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Megalodon Fact or Fiction?
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creature scene investigation
Megalodon Fact or Fiction?
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creature scene investigation Bigfoot: Fact or Fiction? Giant Anaconda and Other Cryptids: Fact or Fiction? Kraken: Fact or Fiction? Loch Ness Monster: Fact or Fiction? Megalodon: Fact or Fiction? Mokele-mbembe: Fact or Fiction?
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creature scene investigation
Megalodon Fact or Fiction?
Rick Emmer
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MEGALODON: FACT OR FICTION? Copyright © 2010 by Infobase Publishing All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information, contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Emmer, Rick. Megalodon: fact or fiction? / Rick Emmer. p. cm. — (Creature scene investigation) Includes bibliographical references and index. ISBN 978-0-7910-9777-9 (hardcover) ISBN 978-1-4381-3210-5 (e-book) 1. Carcharocles megalodon—Juvenile literature. I. Title. II. Series. QL89.2.C37E46 2010 567'.3—dc22 2009011461 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com. Text design by James Scotto-Lavino, Erik Lindstrom Cover design by Takeshi Takahashi Composition by EJB Publishing Services Cover printed by Bang Printing, Brainerd, MN Book printed and bound by Bang Printing, Brainerd, MN Date printed: March 2010 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. All links and Web addresses were checked and verified to be correct at the time of publication. Because of the dynamic nature of the Web, some addresses and links may have changed since publication and may no longer be valid.
Contents Preface
6
1 Megalodon: The Fisherman’s Nightmare
9
2 One Whale of a Fish Story 3 Like Father, Like Son 4 Things That Go Bump in the Night
24 36 43
5 A Long-Lost World 6 Mysteries from the Deep Blue Sea 7 Final Report: Megalodon
53 68 80
Glossary
86
Bibliography
92
Further Resources
96
Picture Credits
98
Index
99
About the Author
103
5
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PrefaCe
W
elcome to Creature Scene Investigation: The Science of Cryptozoology, the series devoted to the science of cryptozoology. Bernard Heuvelmans, a French scientist, invented that word 50 years ago. It is a combination of the words kryptos (Greek for “hidden”) and zoology, the scientific study of animals. So, cryptozoology is the study of “hidden” animals, or cryptids, which are animals that some people believe may exist, even though it is not yet proven. Just how does a person prove that a particular cryptid exists? Dedicated cryptozoologists (the scientists who study cryptozoology) follow a long, two-step process as they search for cryptids. First, they gather as much information about their animal as they can. The most important sources of information are people who live near where the cryptid supposedly lives. These people are most familiar with the animal and the stories about it. So, for example, if cryptozoologists want to find out about the Loch Ness Monster, they must ask the people who live around Loch Ness, a lake in Scotland where the monster was sighted. If they want to learn about Bigfoot, they should talk to people who found its footprints or took its photo. A cryptozoologist carefully examines all of this information. This is important because it helps the scientist identify and rule out some stories that might be mistakes or lies. The remaining information can then be used to produce a clear scientific description of the cryptid in question. It might even lead to solid proof that the cryptid exists. Second, a cryptozoologist takes the results of his or her research and goes into the field to look for solid evidence that the cryptid really exists. The best possible evidence would be 6
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Megalodon: The Fisherman’s Nightmare Preface
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an actual specimen—maybe even a live one. Short of that, a combination of good videos, photographs, footprints, body parts (bones and teeth, for example), and other clues can make a strong case for a cryptid’s existence. In this way, the science of cryptozoology is a lot like forensics, the science made famous by all of those crime investigation shows on TV. The goal of forensics detectives is to use the evidence they find to catch a criminal. The goal of cryptozoologists is to catch a cryptid—or at least to find solid evidence that it really exists. Some cryptids have become world-famous. The most famous ones of all are probably the legendary Loch Ness Monster of Scotland and the apelike Bigfoot of the United States. There are many other cryptids out there, too. At least, some people think so. This series explores the legends and lore—the facts and the fiction—behind the most popular of all of the cryptids: the gigantic shark known as Megalodon, Kraken the monster squid, an African dinosaur called Mokele-mbembe, the Loch Ness Monster, and Bigfoot. This series also takes a look at some lesser-known but equally fascinating cryptids from around the world:
• the mysterious, blood-sucking Chupacabras, or
“goat sucker,” from the Caribbean, Mexico, and South America
• the Sucuriju, a giant anaconda snake from South America
• Megalania, the gigantic monitor lizard from Australia
• the Ropen and Kongamato, prehistoric flying reptiles from Africa and the island of New Guinea
• the thylacine, or Tasmanian wolf, from the island of Tasmania
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MEGALODON: Fact or Fiction?
