the disease is still transmitted primarily through large populations of rodents such as squirrels and prairie dogs, but any mammal can be a carrier of plague-infested fleas. Although fleas require a live host to survive and do not live long after a host is dead, do not take the chance of contracting this disease by handling fresh carcasses. Anthrax Although controlled, anthrax occasionally flares up in domestic livestock and wild animals. It is an infectious disease of warmblooded animals caused by the spore-forming bacterium Bacillus anthracis. It can be transmitted to humans through the handling of infected products such as hair. Precautions You Can Take There are a number of simple precautions you can take to guard your health and safety. First, wear brightly colored clothes. The best color is fluorescent orange, also called hunter's orange. This color stands out well against most backgrounds, reflects light, is attention getting, and makes the wearer easy to see. Next, wear cloth or latex gloves when handling skeletal remains to protect your hands against possible contamination. Latex gloves have the advantage of being nonporous and, as long as they remain undamaged, impervious to disease.

Clean all clothing after each successful collecting excursion. Soak all articles, including gloves, in a bleach-water solution, then wash them in warm soapy water. After handling remains, avoid touching your eyes; body orifices, such as mouth and nose; and any cuts and abrasions. Prevent contagion by washing your hands with a 10 percent solution of bleach* and water. Disinfect collected bones by soaking them overnight in a solution of nine parts water to one part bleach. When soaking time is up, *The best bleach to use is Clorox. Other bleaches often contain a high percentage of lye. < previous page

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Page 214 remove and, using a scouring pad or old toothbrush, wash them in warm soapy water, then let them air dry. If you can, dry them in the sun, as ultraviolet radiation kills bacteria. If desired, use some form of lacquer, clear spray paint, or floral plastic spray to seal the bones. This will prevent possible infection from future handling. Chapter 8 provides details on bone disinfection, preparation, and preservation techniques. Conclusion Collecting bones can be fun, but you must be aware of the risks to yourself and others. Play it safe and stay off roads and train tracks. When hunting season comes around, do not go into the woods and fields. When collecting skulls and other bones, take the precautions of wearing gloves and bright clothes. Remember to keep your own life and bones intact. < previous page

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Page 215 Chapter 8 Bone Preparation and Cleaning Because of the health risks associated with bones found in the wild, specimens should always be sanitized. In fact, bone cleaning should be considered one of the single most significant tasks undertaken by collectors. Many bones, even those weathered for several years, may still have remnants of flesh and tendons attached to them. Collectors should remove these tissues to eliminate both possible disease sources and offensive odors. Depending on your intended use, one of two types of cleaning may be undertaken: home quality and museum quality. Home-Quality Specimens Most people do not gather bones for scientific purposes but rather for display in homes or private rooms. These collections often consist of loose bones that may be strung together and mounted but more often remain spread out along shelves or stashed in boxes. The primary concerns for cleaning home-quality specimens are hygiene and aesthetics. Home-quality cleaning requires that the following four conditions be met. < previous page

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Page 216 All muscle and ligament tissue must be removed from the bones. Bones should be sterilized both inside and out. All surface oils must be removed, leaving bones dry, not greasy, to the touch. Bones should be white, off-white, or slightly yellow in color. The Cleaning Kit The basic components of a home cleaning kit are readily available within most homes, supermarkets, and hardware stores. Depending on the specimens' conditionflesh-free or with flesh still attachedall or some of the following items may be used. Safety goggles, to protect your eyes from splattering hot water, caustic chemicals, and chemical solutions. Disposable latex gloves, to protect your hands from hot materials and caustic cleaners. Old clothes that cover your arms to the wrists and your legs to the ankles. A drop cloth or newspapers, used for drying specimens. A large pot or five-gallon metal can used exclusively for boiling bones. Preferably two, but at least one, three- to five-gallon plastic pails used strictly for soaking and scrubbing bones. Several cutting and scraping utensils such as scalpels, paring knives, old steak knives, toothpicks, or thin, flat, narrow-tipped pieces of

wood. Several soft, abrasive scraping utensils such as a plastic dishwashing pad, plastic vegetable scrubber, or a toothbrush. A kitchen stove, a camping stove, or an open fire with a grate, for ''cooking" bones. Be aware that boiling bones, especially old ones, can produce noxious, foul-smelling fumes. When cleaning is performed in the house, use of a range hood or exhaust fan is recommended. One or all of the following basic household cleaning chemicals: ammonia, Clorox bleach, or a degreaser. During the bone-cleaning process these chemicals must be used outdoors or in well-ventilated areas. Once this kit has been assembled the cleaning process can begin. Use only those items necessary for the job at hand. Once kit items are used for bone cleaning, they should never be used for any other purpose. < previous page

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Page 217 Initial Preparation No matter how spotless bones may appear when found, they should always be considered possible sources of infection. Therefore, all specimens should be cleaned and disinfected before being brought into your home for display. Although this will not eliminate all infectious agents, it will greatly reduce risks of contagion. The preparation process discussed in this section assumes relatively flesh-free specimens. If you have fleshed specimens, use a knife or your gloved hands to remove as much muscle and ligament material from the bones as possible, being careful not to cut or scratch them. Next, cover the ground or floor with the drop cloth or newspapers. Then mix a 10 percent disinfectant solution of approximately 1.6 cups bleach or ammonia to 1 gallon of water. Soak the specimens overnight. Wearing gloves and goggles, remove the bones one at a time and gently scrape away as much softened flesh and ligament material as possible. If the bones are already free of ligament and muscle tissue, simply scrub them with a brush. When finished, lay the specimens on the drop cloth to dry. If you're working with small bones, the above procedure should adequately clear them of fat and grease. If the bones are large, however, the cleaning process will require another step. Once the scrubbed and disinfected bones have dried, the larger leg and hip bones should be drilled at certain positions along their sides and ends. This technique, illustrated in Figures 8.1 and 8.2, will help to clear marrow and other fatty substances from the bones.

Skulls require more preparation than other skeletal structures. In addition to the general preparation detailed above, assuring the removal or absence of brain tissues from the skull is very important. If brains are not removed prior to prolonged soaking or cooking, they may expand and force the brain case apart. If brains are still in the skull, first soak the skull in warm water and then remove the brains with a bent wire or soft-ended implement. Do this gently, as the divisional plate of bone inside the brain case is fragile. Once the major portion of brain material has been removed, rinse the brain case with warm water to remove any remaining tissue. Cleaning Methods Cleaning bones is a relatively simple process. Two basic methods are discussed here: maceration and boiling. Choose whichever method < previous page

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Figure 8.1. Illustrations of bone-drilling techniques used to evacuate marrow and other fatty substances from large leg bones during the cleaning process. < previous page

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Figure 8.2. Illustrations of bone-drilling techniques used to evacuate marrow and other fatty substances from large hip bones during the cleaning process. you prefer, depending on available time and materials, as well as your level of patience. You should also consider the sensibilities of your neighbors, parents, or spouse, as bone cleaning can be an odoriferous process. Maceration Maceration involves submerging bones in a covered bucket of 1.5 percent ammonia waterin the proportion of two quarts water to one ounce ammonia. Clorox bleach may be substituted for ammonia.* Leave bones in the solution a few weeks or months until all tissue decays. Then remove the bones from the solution, scrub them gently, rinse with warm water, and allow to dry thoroughly. The soaking

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Page 220 process can take weeks or months and generates offensive odors, so it's best done only in rural areas with distant neighbors. Maceration is certainly not the quickest method of cleaning bones, but it is perhaps the best home method for preserving delicate structures in both large and small animals. For example, the most difficult bones to clean and preserve are those in a skull that support the sinus membranes. These waffled, honeycomblike structures are very delicate. In fact, many people, even museum personnel, simply remove these structures to facilitate cleaning. By using maceration, however, they can be nicely preserved. Boiling An alternative to maceration is boiling, simply cooking bones in water or a weak bleach or ammonia solution. Because bones often smell bad when boiling, it is best to do this outside on a camp stove. You could try it on your kitchen stove, but even if you use an exhaust fan you're likely to drive everyone out of the house. To prepare bones for boiling, soak them overnight in a 1.5 percent ammonia solution (two quarts water to one ounce ammonia). This solution may be used for cooking the bones the next day. Tie a long string to each specimen before immersing it so that it can be lifted and examined from time to time during cooking. When you're ready to cook, add more liquid (water or solution) to the pot if necessary so that the specimens are covered.* Bring the liquid to a rolling boil, then reduce to a gentle boil by lowering the heat. Stirring occasionally, cook the specimens until flesh and ligaments separate easily from the bone. Allow larger bones to cook

longer, particularly those that have been drilled. The basic problem with this cleaning method is that boiling can loosen bone joints, especially those in the skull. Be very careful when boiling skulls, especially those of juveniles and smaller mammals. If the skull does fall apart, you can reconstruct it by using epoxy glue, superglue, or even liquid solder in a tube. Be careful to position the joints exactly, because once the glue or solder has set you won't get another chance. Do this outdoors or in a well-ventilated area, and wear gloves. * Note: To avoid adverse chemical reactions, do not add bleach solution to ammonia solution when soaking or cooking bones. < previous page

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Page 221 Prolonged cooking of skulls often results in the softening and eventual disintegration of the cartilagelike material that holds teeth in their sockets. Should this occur, carefully gather the teeth and later reset them in their proper position using rubber cement, superglue, or epoxy glue. Boiling can also crack teeth, especially those of larger mammals. This happens because sudden changes in temperature cause tooth enamel to shrink at a different rate than the tooth's bony center. To minimize tooth-cracking, limit sudden hot-to-cold temperature changes by immersing skulls in a bucket of hot water as soon as you remove them from the pot. If gentle scrubbing is required, do this while the skull is still submerged. When the liquid has cooled, remove the skull and allow it to dry. To further prevent teeth from cracking, coat them with polyurethane, clear fingernail polish, or paraffin wax during the final cleaning, as discussed below. Final Cleaning The final scraping and probing can be the most tedious part of the bone-cleaning process, but is essential to ensure that all tissue has been removed. With gloved hands, remove specimens from the maceration bucket or use the strings to lift bones one at a time from the boiling pot. Immediately upon removal, use a small, hard instrument to pick or scrape off all extraneous material from each specimen, occasionally rinsing the bones in a bucket of hot water. When you have removed as much material as possible with the hard scraper, switch to soft scrubbing pads. Immerse the specimen in a bucket of hot water and gently but thoroughly scrub as much of its

surface area as you can reach. Then set the specimen aside on the paper or drop cloth and move on to the next. When you have cleaned all of the bones, you need to degrease them with a final rinse, since you pulled them through a thin layer of oil when removing them from the maceration bucket or boiling pot. To do this, fill the bucket with a 10 percent solution of hot water and ammonia or bleach (two quarts water to 6.4 ounces ammonia). Immerse the bones in this solution and let stand for one hour, or until the liquid has cooled. Fill another bucket or pot with a 10 percent solution of ammonia or bleach and immerse the bones one at a time. This time scrub them gently but thoroughly with a soft pad or toothbrush. When finished, place the specimens on the paper or cloth and let dry < previous page

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Page 222 in a well-ventilated area, preferably outside in the sun, for two weeks longer. If you wish, bones can be whitened by simmering them approximately six hours in a 10 percent solution of water and hydrogen peroxide or bleach. Check the bones frequently, as prolonged submersion can make the bones chalky and cause them to crumble. Also, be careful not to make the solution too strong, as strong solutions can cause severe and rapid bone deterioration. Sealing Bones Once cleaned and dried, specimens should be sealed for longer preservation. Sealing home-quality specimens is important because most, if not all, of the bone's natural grease sealant has been removed during the cleaning process, thus leaving bones very porous and subject to crumbling and splitting. Most hardware stores and home hobby centers carry several commercial sealing products. Use these materials in open, wellventilated areas. The following five products are easily obtainable and relatively simple to apply. Bones can be sealed with a later of clear wax such as paraffin. A wax coating can be polished, but once it is rubbed in it attracts dust, is difficult to clean, and, like furniture, requires occasional upkeep. Researchers find this sealant a plus because it can be removed, allowing close study of the bone. Available in most hardware and woodworking stores, the active lifespan of varnish is shorter than other lacquer-type sealants and it

can be difficult to apply an even coating to specimens. Varnish also tends to crack and yellow with age, but for the short term it provides easy upkeep. Polyurethane, a permanent sealant, is available in hardware and woodworking stores. With a long active lifespan, it is easy to maintain and has a clear, durable finish that resists cracking with age. If kept in constant sunlight, however, it may yellow. Available in home hobby centers, hardware stores, and even in large supermarkets, clear enamel spray paint combines easy administration and upkeep with long life. The application of a minimum of three coats is recommended on specimens to ensure total coverage. Clear plastic floral spray is available in home hobby centers and < previous page

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Page 223 offers the advantages of easy upkeep and simple application with long life. A minimum of three coats should be applied. Museum-Quality Specimens Museum-quality specimens differ from home-quality specimens in aesthetic appeal. Whereas home specimens are used for public handson display and require extensive hygiene considerations, museum osteology specimens are used for research and require the use of long-term preservation techniques. Therefore, museum specimen preparation and cleaning is less stringent concerning hygiene, since lubricating oils and grease and connecting ligaments are often left intact. This cleansing level requires that the following two conditions be met: All residual flesh should be removed but connecting cartilage and ligaments should be left intact. Internal fat sources, such as marrow in large bones, should be removed, but bones can retain a certain amount of grease. Oil retention maintains bone flexibility, keeping them from cracking, though leaving them greasy and potentially odoriferous with time. A researcher's comprehension of skeletal structure and species identification requires the presence of all major connective ligaments and structures. From this, the science of osteology, the study of bones, recognizes specimen skeletons as ligamentary or disarticulated. Small mammals up to the size of a fox are generally treated as ligamentary skeletons. Their bones, too small and delicate for

mounting, are cleaned with their connecting ligaments attached. The bones of mammals larger than foxes are separated and referred to as disarticulated skeletons. The bones may then be drilled, wired, and bolted together for mounting. Cleaning Methods The cleaning and preparation of museum-quality specimens is similar to that of home-quality specimens but with less stringent hygiene requirements. As mentioned above, for research purposes ligaments are preferred intact and, when possible, still connected on museum specimens. Even when large bones are drilled to help relieve marrow, all of the grease and oils are not removed from the bone. Rather, a substantial portion is left to prevent bones from cracking and splitting < previous page

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Page 224 when drying. Although these specimens may be cleaned through boiling or maceration, many museums prefer to use dermestid beetle larvae for cleaning almost all specimen bones. The various species of the genus Dermestes, known by several names including bacon beetle and buffalo bug, have historically been rated as destructive pests that consume hides, pelts, dried meats, and other animal products. (See Figure 8.3.) Since it's the growing larvae that consume the greatest amount of food and are most useful as bone cleaners, a working colony requires a fair number of adult beetles for reproductive purposes. A sufficient number to start a colony can be found in decaying carcasses, especially where the meat has dried up. In-house colonies are placed in a sealed bugproof box to prevent their escape and spread into areas where they can wreak havoc among stored animal products. Low temperatures make beetles and larvae inactive, and vibrations disturb them, so it is best to keep them

Figure 8.3. Three examples of dermestid beetles. < previous page

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Page 225 in a warm, quiet place. A constant temperature of 80 degrees Fahrenheit is best. When a large number of larvae are concentrated in a small space, such as the bugproof box, a diminishing food supply forces them to eat any new material that is introduced. Single layers of hard, dried flesh-coated bones are sandwiched between two layers of cotton in shallow cardboard boxes. These boxes are then placed in the box containing the bugs. Depending on the amount of flesh remaining on a carcass, an active dermestid colony will usually clean small skulls in twenty-four to forty-eight hours. Keeping a colony alive requires food in the form of dried meat to be furnished when unclean skulls or skeletons are not on hand. Final Cleaning Specimens "cleaned" by a colony of dermestid beetles undergo two additional cleansing steps. Once specimens have been removed, they are allowed to soak for twelve hours in a 10 percent ammonia solution (two quarts water to 6.4 ounces ammonia). The ammonia loosens any pieces of meat or cartilage missed by the beetles and removes excess grease from the bone. Depending on size, specimens are then soaked in water for twenty-four hours or longer. After the water has been poured off, specimens are rinsed in fresh water and then set aside to dry. Once dry, museum specimens, unlike those destined for home display, are not sealed. Coverings of any kind limit a researcher's access to the actual bone material.

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Page 227 Glossary of Terms A AcetabulumThe cup-shaped socket joint of the hip that accepts the ball-like structure of the femur, or thighbone. AnimaliaThe kingdom that includes all animal organisms. AnthraxAn infectious disease of warm-blooded animals caused by the spore-forming bacterium Bacillus anthracis. This disease can be transmitted to humans through the handling of infected products such as hair. It is characterized by external ulcerating nodules or by lesions in the lungs. Articular processesThe two structures located at opposite ends of a vertebra. The inferior articular process, facing up on one end, and the superior articular process, facing down on the other, overlap with their opposite counterparts, up to down and down to up, on following and preceding vertebrae. (See Figures 5.2 and 5.3.) B Bacillus anthracisThe spore-forming bacterium that causes anthrax. BacteriaAny of a class of microscopic plants, Schizomycetes, having round, rodlike, spiral, or filamentous single-celled or noncellular bodies. Present in soil, water, organic matter, and the bodies of plants and animals, these organisms are essential to decay. While they can be beneficial in nutrition and digestion, they can also be pathogens causing sickness and disease.

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Page 228 BicuspidsAlso called the first premolars, the two teeth positioned just after the canines and just before the molars in the upper and lower jaws. Bicuspid refers to the shape of their tips, which end in two conical points, or cusps. Binocular visionThe type of vision in which both eyes focus on a single object at the same time, forming one three-dimensional image. Bipeds The term used to describe animals that walk upright on their two hind feet. Blood poisoningAlso called septicemia, an infection caused by the invasion of the bloodstream by virulent bacteria. BotulinA toxin secreted by the spore-forming bacterium Clostridium botulinum. Botulin is transmitted through the mucous membranes found in the nose, mouth, and eyes. BotulismThe medical name for acute food poisoning caused by the toxin botulin. BreastboneSee sternum. Bubonic plagueThe disease caused by the bacterium Pasteurella pestis and transmitted to mammals through the bites of infected fleas. This disease is also called the Black Death or simply the plague. C CanineOf or relating to dogs or the dog family.