• the Ri, a mermaidlike creature from the waters of New Guinea
• the thunderbird, a giant vulture from western North America
Some cryptids, such as dinosaurs like Mokele-mbembe, are animals already known to science. These animals are thought to have become extinct. Some people, however, believe that these animals are still alive in lands that are difficult for most humans to reach. Other cryptids, such as the giant anaconda snake, are simply unusually large (or, in some cases, unusually small) versions of modern animals. And yet other cryptids, such as the Chupacabras, appear to be animals right out of a science fiction movie, totally unlike anything known to modern science. As cryptozoologists search for these unusual animals, they keep in mind a couple of slogans. The first is, “If it sounds too good to be true, it probably isn’t true.” The second is, “Absence of proof is not proof of absence.” The meaning of these slogans will become clear as you observe how cryptozoologists analyze and interpret the evidence they gather in their search for these awesome animals.
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1 Megalodon: The Fisherman’s Nightmare The really terrific thing, the thing that blows your mind, is imagining—and it could be true—that there are great whites way down in the deep that are 100 feet long. . . . Look, the Latin name for this fish is Carcharodon carcharias, okay? The closest ancestor we can find for it is something called Carcharodon megalodon, a fish that existed maybe 30,000 or 40,000 years ago. We have fossil teeth from Megalodon. They’re six inches long. That would put the fish at between 80 and 100 feet. And the teeth are exactly like the teeth you see in great whites today. What I’m getting at 9
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MEGALODON: Fact or Fiction?
is, suppose the two fish are really one species. What’s to say Megalodon is really extinct? Why should it be? Not lack of food. If there’s enough down there to support whales, there’s enough to support sharks that big. Just because we’ve never seen a 100-foot white doesn’t mean they couldn’t exist. . . . Can you imagine what it could do, what kind of power it would have? . . . It would be like a locomotive with a mouth full of butcher knives. —Peter Benchley, Jaws
G
reat . . . white . . . shark. . . . Odd, isn’t it? This string of three little words is scary enough to make any beachgoer think twice before wading into the water. That’s due in no small part to one other little word: Jaws. This popular novel by Peter Benchley, made into a blockbuster movie in 1975, is a gruesome tale about a great white shark that terrorizes the residents of Amity, New York, a quiet little tourist town on the Atlantic seaboard. This action-packed story of man versus man-eating monster is enough to convince anybody that the great white shark must be one of the most terrifying predators to ever swim the seven seas. The great white shark is one powerful predator. Capable of growing to a length of more than 20 feet (approximately 6 meters) and weighing more than two tons (1,800 kilograms), this huge fish sits—or rather, swims—atop the ocean food chain. Roaming cool coastal waters between the warm tropics and the frigid polar seas, this shark is constantly on the prowl for prey: fishes, pinnipeds (seals and sea lions), dolphins, and porpoises. When a great white shark attacks, it makes quick work of its victim. One marine biologist (a scientist who studies life in the ocean) once saw a great white attack a 200-pound (91 kg), 6-foot-long (1.8 m) harbor seal. It took only five
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The great white shark is one of the most fearsome predators in the sea. Great whites can reach lengths of more than 20 feet (6 m) and weigh nearly 5,000 pounds (2,260 kg). Great white sharks are known to attack humans, but such attacks are very rare. minutes for the shark to kill and eat its prey. After three huge bites, the seal was gone. Deep-sea fishermen have actually caught 20-foot (6-m) great whites on rod and reel. Think about what a trophy the jaws of such a monster make: a mouth that is a foot and a half (0.5 m) wide, lined with knife-sharp triangular teeth 2 inches (5 centimeters) long, with plenty enough room to stick your whole head inside. (Not that you’d really want to—those teeth are very sharp!) Only a highly skilled angler could safely land a fish that big, strong, and dangerous.
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MEGALODON: Fact or Fiction?
Now try to imagine what it would be like to hook a great white so big that its teeth were 6 inches (15 cm) long, dwarfing the relatively puny 2-inchers found on a 20-foot shark. What a colossal monster that would be. A white shark the size of a whale, with a mouth so big it could swallow basketball star Shaquille O’Neal in one bite. To snag such a beast would surely be a fisherman’s worst nightmare. Could such a monster really exist? Yes.