Canine teethTeeth that are pointed and conical in shape and positioned between the incisors and bicuspids. CarcassThe body of a dead animal. CarnassialRelated to or being the teeth of a carnivore specialized for cutting. The carnassial teeth include the bicuspids and the molars. CarnivoreAn animal whose primary source of food is animal flesh. Carpal bonesThe bones that make up the wrists of an animal's front legs. CartilageA translucent, flexible, elastic tissue that composes most of the skeleton of embryos and young vertebrates. During growth and development the majority of this tissue is converted into bone in larger vertebrates. Caudal vertebraeThe final vertebrae in the spine, these structures extend from the sacral vertebrae, forming the tail of a mammal. Cervical vertebraeThe vertebrae that extend from the base of the skull to the first rib. CheekboneThat portion of the zygomatic arch, also called the jugal < previous page

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Page 229 bone, that forms the lower portion of the orbit and extends back along the side of the cranium, where it connects with the squamosal bone. ChordataThe phylum that includes animals with spinal cords. ClassThe rank-category below phylum and above order in the Linnaean classification system. ClavicleAlso called the collarbone, this bone links the scapula to the sternum. Clostridium botulinumThe spore-forming bacterium that secretes botulin, the toxin that causes botulism. CoccyxThe tailbone of a human. CollarboneSee clavicle. Costa cartilageThe cartilage that connects the shaft of a rib to the sternum. CraniologyThe study of skulls, particularly human skulls. CraniumThe part of the skull that encloses the brain. D DecompositionThe process of breaking down organic material into smaller and simpler compounds. DentitionThe number, kind, and arrangement of teeth in upper and lower jaws. Depth perceptionAssociated with binocular vision, the ability to

perceive relative locations of objects within one's range of vision. Dermestid beetleA type of beetle used by many museums for cleaning flesh from bones. DigitigradeWalking on the digits, or toes, with the wrist and/or heel bones held off the groundthe common mode of walking among most four-footed carnivores, omnivores, and small herbivores. DigitsThe scientific term for toes and fingers. Distal phalanxThe last, or end, bone of the phalanges, or toes. DistemperA highly contagious viral disease characterized by fever and respiratory and nervous symptoms. Double-curved spineThe name applied to spinal columns whose thoracic region bows out while the lumbar region bows inward. This spine shape is associated with humans. E EntomologyThe study of insects. Eye socketThe bony cavity that holds the eyeball, also called the orbit. EyeteethSee canine teeth. < previous page

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Page 230 F False pelvisAlso called the greater pelvis, this term refers to the broad, flangelike structures of the hip located just above, or before, the true pelvis. False ribsThese ribs collectively embrace the vertebrochondral ribs and the vertebral, or floating, ribs. FamilyThe rank-category below order and above genus in the Linnaean classification system. FelineOf or relating to cats or the cat family. Felis catusThe scientific name for the domestic cat. FemurAlso called the thighbone, the single large bone that forms the upper portion of the back leg. FibulaThe smaller of the two bones that form the lower portion of the back leg. Floating ribsSee vertebral ribs. Food poisoningThe common name for botulism. Foramen magnumThe opening at the rear or base of a skull through which the spinal cord passes to become the medulla oblongata. Functional morphologyThe field of science that studies and interprets the functional aspects of anatomy, physiology, and osteology. G

GenusThe rank-category below family and above species in the Linnaean classification system. H Head of the ribThe lower portion at the spinal end of a rib that attaches between two vertebrae. This structure forms the primary attachment point of a rib to the spinal column. HerbivoreAn animal whose primary source of food is plant material. HierarchyA graded or ranked series of objects or classification groups. Home-quality specimensSpecimens intended for home display that are cleaned with strict regard to health and hygiene considerations. HumerusThe single large bone that forms the upper portion of the front leg. I IchthyologyThe study of fish. IliaThe broad flangelike structures that constitute the false pelvis. IncisorsThe front cutting teeth, located forward of the canine teeth in the upper and lower jaws. Inferior articular processThe articular process that faces up on one end of a vertebra and overlaps with its counterpart, the superior articular process, on preceding vertebrae. (See Figures 5.2 and 5.3.) < previous page

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Page 231 Intercostal spaceThe space between ribs in the rib cage. Intervertebral diskThe relatively thick cartilaginous disks that function as padding and shock absorbers between two vertebrae. IschiaThe opposing eye-holed structures that constitute the true pelvis. J Jugal boneSee cheekbone. K KingdomThe primary rank-category in the Linnaean classification system from which all other classification groups are subdivided. L LeewardFacing into the wind or the side opposite the direction of the wind. Linnaean classification systemThe binomial classification system developed by Carolus Linnaeus, which classifies animals according to their structural similarity. Lumbar vertebraeThe vertebrae immediately following the thoracic vertebrae and just prior to the sacral vertebrae in the spine. These vertebrae are associated with the lower back. M MacerationA method of cleaning bones in which specimens are immersed in a weak ammonia solution until all flesh has decayed

from the bone. MammaliaThe class that includes warm-blooded animals who have hair on their skin and nourish their young with milk secreted by mammary glands. MammalogyThe study of mammals. MandibleThe lower jaw. MasseterThe muscle group that connects the back of the lower jaw and the zygomatic arch. This muscle, along with the temporalis, raises the lower jaw. MaxillaThe upper jaw. MetacarpalsThe bones of the front foot that extend from the phalanges back to the carpals. MetatarsalsThe bones of the back foot that extend from the phalanges back to the tarsals. MolarsThe rear grinding teeth located behind the bicuspids in the upper and lower jaws. Monocular visionThe type of vision in which each eye focuses on a separate object, providing two individual two-dimensional images. Museum-quality specimensSpecimens intended for professional research and cleaned with strict regard to long-term preservation. Ligaments are purposely left intact. < previous page

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Page 232 N Neck of the ribThe portion of a rib that curves away from the head and tubercle to form the major structural body of a rib. The end of this structure, opposite the head and tubercle, attaches via costa cartilage to the sternum. O OlfactoryOf, related to, or connected with the sense of smell. OmnivoreAn animal that eats both plants and animals and can use either of these as primary food sources. OrbitAlso called the eye socket, the bony socket that holds the eyeball. OrderThe rank-category below class and above family in the Linnaean classification system. OsteologyThe scientific field that studies and classifies bones. P Parietal bonesThe two bony plates that fuse together to form the rear portion of the cranium. Pasteurella pestisThe scientific name for the organism that causes bubonic plague. Pectoral girdleThe structure composed of the scapula and clavicle that provides the power and foundation for the articulation, or movement, of the front limbs.

Pelvic girdleAlso called the hipbone, this large structure anchors to the base portion of the spine, called the sacrum, and forms the foundation for the skeleton. PerissodactylsNonruminant hoofed mammals that usually have an odd number of toes. PhalangesThe bones that form the digits of the front and back feet. PhylumThe rank-category below kingdom and above class in the Linnaean classification system. PlantigradeWalking with the entire foot (the digits, wrist, and heel bone) held on the ground. The common method of walking among humans and bears. PremolarsSee bicuspids. R RabiesAn acute viral disease of the nervous system of warmblooded animals. RadiusThe largest of the two bones that form the lower portion of the front leg. Rib cageThe cagelike structure formed by the attachment of the ribs to the sternum and thoracic vertebrae. This construction is sometimes referred to as the thorax. < previous page

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Page 233 RoadkillThe name given to animals killed on roads by motorized vehicles. RodentAny member of the order Rodentia. These gnawing mammals have single pairs of incisors in their upper and lower jaws. RostrumThe portion of the skull forward of the orbitals formed by the nasal structure and maxilla. RuminantsEven-toed hoofed, or ungulate, mammals that chew their cud (regurgitated grass) and have complex, three- or fourchambered stomachs. S Sacral vertebraeThe vertebrae immediately following the lumbar vertebrae and just prior to the caudal vertebrae. These structures fuse together to form the sacrum. SacrumThe structure created by the fusion of the sacral vertebra and that anchors to the hip or pelvic girdle. Sagittal crestThe raised suture formed by the fusion of the parietal bones of a skull. ScapulaAn often triangular-shaped bone attached to the rib cage via muscles and the sternum via the clavicle, this bone forms the major portion of the pectoral girdle and joins with the humerus. SepticemiaThe medical name for blood poisoning. Shoulder bladeSee scapula.

SinusThe cavity formed by the bone of a skull that, in conjunction with the nostrils, forms the passage and filtration system for air. It is associated with the mechanism for the sense of smell. SpeciesThe last rank-category in the Linnaean Classification System. Spinal cordThe primary nerve conduit that runs through the vertebral column to the brain. SpineSee vertebral column. Spinous processThe structure that projects vertically from a vertebra. SquamosalThe last bone of the zygomatic arch positioned after the jugal bone and that connects to the cranium. SternumAlso called the breastbone, this compound bone connects ribs and/or shoulder girdle. Superior articular processThe articular process that faces down on one end of a vertebra and overlaps with its counterpart, the inferior articular process, on following vertebrae. (See Figures 5.2 and 5.3.) SuturesThe jagged or scribbled joint produced when two bones fuse together. < previous page

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Page 234 SystematicsThe science of taxonomic classification. T Tarsal bonesThe bones that make up the ankle of the rear legs. TaxonThe term applied to a single classification group, such as order or genus, within a classification system. TaxonomyThe orderly classification of plants and animals according to their presumed natural relationships. TemporalisThe muscle positioned along the side of the skull that runs between the zygomatic arch and the skull. This muscle connects the rear portion of the lower jaw to the skull and, along with the masseter, raises the lower jaw. TerrestrialOf or related to the earth or its inhabitants. TetrapodsThe term used to describe animals that move about on all four of their feet. Thoracic vertebraeThe structures of the vertebral column along which the ribs attach. These vertebrae follow the cervical vertebrae and are just prior to the sacral vertebrae. ThoraxSee rib cage. Transverse processesThe structures that project laterally from either side of a vertebra. True pelvisAlso called the lesser pelvis, this term refers to the cupped, eye-holed structure of the hip located just below, or behind, the false pelvis.

True ribsAlso called the vertebrosternal ribs, true ribs extend along the thoracic region of the spine, attaching along and ending at the base of the sternum. TubercleThe portion of a rib above the rib head that attaches to a vertebra. This structure forms the secondary attachment point of a rib to the spinal column. U UlnaThe smaller of the two bones that form the lower portion of the front leg. UngulatesHoofed mammals. UnguligradeWalking on the distal phalanx bones, or ends of the toes, with all other bones of the foot held off the groundthe common method of walking among most large four-footed herbivores. V VertebraeThe skeletal structures that when connected or stacked together form the vertebral column. Vertebral bodyThe primary mass of bone often located below the vertebral foramen. < previous page

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Page 235 Vertebral capsThe caps that affix to ends of vertebrae in live animals, providing a smooth surface covering between the vertebrae and intervertebral disks. Vertebral columnThe structure, composed of vertebrae, that shields the spinal cord and forms the primary connecting structure of a skeletal system. Vertebral foramenThe central opening in a vertebra through which the spinal cord passes. Vertebral ribsThe ribs that attach only to the thoracic vertebrae and follow the vertebrochondral ribs. Vertebrochondral ribsStarting from a spot parallel to the bottom of the sternum, vertebrochondral ribs extend along the thoracic region immediately following, and look remarkably like the true ribs. Vertebrosternal ribsAlso called the false ribs, these ribs extend along the thoracic region of the spine, attaching along and ending at the base of the sternum. VirulentExtremely poisonous and fast-acting. VirusAny of a large group of submicroscopic infective agents that are regarded as either the simplest microorganisms or extremely complex molecules. Z Zygomatic archThe bony arch, formed by the jugal and squamosal bones, that extends back from the cheekbone along the cranium and usually anchors just forward and above the ear on the cranium.

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Page 237 Appendix A Things to Do This appendix provides several classification and hands-on exercises designed to illustrate and instruct in the application of material presented in this book. Skull Classification Figures A.1A.3 show two views of three skulls. Using the information provided in chapters 2 through 5, classify each skull according to its probable environmental lifestyle: carnivore, herbivore, or omnivore. Skull Structure Identification Using the red fox skull illustrated in Figure A.4, locate and identify the structures listed in the caption. Relate these structures with those labeled a to i in the figure. Can you associate these with structures in your own skull? Jaw Muscle Attachments In this exercise you will learn to identify, locate the connecting points, and understand the function of masseter and temporalis muscles. The only materials required for this exercise are your fingers. < previous page

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Figure A.1. < previous page

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Page 241

Figure A.4. Match the following nine terms with the structures labeled a to i on the illustrated red fox skull. The structural terms are as follows: cheekbone, cranium, dentition, mandible, maxilla, sagittal crest, nasal structure, orbit or eye socket, and zygomatic arch. < previous page

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Page 242 The Masseter Muscle Place your fingers along the back side of your jaw. Now, making exaggerated movements with your jaw, open and close your mouth. Clench your teeth. The muscle moving beneath your fingertips is the masseter muscle. While continuing to move your jaw, find the limits of this muscle's movement. Moving up the side of your head, this muscle stops moving at the zygomatic arch. Moving down the side of your head, this muscle stops moving at the bottom of your lower jaw. Moving forward along your lower jaw, notice that this muscle stops moving at about half to one-third of the way along the mandible. The Temporalis Muscle Move your fingers to the side of your head directly above the back of your jaw, just above and behind your eyebrow. Now, making exaggerated movements with your jaw, open and close your mouth. The muscle moving and rippling beneath your fingertips is the temporalis muscle. While continuing to move your jaw, find the limits of this muscle's movement. Moving up the side of your head, this muscle stops moving at about eyebrow level between your eye socket and ear. Moving down the side of your head, this muscle can be felt moving until it passes behind the zygomatic arch. At this point its movement is cloaked by the movement of the masseter. Since temporalis muscles move only when the lower jaw moves, however, you can safely assume they connect to the rear portions of your lower jaw.

Tooth Identification In this exercise you will learn to identify your own teeth. A regular wall mirror or, preferably, a small hand-held mirror is all that's required. Use Figure 2.3 in chapter 2 to identify the four basic tooth groups: incisors, canines, bicuspids, and molars. Now go to a mirror, open your mouth wide, and examine the teeth of your lower jaw. If you have a hand mirror, move it so you can see the roof of your mouth and your upper teeth. Compare your teeth with those illustrated in Figure 2.3. Can you identify these teeth in your own mouth? Vision This exercise illustrates the properties of and differences between binocular and monocular vision. The only materials required are two cardboard tubes. < previous page

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Page 243 Binocular Vision Close one eye and rotate the open eye as far to the right and left as possible, then switch and repeat this procedure with the other eye. Open both eyes and notice that the vision of each eye overlaps. This overlap produces binocular vision. Now, with both eyes open look at some object in the room. Notice that it's easy to tell the distance this object is from you. This demonstrates the depth perception afforded by binocular vision. Monocular Vision Place one cardboard tube over each eye and angle the tubes away from each other. Notice that each eye sees a separate image and that the images do not overlap. This separation of viewed images produces monocular vision. Now, close one eye and with the other eye look through a tube at an object in the room. Notice the difficulty in determining the distance this object is from you. This exercise demonstrates the lack of depth perception associated with monocular vision. Jaw Strength This section uses jaw models to illustrate gripping strength associated with basic general herbivore and carnivore mandible structures. For this exercise you will need the following materials: An unbent paper clip or straight pin. A pair of scissors.

A roll of tape. A flat, one-square-foot piece of corrugated cardboard. A rubber band. A quarter. From cardboard cut out the jaw shapes and notches as shown in Figure A.5. The labels in this figure mean the following: a) The left side of the upper jaw b) The right side of the upper jaw c) The center of the upper jaw d) An outline shape of a flat herbivore lower jaw e) An outline shape of a curved carnivore lower jaw f) The notch for muscle attachment in the lower jaws g) A notch for the attachment of the temporalis muscle h) A notch for the attachment of the masseter muscle < previous page

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Page 244 The same upper jaw will be used for both herbivore and carnivore mock jaws. Using their relative shapes, align the left, center, and right pieces of the mock upper jaw. Glue or tape the pieces together. As shown in Figure A.6, insert the herbivore jaw (d) into the upper jaw. Take a straightened paper clip or straight pin and push it through the cardboard at the position marked by the black dot. This is where the lower jaw and upper jaw meet. Since the masseter muscle is the major jaw muscle in herbivores, fit a rubber band into notch (f) on the lower jaw and notch (h), the masseter anchor position in the upper jaw. The rubber band should be snug but not too tight. As shown in Figure A.7, insert the carnivore jaw (e) into the cardboard representation of the upper jaw. Take a straightened paper clip or straight pin and push it through the cardboard where the lower jaw and upper jaw meet. To represent the temporalis, the major jaw muscle in carnivores, fit a rubber band into notch (f) on the lower jaw and notch (g), the temporalis anchor position in the upper jaw. Again, the rubber band should not be too tight. Place a quarter between the mock jaws at the front where they

Figure A.5. The pieces needed for the construction of two mock jaws. < previous page

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Figure A.6. Diagram of cardboard outline of a herbivore lower jaw. come together. Turn the jaws over so they're facing down. How easily does the quarter fall out? The curved jaw and temporalis muscle, as in carnivores, provide sufficient power to the front of the jaws to hold the quarter securely. The quarter should remain held even with a few shakes. The flat jaw and masseter muscle, as in herbivores, provide less power to the front of the jaws. The quarter will fall out either by its sheer weight or with a few slight shakes. Experiment with tightening the rubber band on both structures. How loose does the rubber band have to be to drop the quarter from the mock carnivore jaw? How tight does the rubber band have to be to securely hold the quarter in the mock herbivore jaw?

Figure A.7. Diagram of cardboard outline of a carnivore lower jaw. < previous page

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Page 246 Answers to Earlier Exercises In the exercise on skull classification the four skulls illustrated in Figures A.1A.3 are the following: a) A carnivore (spotted skunk) b) A herbivore (woodchuck) c) A herbivore (moose) In the exercise on skull structure identification the structures marked in Figure A.4 are as follows: a) Orbit, or eye socket b) Cheekbone c) Mandible d) Cranium e) Zygomatic arch f) Sinus cavity g) Dentition h) Maxilla i) Sagittal crest < previous page

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Page 247 Appendix B Scientific Terms and Common Names The origins of terms used in scientific nomenclature are many and varied. While primarily of Latin derivation, many words also descend from Greek, German, Swedish, French, Spanish, Italian, and English. Latin is the root for many Western languages such as French and Italian and can be understood by many people. Languages do not remain stable throughout history. At different ages a language takes on distinctive styles, forms, and patterns of speech. This is why languages are divided into different categories, each based on the time periods during which certain styles and forms of speech were common. For example, modern English and German differ dramatically from those spoken 500 years ago. Middle English was spoken from 13001475 a.d. and Old English was spoken from 7001000 a.d. The German language, too, has been divided into the different ages of Middle German and Old High German. Since words are formed during various periods in a language's development, this historical division of usage creates an important guide for determining the relative genealogy of words or terms. Scientific Terms The following scientific names were used in the text of this book. They are listed in this section along with their language origins.

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Page 248 BovidaeA family name, this term is derived from the Latin word bos, which means head of cattle. CaballusA species name, this term is taken from the Spanish word caballa, meaning horse. Canidae and CanisFamily and genus names respectively, these words are derivations from the Latin words caninus and canis, which mean of or relating to dogs or the dog family. CervidaeA family name, this term is derived from the Latin word cervinus, which means of a deer. EquidaeA family name, this term is derived from the Latin word equinus and the French word equus, which mean of or related to a horse. Felidae and FelisFamily and genus names respectively, these terms are derived from the Latin words felinus and fetis, which mean of or relating to cats or the cat family. HomoA genus name, this term is the Latin word for man. InsectivoraAn order name, this term is derived from the Latin word insectus. PerissodactylaAn order name, this term is derived from the Greek word perissos, meaning excessive or odd in number, and daktylos, which means finger or toe. Procyonidae and ProcyonFamily and genus names respectively. These terms are derived from the Greek word Prokyon, which means foredog or rising before the Dog Star.