INTrODucING MEGALODON
Carcharodon megalodon is the name scientists have given this gigantic version of the great white shark. Over the years, many fossilized teeth of Carcharodon megalodon—usually just called Megalodon, which is Greek for “mighty tooth”— have been discovered and carefully dug out of sedimentary rocks. Hundreds more have been scooped up from the bottom of the ocean. The largest Megalodon tooth ever found measured a whopping 6.8 inches (17.3 cm) long. It was as big as a man’s hand. Although Megalodon teeth are much larger than teeth of the white shark, their shape is almost identical: fat triangles with saw-tooth serrations along both sides. In fact, the teeth of these two species of shark are so similar that ichthyologists (scientists who study fish) are pretty sure the sharks themselves must be similar as well. Some people have even suggested that Megalodon is nothing more than a supersized great white shark. Until someone catches one of these leviathans, we won’t know for sure. It should be noted that many scientists believe that Megalodon and the white shark are closely related species belonging to the same genus, Carcharodon. However, some shark experts disagree and think that the teeth of these two fishes are different enough—Megalodon teeth have relatively smaller serrations along the edges and possess
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This fossilized Megalodon tooth is estimated to be 5 million years old. Numerous megalodon teeth have been found worldwide, which suggests that the shark was once very widespread in the world’s oceans.
a scarlike mark near the base—that Megalodon ought to be placed in a different genus, Carcharocles. This theory is strengthened by the recent discovery of a rare, complete fossil jaw of an ancestor of the great white shark. The size and arrangement of the teeth in this 5-million-year-old fossil indicate that the great white may be more closely related to another man-eater, the mako shark (genus Isurus), than it is to Megalodon. Be that as it may, scientists generally agree that Megalodon and the great white are very similar and probably look a lot alike.
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MEGALODON: Fact or Fiction?
What’s In a Name?
S
cientists who classify organisms are called taxonomists. Taxonomists place each kind of organism within a seven-level system of classification. The smallest unit in this system is the species. A species is what we normally recognize as a particular type of organism: a muskrat, a bald eagle, a great white shark, or a Megalodon. Closely related species are grouped together in the next level of classification, the genus. Closely related genera (the plural of genus) are grouped together into a family; similar families are grouped together into an order; similar orders into a class; similar classes into a phylum; and finally, similar phyla (the plural of phylum) into a kingdom. The complete classification of Megalodon is as follows: Kingdom: Animalia Phylum: Chordata Class: Chondrichthyes Order: Lamniformes Family: Lamnidae Genus: Carcharodon Species: megalodon
Unfortunately, most shark experts doubt that anyone ever will catch a live Megalodon. They think the huge shark is probably extinct; after all, no one has ever laid hands on one, living or dead. Nevertheless, scientists have been able to draw a pretty detailed picture of what Megalodon probably looked like and how it probably lived. They’ve been able to do this by studying fossils of extinct sharks and by analyzing the appearance and behavior of modern-day
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When referring to a particular organism, scientists normally just use its genus and species names. These names are written in italics, and the only letter that is capitalized is the first letter of the genus name. Megalodon’s formal name is therefore Carcharodon megalodon. The fact that Megalodon and the great white shark (Carcharodon carcharias) have been placed in the same genus shows that scientists believe the two sharks are closely related. (Scientific names are obtained from Latin and Greek words.) No two species are allowed to have the same scientific name. As a result, this system of classification not only shows how closely related two species are, it also guarantees that one person knows exactly which species another person is talking about. This is a definite advantage over the use of nicknames. For example, although great white shark, white pointer, white shark, white death, great white, and man-eater are all nicknames for the same fish, not everyone is familiar with them all, and some people use the term “man-eater” to refer to any species of shark known to kill and eat people (such as the mako). If someone refers to Carcharodon carcharias, however, the identity of the critter is crystal clear.
sharks, especially Megalodon’s little cousin, the great white. The picture that scientists have painted is impressive, to say the least.
reconstructing Mighty Tooth Most people wouldn’t think a person trying to reconstruct Megalodon could get very much information just by studying its teeth, yet that’s exactly what scientists have done. By
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MEGALODON: Fact or Fiction?