RodentiaAn order name for rodents. RuminantiaA suborder name for ruminants. SapienA species name, this term is Latin for wise and intelligent. ScrofaA species name, this term is Latin for breeding sow. SusA genus name, this term is Latin for pig, swine, or hog. UngulataAn order name for ungulates. Ursidae and UrsusFamily and genus names respectively, these terms are taken from the Latin word ursus, which means bear. Common Names The following common names were presented in the text of this book. They are listed in this section along with their language origins. ArmadilloTaken from the Latin word armatus and the Spanish word armado, which mean armed one. < previous page

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Page 249 BatAn alteration of the Middle English word bakke, which, in turn, probably had its origin in the Old Swedish word nattbakka, or bat. BearDerived from the Middle English word here, the Old English bera, and is akin to the Old English word brun, which means brown. BovineTaken from the Latin words bovinus and bos, which mean ox or cow. CanineDerivation of the Latin words caninus and canis, which mean of or relating to dogs or the dog family. CarnivoreDerived from the Latin word carnivorus, which means flesh-eating animals. CatDerived from the Latin words cattus and catta, the Old English word catt, and the Old High German word kazza. DonkeyDerived from the Middle and Old English word dunn, which means dull, drab, or having a neutral, slightly brownish dark gray appearance. DogA Middle English word that has been passed down to the present day. It is derived from the Old English word docga. HerbivoreThis term is derived from the Latin word herbivora, which means plant-eating mammals. HorseThis name is derived from the Middle English word hors and the Old High German word hros, both of which mean horse. HumanThis word is derived from the Latin words humanus and

homo, which mean man, and/or relating to the characteristics of man. OmnivoreDerived from the Latin word omnivorus, which means feeding on both plants and the flesh of animals. PigThis term is often attributed to the Middle English word pigge. RodentThis term comes from the Latin words rodens and rodere, which mean to gnaw. SwineThis name is taken from the Old English and Old High German word swin, which means pig. UngulateDerived from the Latin word ungulatus, which means having hooves. < previous page

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Page 251 Appendix C Scientific Classification This appendix lists the common names of animals and their taxonomic classification ranks of order, family, genus, and species. Order: Artiodactyla FAMILY GENUS Bovidae Bison

SPECIES bison

Buffalo (bison): Domestic Bovidae Ovis aries sheep: Domestic Bovidae Oreamnos americanus goat: Ox (cow): Bovidae Bos taurus PronghornAntilocapridaeAntilocapra americana antelope: Elk: Cervidae Cervus canadensis Moose: Cervidae Alces alces Mule Cervidae Odocoileus hemionus deer: Cervidae Odocoileus virginianus Whitetailed deer: Domestic Suidae Sus scrofa pig: Collared Tayassuidae Tayassu taiacu

peccary:

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Page 252 Order: Carnivora FAMILY GENUS SPECIES Canidae Canis familiaris

Domestic dog: Coyote: Canidae Canis latrans Gray wolf: Canidae Canis lupus Fox: Canidae Vulpes vulpes Domestic Felidae Felis catus cat: Cougar: Felidae Felis concolor Lynx: Felidae Lynx lynx Bobcat: Felidae Lynx rufus les European Mustelidae Meles badger: Mink: Mustelidae Mustela vison Marten: Mustelidae Martes americana Pine Mustelidae Martes martes marten: River Mustelidae Lutra canadensis otter: Striped Mustelidae Mephitis mephitis skunk: LongMustelidae Mustela nata tailed weasel: Wolverine: Mustelidae Gulo luscus Raccoon: Procyonidae Procyon lotor

Brown bear Black bear: Grizzly bear: Polar bear:

Ursidae

Ursus

arctos

Ursidae

Ursus americanus

Ursidae

Ursus

Ursidae

Ursus maritimus

horribilis

Order: Chiroptera FAMILY GENUS SPECIES VespertilionidaeEptesicus fuscus

Big brown bat: Little Vespertilionidae Myotis lucifugus brown bat: Cave Vespertilionidae Myotis velifer bat:

Order: Didelphiidae FAMILY GENUS SPECIES Opossum:DidelphidaeDidelphisvirginiana

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Page 253 Order: Insectivora FAMILY GENUS SPECIES Eastern Talpidae Scalopus aquaticus mole: Elephant SoricidaeElephantulus rozeti shrew: Common Soricidae Sorex araneus shrew: Order: Lagomorpha FAMILY GENUS SPECIES American Leporidae Lepus americanus hare: Desert Leporidae Sylvilagus auduboni cottontail: Eastern Leporidae Sylvilagus floridanus cottontail: Nuttall's Leporidae Sylvilagus nuttallii cottontail: European LeporidaeOryctolagus cuniculus rabbit: Order: Rodentia FAMILY GENUS Muridae Mus

SPECIES musculus

House mouse: Plains Muridae Mus flavescens mouse: Brown rat: Muridae Rattus norvegicus Colorado Sciuridae Eutamias quadrivittatus chipmunk: Wyoming Sciuridae Spennophilus elegans Eastern Sciuridae Sciurus carolinensis ground gray squirrel: squirrel: Beaver: Castoridae Castor canadensis Woodchuck: Sciuridae Marmota monax SoutheasternGeomyidae Geomys pinetis Porcupine:ErethizontidaeErethizon dorsatum pocket gopher:

Order. Perisscdactyla FAMILY GENUS SPECIES Donkey: Equidae Equidae Equus Horse: Equus asinus caballus

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Page 254 Order: Primate FAMILY GENUS SPECIES Human: Homonidae Homo sapiens Order: Xenartha* FAMILY GENUS SPECIES Armadillo:DasypodidaeDasypusnovemcinctus * Xenartha is the new name for the order in which the armadillo resides. Edentata was the old name.

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Page 255 Appendix D Suppliers Not everyone desires or has time to collect specimens from the wild. This situation may be particularly true for those involved in science education. The following companies offer alternative sources for skeletal specimens, biological teaching supplies, and science-related equipment. Contact these organizations directly to receive information regarding price structures, specimen variety, and related materials. Note that addresses and phone numbers are subject to change. Accent Science P.O. Box 1444 Saginaw, MI 48605 (517) 799-8103 Acorn Naturalists 17300 East 17th Street Suite J-236 Tustin, CA 92680 (714) 838-4888 (800) 422-8886 Adventures Company 435 Main Street Johnson City, NY 13790 (607) 729-6512 (800) 477-6512

American Science and Surplus 3605 Howard Street Skokie, IL 60076 (708) 982-0870 < previous page

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Page 256 Analytical Scientific 11049 Bandera Road San Antonio, TX 78250 (210) 684-7373 (800) 364-4747 Ben Meadows Company 3589 Broad Street Chamblee, GA 30341 (800) 241-6401 The Biology Store P.O. Box 2691 Escondido, CA 92033 (619) 745-1445 Carolina Biological Supply Company 2700 York Road Burlington, NC 27215 (910) 584-0381 Central Scientific Company (CENCO) 3300 CENCO Parkway Franklin Park, IL 60131 (708) 451-0231 (800) 262-3620 CHEMetrics, Inc. Route 28 Calverton, VA 22016-0214

(703) 788-9026 (800) 356-3072 Chem Scientific, Inc. 67 Chapel Street Newton, MA 02158 (617) 527-6626 Connecticut Valley Biological Supply Company, Inc. 82 Valley Road P.O. Box 326 South Hampton, MA 01073 (800) 628-7748 Creative Teaching Associates P.O. Box 7766 Fresno, CA 93747 (209) 291-6626 Cuisenaire Company of America 10 Bank Street White Plains, NY 10606 (914) 997-2600 (800) 237-3142 Delta Education, Inc. P.O. Box 915 Hudson, NH 03051-0915 (603) 889-8899 (800) 258-1302 Edmund Scientific Company 101 East Gloucester Pike Barrington, NJ 08007

(609) 573-6270 Educational Instruments, Inc. 11 Robinson Lane Oxford, CT 06483 (203) 888-1266 Etgen's Scientific Stuff 3600 Whitney Avenue Sacramento, CA 95821 (916) 972-1871 < previous page

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Page 257 Fisher ScientificEMD 4901 West LeMoyne Avenue Chicago, IL 60651 (312) 378-7770 (800) 955-1177 Flinn Scientific, Inc. 131 Flinn Street P.O. Box 219 Batavia, IL 60510 (800) 452-1261 Forestry Suppliers, Inc. 205 West Rankin Street P.O. Box 8397 Jackson, MS 39284-8397 (601) 354-3565 (800) 647-5368 Frey Scientific 905 Hickory Lane Mansfield, OH 44905 (800) 225-3739 Grau-Hall Scientific 64016501 Elvas Avenue Sacramento, CA 95819 (916) 455-5258 (800) 331-4728

Hawks, Owls, and Wildlife RD#1, Box 293 Buskirk, NY 12028 (518) 686-4080 Hubbard Scientific, Inc. 3101 Iris Avenue Suite 215 Boulder, CO 80301 (303) 443-0020 (800) 446-8767 Kons Scientific Company, Inc. P.O. Box 3 Germantown, WI 53022-0003 (414) 242-3636 Learning Alternatives 2370 West 89A Suite #5 Sedona, AZ 86336 (602) 204-2172 (800) 426-3766 Learning Things 68A Broadway P.O. Box 436 Arlington, MA 02174 (617) 646-0093 NASCO P.O. Box 901 Fort Atkinson, WI 53538-0901

(414) 563-2446 (800) 558-9595 NASCO Modesto P.O. Box 3837 Modesto, CA 95352 (209) 529-6957 (800) 558-9595 < previous page

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Page 258 National Teaching Aids, Inc. 1845 Highland Avenue New Hyde Park, NY 11040 (516) 326-2555 National Wildlife Federation 1400 16th St., N.W. Washington, DC 20036-2266 (703) 790-4233 Nature Discoveries 389 Rock Beach Road Rochester, NY 14617 (716) 865-4580 Nebraska Scientific A Division of Cygrus Company, Inc. 3823 Leavenworth Street Omaha, NE 68105-1180 (402) 346-7214 (800) 228-7117 Northwest Laboratories, Inc. #20-255 Great Arrow Drive Buffalo, NY 14207 (716) 877-4748 Northwest Scientific Supply Company, Inc. 4311 Anthony Court, #700 P.O. Box 305

Rocklin, CA 45677 (916) 652-9229 Nurnberg Scientific Company 6310 S.W. Virginia Avenue Portland, OR 97201 (503) 246-8297 Parco Scientific Company Instrument Group 316 Youngstown-Kingsville Road, S.E. P.O. Box 189 Vienna, OH 44473 (216) 394-1100 (800) 247-2726 Sargent-Welch Scientific Company P.O. Box 1026 Skokie, IL 60076-8026 (800) 727-4368 Scavengers Scientific Supply Company P.O. Box 240009 Dougals, AK 99824 Schoolmasters Science 745 State Circle P.O. Box 1941 Ann Arbor, MI 48106 (313) 761-5072 Science Kit and Boreal Laboratories 777 East Park Drive Tonawanda, NY 14150

(800) 828-7777 SCI-MA Education, Inc. 325 South Westwood, #4 Mesa, AZ 85210 (602) 464-5605 < previous page

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Page 259 Skullduggery 624 South B Street Tustin, CA 92680 (714) 832-8488 Skulls Unlimited International P.O. Box 6741 Moore, OK 73153 (405) 632-4200 (800) 676-7585 Summit Learning P.O. Box 493 Fort Collins, CO 80522 (800) 777-8817 WARD'S Natural Science Establishment, Inc. 5100 West Henrietta Road P.O. Box 92912 Rochester, NY 14692-9012 (716) 359-2502 (800) 962-2660 < previous page

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Page 261 Appendix E Societies and Associations The organizations listed in this appendix are involved with environmental studies, education, and conservation efforts. Many, as can be seen by perusing the publications section of the bibliography, publish their own journals. For information regarding membership and environment-related topics, contact these groups directly. You could also contact natural history museums, colleges, and local, regional, state, and government environmental agencies. United States AAAS/Project 2061 c/o Oxford University Press 200 Madison Avenue New York, NY 10016 American Association for the Advancement of Science (AAAS) 1333 H Street, NW Washington, DC 20005 American Birding Association, Inc. P.O. Box 6599 Colorado Springs, CO 80934 The American Nature Study 5881 Cold Brook Road Homer, NY 13077

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Page 262 American Society of Mammalogists c/o State University of New York at Oswego Department of Biology Oswego, NY 13126 Biological Sciences Curriculum Study (BSCS) 830 North Tejon Street, Suite 405 Colorado Springs, CO 80903-4720 Colorado Division of Wildlife 6060 Broadway Denver, CO 80216 Colorado Wildlife Federation 7475 Dakin Street, Suite 137 Denver, CO 80221 Ecological Society of America Center for Environmental Studies Arizona State University Tempe, AZ 85287 Ethical Science Education Coalition P.O. Box 16736 Stamford, CT 06905 Fish and Wildlife Reference Service 5430 Grosvenor Lane, Suite 110 Bethesda, MD 20814-2158 National Audubon Society

950 Third Avenue New York, NY 10022 National Geographic Society 1145 17th Street, NW Washington, DC 20036 National Resources Information Council (NRIC) 317 West Prospect Fort Collins, CO 80526-2097 National Science Teachers Association Executive Office 1840 Wilson Boulevard Arlington, VA 22201-3000 National Wildlife Federation 1412-16th Street, NW Washington, DC 20036 The Nature Conservancy International Headquarters 1815 North Lynn Street Arlington, VA 22209 NYZS/ The Wildlife Conservation Society The Bronx New York, NY 10460 The Scientist Center for Animal Welfare 4805 St. Elmo Avenue Bethesda, MD 20814

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Page 263 Sierra Club 730 Polk Street San Francisco, CA 94109 Society for Conservation Biology c/o Blackwell Scientific Publications, Inc. 238 Main Street Cambridge, MA 02142 Society of Systematic Biologists c/o National Museum of Natural History NHB163 Washington, DC 20560 Society of Systematic Zoology c/o Smithsonian Institution Department of Invertebrate Zoology NMNH Washington, DC 20560 The Southwestern Association of Naturalists c/o Southwest Texas State University Department of Biology 601 University Drive San Marcos, TX 78666 The Wildlife Society 5410 Grosvenor Lane Bethesda, MD 20814-2197 World Wildlife Fund

1250 24th Street, NW Washington, DC 20037 Overseas Administration de la Recherche Agronimique Manhattan Center 7e etage Avenue du Boulevard 21 B-1210 Bruxelles Belgium Agricoltura Ufficio delle Relazioni internazionali 18, via XX Settembre I-00187 Roma Italy Animal Behavior Society Reproduction Research Information Service 141 Newmarket Road Cambridge CB5 8HA United Kingdom The Association for the Study of Animal Behaviour Reproduction Research Information Service 141 Newmarket Road Cambridge CB5 8HA United Kingdom Australian Rangland Society P.O. Box 596 Alice Springs, NT 0871 Australia

Centre Naturopa BP 431 R6, F-67006 Strasbourg France < previous page

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Page 264 Department des Affaires Etrangeres Contrada Omerelli Palazzo Begni Via Giacomini 47031 San Marino Deutscher Naturschutzring E. V. Kalkuhlstrasse 24 Postfach 32 02 10 D-5300 Bonn-Oberkassel 3 Germany Direction de la Protection de la Nature 14, Boulevard du General-Leclerc F-92524 Neuilly-sur-Seine Cedex France English Nature Northminster House GB-Peterborough PE1 1UA United Kingdom Hellenic Society for the Protection of Nature 24, Rue Nikis GR-10557 Athenes Greece Liechtensteinische Gesellschaft fur Umweltschutz Heiligkreuz 52

FL-9490 Vaduz Liechtenstein Liga para a Proteccao da Natureza Estrada do Calhariz de Benfica, 187 P-1500 Lisboa Portugal Ligue Suisse pour la Protection de la Nature Wartenbergstrasse 22 CH-4052 Bale Switzerland Ministerio de Obras Publicas y Urbanismo Paseo de la Castellana 67 E-28071 Madrid Spain Ministry of Agriculture and Fisheries Department for Nature Conservation Environmental Protection and Wildlife Management P.O. Box 20401 NL-2500 Ek's-Gravenhage The Netherlands Ministry of the Environment M-Beltissebh Malta Ministry of the Environment Myntgaten 2 P.O. Box 8013 DEP N-0030 Oslo1 Norway

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Page 265 Ministry of the Environment The National Forest and Nature Agency Slotsmarken 13 DK-2970 Horsholm Denmark Ministry of the Environment 5A Rue de Prague L-Luxembourg-Ville Luxembourg Ministry of the Environment P.O. Box 351 H-1394 Budapest Hungary Ministry of the Environment P.O. Box 399 SF-00121 Helsinki Finland National Swedish Environment Protection Board P.O. Box 1302 S-17125 Solna Sweden Nature Conservation Council Hlemmur 3 P.O. Box 5324 ISL-125 Reykjavik

Iceland Nature Conservation Service Ministry of Agriculture and Natural Resources CY-Nicosia Cyprus Naturopa-Zentrum Austria Stiftgasse 16 Swarovski-Haus, 2. Stock A-6020 Innsbruck Austria Turkish Association for the Conservation of Nature and Natural Resources Menekse Sokak 29/4 Kizilay TR-Ankara Turkey U.K. Joint Nature Conservation Committee Monkstone House GB Peterborough United Kingdom PE1 1JY Wildlife Service Office of Public Works Leeson Lane IRL-Dublin 2 Ireland < previous page

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Page 267 Recommended Reading Books Allaby, Michael, ed. The Concise Oxford Dictionary of Zoology. Oxford: Oxford University Press, 1991. Anderson, Rudolph M. Methods of Collecting and Preserving Vertebrate Animals. National Museum of Canada, Bulletin No. 69, Biological Series No. 18, 1948 Anderson, Sydney, and J. Knox Jones, Jr., eds. Recent Mammals of the World: A Synopsis of Families. New York: The Ronald Press Co., 1967. Banfield, A. W. F. The Mammals of Canada. Toronto: University of Toronto Press, 1974. Barbour, R. W., and W. H. Davis. Bats of America. Kentucky: The University Press of Kentucky, 1969 Blackwelder, Richard E. Taxonomy: A Text and Reference Book. New York: John Wiley and Sons, 1967. Burt, William H., and Richard P. Grossenheider. A Field Guide to Mammals. The Peterson Field Guide Series. Boston: Houghton Mifflin Company, 1983. < previous page

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Page 268 Checklist of Vertebrates of the United States, the U.S. Territories, and Canada. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service, Resource Publication 166, 1987. Cosgrove, Margaret. Bone for Bone. New York: Dodd, Mead and Company, 1968. DeBlase, Anthony F., and Robert E. Martin. A Manual of Mammalogy: With Keys to Families of the World. Dubuque, Iowa: William C. Brown Company Publishers, 1981. Gittleman, John L., ed. Carnivore Behavior, Ecology, and Evolution. Ithaca, N.Y.: Comstock Publishing Associates (Cornell University Press), 1989. Glass, Bryan P. A Key to the Skulls of North American Mammals. 2nd ed. Stillwater, Okla.: Oklahoma State University, 1973. Gotch, A. F. Mammals: Their Latin Names ExplainedA Guide to Animal Classification. Poole Dorset, U.K.: Blandford Press Ltd., 1979. Gould, Stephen Jay. Ever since Darwin: Reflections in Natural History. New York: W. W. Norton and Company, 1977. . The Flamingo's Smile: Reflections in Natural History. New York: W. W. Norton and Company, 1985. . Hen's Teeth and Horse's Toes: Reflections in Natural History. New York: W. W. Norton and Company, 1983. . The Panda's Thumb: Reflections in Natural History. New York: W. W. Norton and Company, 1985.