A Megalodon shark (Carcharodon megalodon) is pictured above the much smaller great white shark (Carcharodon carcharias). The enormous Megalodon is believed to have lived between 20 million and 1.2 million years ago.
comparing fossilized megalodon teeth with the teeth and jaws of great whites and other living and extinct sharks, scientists have a pretty good idea of what the jaws of a shark sporting such deadly dentures would look like. They know what shape the teeth would have, how big they would be, and how thick and sturdy they would be. Because Megalodon teeth are bigger and sturdier than those of a white shark, scientists believe that Megalodon’s jaws would have to be bigger and sturdier than a white shark’s in order to hold and support all those massive teeth. This
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would indicate that the rest of the skull—and therefore the whole head—would also be more massive. This evidence, in turn, would mean that Megalodon’s pectoral fins would also be larger and sturdier, to help support and steer the shark’s “top-heavy” front end as it moved through the water. The overall effect, as shark expert R. Aldan Martin explains on his Biology of Sharks and Rays Web site, would be “sort of a great white on steroids.” Just how big did Megalodon grow? Back in the early 1900s, a model of the jaws of a Megalodon was put on exhibit at the American Museum of Natural History in New York City. The Megalodon fossil teeth used in this model were obtained from several different places (and, therefore, from several
This model approximates the size of the megalodon jaw. Clearly, Megalodon was one of the most ferocious predators to ever roam the sea.
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different sharks). Using the number of teeth present in the jaws of a great white shark (about 24 in each jaw, excluding the hundreds of reserve teeth waiting to replace those that
Let’s Get Technical: External Anatomy of Sharks
D
uring the course of this investigation, it will be necessary to compare Megalodon with other shark species. In order to do this effectively, it is necessary to be familiar with some of the visible body parts of sharks. With that in mind, let’s take a whirlwind tour of the external anatomy of the shark that probably looks the most like Megalodon: Carcharodon carcharias, the great white shark. At the business end of the white shark is the tapered, pointed snout, the equivalent of a nose. Like most noses, the white shark’s nose has a pair of nostrils, located on the ventral (bottom) surface
The anatomy of the great white shark is perfectly designed for strength and speed. The anatomy of Megalodon was likely very much like that of the great white.
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break off), museum artists ended up creating a set of jaws 10 feet (3 m) wide. A Megalodon with this monstrous mouth would have been close to 100 feet (30 m) long!
of the snout, a short distance in back of the snout tip. The eyes are located a little further back, on the sides of the head. The mouth, with its tooth-studded jaws, is located directly beneath the eyes, on the ventral surface of the head. Along each side of the shark’s neck are five parallel gill slits, where water that has passed through the mouth and gills (which take up oxygen) exits the body. (Many sharks also have spiracles—small openings behind the eyes—that allow water to flow through the gills. Fast swimmers such as the great white often do not have spiracles. They supply their gills with enough oxygenated water just by swimming with their mouth open.) The shark’s equivalent of arms is its pair of pectoral fins, which are used for steering. They are located on the sides, behind and below the gill slits. The white shark’s trademark is its large, triangular first dorsal fin, located on the dorsal (upper) surface. There is an inconspicuous second dorsal fin located farther back, near the base of the tail. A small anal fin is located on the ventral surface, also near the base of the tail. The dorsal and anal fins help stabilize the shark as it moves through the water. The crescent-shaped caudal fin at the rear helps propel the shark through the water. Finally, small, paired pelvic fins are located ventrally, far back on the belly, on either side of the opening for the cloaca, a chamber that collects products of the digestive and reproductive systems before they exit the body. It’s easy to tell the sex of any shark: Each of a male’s pelvic fins has a long, fingerlike projection called a clasper that is used to introduce sperm into the female’s cloaca during breeding. Scientists believe the claspers of a full-grown male megalodon would have been 5 feet (1.5 m) long.