Grant, Lesley. Discover Bones: Explore the Science of Skeletons. Reading, Mass.: Addison-Wesley Publishing Co., 1992. Grzimek, H. C. Bernhard. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold, 1978. Hall, Raymond E. The Mammals of North America, 2nd ed. 2 vols. New York: John Wiley and Sons, 1981. Hildebrand, Milton. Analysis of Vertebrate Structure. New York: John Wiley and Sons, 1974. Honachi, James, Kenneth Kinman, and James Koeppl, eds. Mammal Species of the World: A Taxonomic and Geographic Reference. Lawrence, Kans.: Allen Press, Inc., and The Association of Systematic Collections, 1982. Jones, J. Knox, Jr., and Richard W. Manning. Illustrated Key to Skulls of Genera of North American Land Mammals. Lubbock, Tex.: Texas Tech University Press, 1992. < previous page

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Page 269 Livaudias, Madeleine, and Robert Dunne. The Skeleton Book: An Inside Look at Animals. New York: Walker Publications, 1972. Malam, John, and John Creming. Dinosaur Skeletons. New York: Dell Publishing, 1991. Matthiessen, Peter. Wildlife in America. New York: Viking Penguin, Inc., 1987. Mayer, Ernst. Principles of Systematic Zoology. New York: McGraw-Hill, 1969. Miller, Gerrit S., Jr., and Remington Kellogg. Smithsonian InstitutionList of North American Recent Mammals. Washington, D.C: U.S. Government Printing Office, 1955. Nowalk, Ronald M., and John L. Paradise. Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press, 1983. Parker, Steve. Skeleton. Eyewitness Books. New York: Alfred A. Knopf, 1988. Pasquini, Chris, and Tom Spurgeon. Anatomy of Domestic Animals: Systemic and Regional Approaches. La Porte, Colo.: SUDZ Publishing, 1967. Rose, Kenneth Jon. Classification of the Animal Kingdom: An Introduction to Evolution. New York: David McKay Company, Inc., 1980. Rothschild, Lord. A Classification of Living Animals. New York: John Wiley and Sons, 1961.

Rubenstein, Daniel I., and Richard W. Wranham, eds. Ecological Aspects of Social Evolution: Birds and Mammals. Princeton, N.J.: Princeton University Press, 1986. Spence, Alexander P., and Elliott B. Mason. Human Anatomy and Physiology. New York: The Benjamin/Cummings Publishing Company, Inc., 1979. Vaughan, Terry A. Mammalogy. Philadelphia: Saunders College Publishing, 1978. Weisz, Paul B. The Science of Zoology. 2nd ed. New York: McGraw-Hill, 1973. Whitfield, Philip. The Hunters. New York: Simon and Schuster, 1978. World Wildlife Fund. The Official World Wildlife Fund Guide to Endangered Species of North America. 2 vols. Washington, D.C.: Beacham Publishing, Inc., 1990. Young, J. Z. The Life of Vertebrates. 3rd ed. Oxford: Oxford University Press, 1981. < previous page

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Page 270 Periodicals The American Midland Naturalist. University of Notre Dame, Notre Dame, IN 46556. Animal Behaviour. Academic Press Ltd., High Street, Foots Cray Sidcup, Kent DA14 5HP, United Kingdom. Colorado Outdoors. Colorado Department of Natural Resources, Division of Wildlife, 6060 Broadway, Denver, CO 80216. Ecological Applications. Ecological Society of America, Center for Environmental Studies, Arizona State University, Tempe, AZ 85287. Ethics in Research on Animal Behavior. Academic Press Ltd., High Street, Foots Cray Sidcup, Kent DA14 5HP, United Kingdom. The Great Basin Naturalist. 290 MLBM, Brigham Young University, Provo, UT 84602. International Wildlife. National Wildlife Federation, 1412 16th Street, NW, Washington, DC 20036. The Journal of the Society for Conservation Biology. Blackwell Scientific Publications, Inc., 238 Main Street, Cambridge, MA 02142. The Journal of Wildlife Management. The Wildlife Society, 5410 Grosvenor Lane, Bethesda, MD 20814-2197. National Wildlife. National Wildlife Federation, 1412 16th Street, NW, Washington, DC 20036.

Natural History. American Museum of Natural History, Central Park West at 79th Street, New York, MY 10024. Nature: International Weekly Journal of Science. Macmillion Magazines, Ltd., 4 Little Essex Street, London, WC2R 3LF, United Kingdom. Nature: International Weekly Journal of Science. Macmillion Magazines, Ltd., P.O. Box 1733, Riverton, NJ 08077-7333. Nature Canada. Canadian Nature Federation, 1 Nicholas Street, Suite 520, Ottawa, Ontario, Canada K1N 7B7. Nature Conservancy Magazine. Nature Conservancy, 1815 North Lynn Street, Arlington, VA 22209. Nature Study Journal. The American Nature Study, 5881 Cold Brook Road, Homer, NY 13077. Naturopa. Centre Naturopa of the Council of Europe, BP 431 R6, F67006 Strasbourg, Cedex, France. The Rangeland Journal. Australian Rangeland Society, P.O. Box 596. Alice Springs, NT 0871, Australia. Ranger Rick. National Wildlife Federation, 1412 16th Street, NW, Washington, DC 20036. < previous page

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Page 271 Science. American Association for the Advancement of Science, 1333 H Street, NW, Washington, DC 20005. The Science Teacher. National Science Teachers Association (NSTA), 1840 Wilson Boulevard, Arlington, VA 22201-3000. Scientific American. Scientific American, Inc., 415 Madison Avenue, New York, NY 10017-1111. The Southwestern Naturalist. The Southwestern Association of Naturalists, Southwest Texas State University, Department of Biology, 601 University Drive, San Marcos, TX 78666. Systematic Biology. Society of Systematic Biologists, c/o National Museum of Natural History, NHB163, Washington, DC 20560. Systematic Zoology. Society of Systematic Zoology, c/o Smithsonian Institution, Department of Invertebrate Zoology, NMNH, Washington, DC 20560. < previous page

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Page 273 Index A Acetabulum, 149, 151, 152, 153, 227 Acromian process, 134, 135 Anthrax, 213, 227 Articular process, 158, 159, 160, 227 B Bacteria Bacillus anthracis, 213, 227 Clostridium botulinum, 210, 229 Clostridium tetani, 212 Pasteurella pestis, 213, 232 Badger, profile of, 182-185 Ball-and-socket joint, 152, 153 Bat, profile of, 185-187 Behavior, skeletal interpretation of carnivore, 181-87 herbivore, 188-94 omnivore, 194-201

Bicuspid, 18, 20, 24, 27, 228 Binocular vision, 36, 37, 38, 39, 228, 243 Biped, 98, 152, 153, 174, 179, 228 Black Death, 212-213 Blood poisoning, 210, 228 Bone cleaning home use, 215-23 kit, 216 methods, 217-22, 223-25 museum use, 223-25 preparation, 217 sealing, 222 Bone collecting ethics, 203-04 gear, 230 methodology, 204-08 precautions, 208-14 Botulism, 210-12, 228 Breastbone, 132, 174, 175, 228 Bubonic plague, 212-13, 228 C

Canine teeth, 18, 20, 21, 24, 26, 27, 228 Carnassial, 20, 228 Carnivore, 2, 10, 11, 106, 107, 108, 109, 112, 114, 132, 135, 153, 167, 178, 180, 228 behavioral interpretation, 181-87 < previous page

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Page 274 crania, 43 dentition, 19-21 environmental lifestyle, 2, 11, 51, 181 jaws, 29, 43-44 jaw strength, 243-44 nasal cavity, 30 orbits, 38 skull illustrations, 51-66 zygomatic arch, 40 Carpal bones, 103, 104, 105 Cat, profile of, 181-82, 183 Caudal vertebrae, 165, 228 Cervical vertebrae, 161-63, 170, 172, 228 Cheekbone, 39, 228 Classification systems, 3-15 inferential, 1, 3, 9-15 Linnaean, 4, 231 systematics, 3, 234 taxonomy, 3-9, 234 Clavicle, 132, 134, 229