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Several years later, however, scientists realized that these model jaws were too big. A close look at the jaws of a great white reveals that the teeth are not all the same size: The teeth at the front of the jaws are bigger than the ones along the sides and at the back. The fossil Megalodon teeth used in the original museum model were all big front teeth. (Remember, the teeth were obtained from several sharks, not just one.) When scientists took tooth size differences into account, they calculated that the jaws of the Megalodon model should have been only about 6 feet (1.8 m) wide, meaning that the shark was only 45 to 50 feet (13–15 m) long. Since then, more fossil teeth have been discovered, including a cluster of teeth from a single shark. As a result, scientists are now able to make more accurate size predictions for megalodon. In fact, one group of researchers, led by fossil-hunting paleontologist Michael Gottfried, has come up with a mathematical formula to determine how big the owner of a given fossil tooth must have been (this formula works for the big front teeth only.) The formula is: length of megalodon, in meters = (0.96 x [front-tooth height, in centimeters]) – 0.22 The biggest Megalodon tooth discovered so far is nearly 7 inches (18 cm) long. This means the length of the owner of that tooth would have been: length = (0.96 x 18) – 0.22 = 17.28 – 0.22 = 17.06 meters This calculated length of about 17 meters, or 56 feet, seems reasonable; it’s in the general neighborhood of the estimate the museum scientists came up with for their scaled-down version of Megalodon. What would a shark of this size weigh? Whale sharks (Rhincodon typus), the largest of all living sharks, grow
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40–50 feet (12–15 m) long and weigh about 20 tons (18,000 kg), so ichthyologists feel that’s probably a good approximation of the weight of a megalodon of the same length. This was one big fish—at least twice as long and nearly 10 times as heavy as a really big white shark. A shark that big must have had an appetite to match. What would such a colossal beast eat? Fillet of whale.
A Whale of a Meal
How can ichthyologists determine what a shark eats just by looking at its teeth? It’s really pretty easy, because different kinds of teeth are designed to do different things. Take the shortfin mako shark (Isurus oxyrinchus), for example. This speedy shark feeds on squid and fish, which are slippery and hard to hold on to. A mako’s teeth are skinny and pointed, perfect for poking into and latching on to such slick prey. Another shark, the hornshark (Heterodontus francisci), actually has two very different types of teeth to handle a variety of types of prey. This little shark, which spends most of its time resting on the seabed, has front teeth that are small and pointed, perfect for grabbing and holding on to slippery bottom-dwelling fish, and back teeth that are stubby and sturdy, perfect for smashing the shells of sea urchins, crabs, and other crunchy prey. The great white shark’s strong, sharp, serrated teeth are a gruesome giveaway as far as its food choice is concerned. Unlike most other sharks, which often prey on animals small enough to be gulped down in one bite, white sharks—especially adults—prefer to prey on marine mammals, which are usually much too large to be swallowed in one gulp. (Elephant seals, one of the great white’s favorite foods, can grow very large; an adult male can reach a weight of 5,000 pounds [2,300 kg]!) A white shark likes to remove big chunks of flesh from its large prey. Its teeth serve as both fork and knife. The
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The teeth of the great white shark were designed to catch and shred large prey. Pictured here are the teeth of a very intimidating 20-foot (6-m) great white.
pointed tips stab into a seal’s body, just like the tines of a fork stabbing a piece of steak, while the serrated edges of the teeth cut through flesh and bone, like a heavy-duty steak knife. Because Megalodon’s teeth are so similar to the great white’s, scientists are pretty sure it also dined on marine mammals. While the puny white shark prefers pinnipeds, however, Megalodon probably hunted much larger prey, since most seals would be little more than an appetizer for that “locomotive with a mouth full of butcher knives.” Whales would be the most likely main course on the menu. In fact, some fossil whale bones with suspicious-looking scrape marks on them
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have been dug up along with fossil Megalodon teeth, perhaps evidence of a deadly battle between two colossal beasts.
MODErN-DAy MEGALODON: FAcT Or FIcTION?
Since the year 1918, a handful of people have reported encounters with Megalodon-sized monster sharks cruising the ocean. Can these eyewitness accounts be believed? Did these people actually see Megalodon, or did they see some other huge fish and mistakenly identify it as megalodon? Perhaps they saw nothing at all, and just made up a bunch of whopping fish tales about “the big one that got away.” Since none of these eyewitnesses provided any direct, rock-solid evidence to back up their claims, all we have to go on is their stories. Therefore, in order to evaluate and draw conclusions about these possible sightings, it is necessary to investigate whatever details these accounts provide. It’s a lot like the way crime scene investigators gather and evaluate bits and pieces of evidence obtained at the scene of some dastardly deed. It’s time to perform a creature scene investigation!