Claw, 101, 105, 106, 107-112 non-retractable, 107, 111 retractable, 110, 111 Collarbone, 132, 134, 229 Common names, 8-9, 248-49 Convergent evolution, 10 Coracoid process, 134, 135 Costa cartilage, 174, 175, 177, 229 Cow, profile of, 190-92 Craniology, 16, 229 Cranium, 42-43, 229 bones of 42 carnivore, 43 herbivore, 43 omnivore, 43 shapes of, 42 Cutting blade teeth, 20 D Decomposition, 210, 229 Dentition, 17-28, 229 carnivore, 19-21

herbivore, 21-24 omnivore, 24-28 See also Teeth Depth perception, 36, 229 Dermestid beetles, 224-25, 229 Digits, 105, 106, 107 Digitigrade, 114, 229 Diseases, 210-13 anthrax, 213, 227 botulism, 210-212 bubonic plague, 212, 228 distemper, 212-13, 229 rabies, 212, 232 septicemia, 210, 233 tetanus, 212 Dog, profile of, 195-97 Double-curved spine, 165, 170, 172, 229 E Environmental lifestyle, 2, 9, 10-11, 16, 18, 19, 35, 43, 180 carnivore, 2, 11, 51, 181, 228 herbivore, 2, 11, 67, 188, 230

omnivore, 2, 11, 83, 194, 232 Eye socket, 35, 229 Eye teeth, 20, 229 F False pelvis, 149, 151, 230 False ribs, 175, 177, 230 Feet, posture during movement digitigrade, 114, 229 plantigrade, 114, 232 unguligrade, 114, 234 Femur, 123, 230 Fibula, 123, 230 Flat spine, 165, 167, 170, 171 Floating ribs, 175, 178, 230 Food poisoning, 210-12, 230 Functional morphology, 2, 230 G Girdles pectoral, 98 pelvic, 98, 101 shoulder, 132

Greater pelvis, 149 H Herbivore, 2, 10, 11, 106, 107, 108, 109, 112, 114, 132, 135, 153, 197, 170, 178, 180, 230, 249 < previous page

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Page 275 behavioral interpretation, 188-94 crania, 43 dentition, 21-24 environmental lifestyle, 2, 11, 67, 188 jaws, 30, 31, 32, 45-47, 243-244 nasal cavity, 30 orbits, 38-39 perissodactyl, 11, 21, 23, 26, 31, 41, 43, 45, 46, 67, 188 rodent, 11, 21, 22, 30, 32, 41, 43, 45, 47, 67, 181, 194 ruminant, 11, 21, 22, 31, 41, 43, 45, 46, 67, 191 zygomatic arch, 41 Hipbone, 148 See also Pelvis, structures of Home quality cleaning, 215-23, 230 Hooves, 101, 112-13 Horse, profile of, 188-90 Human, profile of, 199-201 Humerus, 114, 230 Humped-back spine, 165, 167-69 I

Ilium, 149, 230 Incisor, 17, 20, 22, 23, 26, 230 Inferential classification, 1, 3, 9-15 Inferior articular process, 158, 230 Intercostal space, 174, 177, 231 Intervertebral disk, 158, 160, 161, 231 Ischium, 152, 231 J Jaws, 28-30 carnivore, 29 herbivore, 30, 31, 32 masseter muscles of, 28, 43-48, 234 omnivore, 30, 33 temporalis muscles of, 28, 40, 43-48, 234 Jugal, 39, 231 L Leg bones, 98, 123, 124-31 femur, 123, 230 fibula, 123, 230 humerus, 114, 230 illustrations of, 115-22, 124-31

radius, 114, 232 ulna, 114, 234 tibia, 123 Lesser pelvis, 149 Limb groupings, 98-156 back, 13, 101, 102, 103 front, 13, 98, 100, 101 Linnaeus, Carolus, 4 Linnaean classification, 4, 231 Locomotion bipedal, 174, 179, 228 digitigrade, 114, 229 plantigrade, 114, 232 quadrupedal, 172, 179 unguligrade, 114, 234 Lockjaw, 212 Lower jaw, 28 Lumbar vertebrae, 164, 174, 231 M Maceration, 219-20, 231 Mandible, 20, 21, 28, 29, 30, 231, 243

Masseter, 28, 43-48, 231, 242, 243, 244 Maxilla, 20, 21, 22, 28, 231 Metacarpals, 105, 231 Metatarsals, 106, 231 Molars, 18, 21, 22, 23, 24, 27, 231 Monocular vision, 37, 38, 39, 231, 243 Museum quality cleaning, 223-225, 231 N Nails, types of, 106-113 claw, 101, 105, 106, 107-112 flat, 103, 112 hoof, 101, 112-13 Naming techniques common, 8-9, 248-49 taxonomic, 6-9, 247-48, 251-54 Nasal cavity, 30, 34 carnivore, 30 herbivore, 30 omnivore, 34 < previous page

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Page 276 O Omnivore, 2, 10, 11, 83, 97, 108, 109, 112, 114, 132, 135, 153, 197, 170, 178, 180, 232, 249 behavioral interpretation, 194-201 crania, 43 dentition, 24-28 environmental lifestyle, 2, 11, 83, 194 jaws, 30, 33, 45-48, 243-44 nasal cavity, 34 orbits, 39 skull illustrations, 83-97 zygomatic arch, 41 Orbit, 35-39, 232 carnivore, 38 herbivore, 38-39 omnivore, 39 Osteology, 223, 232 P Parietal bones, 42, 232 Pectoral girdle, 98, 132, 134-48, 232

Pelvic girdle, 98, 101, 148-53, 232 illustrations, 154-56 Pelvis, structures of, 149-53 acetabulum, 149, 151, 152, 153, 227 ball-and-socket joint, 152, 153 false pelvis, 149, 151, 230 greater pelvis, 149 ilium, 149, 230 ischium, 152, 231 lesser pelvis, 149 true pelvis, 149, 151, 234 Peripheral vision, 37 Perissodactyl, 11, 21, 26, 41, 43, 67, 188, 232, 248 dentition, 23, 24 jaws, 31, 45, 46 Phalanges, 105, 106, 232 Phalanx bones distal, 105, 106, 229 middle, 105, 106 proximal, 105, 106 Pig, profile of, 197-99

Plantigrade, 114, 232 Premolars, 20, 232 Q Quadruped, 152, 172, 179 R Rabbit, profile of, 192-94 Rabies, 212, 232 Radius, 114, 232 Ribs, 174-179 arrangement of, 175-78 false ribs, 175, 177, 230 floating ribs, 175, 178, 230 true ribs, 175, 177, 234 vertebral ribs, 175, 178, 235 vertebrochondral ribs, 175, 178, 235 vertebrosternal ribs, 175, 178, 235 Rib cage, 174, 232 Rodent, 11, 21, 30, 32, 67, 181, 194, 233, 248, 249 crania, 43 dentition, 22 jaws, 3, 45, 47

orbits, 38 zygomatic arch, 41 Ruminant, 11, 21, 41, 43, 67, 191, 233, 248 dentition, 22, 23 jaws, 31, 45, 46 S Sacral vertebrae, 164, 170, 172, 233 Sacrum, 148, 164, 166, 233 Sagittal crest, 42, 233 Scapula, 132-48, 233 common shapes, 134-36 illustrations of, 135-48 structures of, 134, 135 Septicemia, 210, 233 Sheep, profile of, 190-92 Shoulder blade, 132, 233 See also Scapula Shoulder girdle, 132 Skeleton disarticulated, 223 ligamentary, 223

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Page 277 Skull structures, 16-49 cranium, 42-43, 229 dentition, 17-28, 229 illustrations, 51-97 jaw, 28-30, 31-33 nasal bone, 30, 34 orbits, 35-39, 232 zygomatic arch, 39-41, 235 Spine, 157, 233 Spinal column, 165, 167, 174 Spinal cord, 157, 233 Spinal curvature, 165-70 double-curved spine, 165, 170, 172, 229 flat, 165, 167, 170, 171 humped-back, 165, 167-69 Spinous process, 158, 174, 233 Squamosal, 39 Sternum, 132, 174, 175, 177, 233 Superior articular process, 158, 233 Sutures, 16, 233

Systematics, 3, 234 T Tarsal bones, 103, 104, 234 Taxa, 4, 234 Taxonomic classification, 4-9 naming, 6-8, 247-48 nomenclature, 251-54 ranks, 4, 5, 6 Taxonomy, 3-9, 234 Teeth, 18-27 bicuspid, 18, 20, 24, 27, 228 canine, 18, 20, 21, 24, 26, 228 carnassial, 20, 228 cutting blade, 20 eye teeth, 20, 229 incisor, 17, 20, 22, 23, 26, 230 molar, 18, 21, 22, 23, 24, 27, 231 premolar, 20, 232 wolf's teeth, 21 Temporalis, 28, 40, 43-48, 234, 237, 242, 243, 244 Tetanus, 210

Tetrapods, 98, 234 Thoracic vertebrae, 164, 174, 234 Thorax, 174, 234 Tibia, 123 Transverse process, 158, 174, 234 True pelvis, 149, 151, 234 True ribs, 175, 177, 234 U Unguligrade, 114, 234 Ulna, 114, 234 Upper jaw, 28 V Vertebra, structures of, 157-65, 166 body, 158, 234 cap, 161, 235 foramen, 157, 235 inferior articular process, 158, 230 spinous process, 158, 174, 233 superior articular process, 158, 233 transverse process, 158, 174, 234 Vertebral groupings, 161-74

caudal, 165, 228 cervical, 161-63, 228, 170, 172 lumbar, 164, 174, 231 sacral, 164, 170, 172, 233 thoracic, 164, 174, 234 Vertebral column, 157-74, 235 Vertebral ribs, 175, 178, 235 Vertebrochondral ribs, 175, 178, 235 Vertebrosternal ribs, 175, 178, 235 Vision binocular, 36, 37, 38, 228 monocular, 37, 38, 39, 231 peripheral, 37 W Weight estimation, 123, 132, 133 Z Zygomatic arch, 39-41, 235 carnivore, 40 herbivore, 41 omnivore, 41 structures of, 39

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