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2 One Whale of a Fish Story T
here are five recorded eyewitness accounts of possible Megalodon sightings. During the course of this text, all five stories will be investigated in detail. This section begins the investigation by analyzing two of these stories, both of which present surprisingly similar descriptions of huge sharks encountered off the coast of Australia. The first one is a truly amazing story; in fact, it just may be the biggest fish story of all time.
cAsE #1: ThE LObsTErMEN’s TALE
This account was published in 1963 in the book Sharks and Rays of Australian Seas, written by David G. Stead, an Australian naturalist. In this case, Stead presents the story told by some Australian lobster fishermen (referred to in the 24
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story as “crayfish men”) who had an encounter with a huge fish while tending to their lobster traps (“crayfish pots”). The story goes as follows: In the year 1918, I recorded the sensation that had been caused among the “outside” crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing grounds—which lie in deep water—when an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, “pots, mooring lines and all.” The crayfish pots, it should be mentioned, were about 3 feet 6 inches [1 m] in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as an indication of the state of mind which this unusual giant had thrown them into. And bear in mind that these were men who were used to the sea and all sorts of weather, and all sorts of sharks as well. One of the crew said the shark was “three hundred feet long at least”! Others said it was as long as the wharf on which we stood—about 115 feet [35 m]! They affirmed that the water “boiled” over a large space when the fish swam past. They were all familiar with whales, which they had often seen passing at sea, but this was a vast shark. They had seen its terrible head which was “at least as long as the roof on the wharf shed at Nelson’s
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Bay.” Impossible, of course! But these were prosaic and rather stolid men, not given to “fish stories” nor even to talking about their catches. Further, they knew that the person they were talking to (myself) had heard all the fish stories years before! One of the things that impressed me was that they all agreed as to the ghostly whitish color of the vast fish. Notice that Stead describes these lobstermen as being “prosaic and rather stolid”; that is, they were cool, calm, and collected people not likely to be easily upset or scared by unusual or dangerous situations. Yet, whatever these men saw while tending their lobster traps apparently upset and scared them to the point that they refused to return to their fishing spot for several days. Stead believes the remarkable length of the shark reported by the lobstermen may be an unintentional exaggeration, resulting from these normally unflappable men being so caught up in the spine-tingling excitement of the moment. He is convinced, however, that these lobstermen saw an immense shark unlike any they had seen before. This is certainly one whale of a tale. The fact that great whites are known to attack lobster traps and buoys adds a measure of credibility to the story. What makes it all the more interesting is that a surprisingly (and perhaps suspiciously) similar story was reported many years later.
cAsE #2: ThE crEWMEN’s TALE
The following account is described by author B.C. Cartmell in his 1978 book Let’s Go Fossil Shark Tooth Hunting: In the 1960s along the outer edge of Australia’s Great Barrier Reef, an 85 foot [26 m] ship experienced engine trouble which forced it to weigh anchor for repairs. Although the men subsequently refused to openly report what they had seen for fear of public
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ridicule, the captain and his crew later told friends of sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long if not longer than their boat! Experienced men of the sea, they too were certain the creature was not a whale. The fantastic size and white color of this mysterious beast sound just like a slightly smaller version of the monster reported in the lobstermen’s tale. Perhaps the lobstermen’s description of their monster shark was accurate after all. Then again, it is necessary to consider the possibility that the crewmen in Case #2 were just fabricating a copycat story. In either case, to evaluate both accounts it will help to determine the likelihood of Megalodon having the size and color described in these two stories.
My, What big Teeth you have!
If Little Red Riding Hood was impressed with the size of the Big Bad Wolf’s teeth, she would have been flabbergasted by the size of the teeth possessed by a Megalodon as big as the sharks described in Cases #1 and #2. Gottfried’s shark-length formula can be transformed into a tooth-length formula by means of a little mathematical manipulation: front-tooth height (centimeters) = (length of Megalodon [meters] + 0.22) ÷ 0.96 This new version of the formula can be used to calculate the size of the front tooth of a Megalodon of any length. Plugging the lengths of the sharks described in Cases #1 and #2 into this formula produces some pretty amazing results. Case #2 describes a shark at least 85 feet long. Since the formula uses meters to measure shark length, the metric equivalent of 85 feet (26 m) must be plugged into the
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formula. Entering this value into the tooth height formula produces: front-tooth height = (26 + 0.22) ÷ 0.96 = 26.22 ÷ 0.96 = 27.31 centimeters (10.75 inches) Thus, a front tooth from a shark as long as the one described in Case #2 would have been almost 11 inches (28 cm) long. That would make one heck of a paper weight. What about the shark in Case #1? It was even bigger— a lot bigger. How large would a front tooth from this
A great white shark tooth (left) is pictured beside a Megalodon tooth (right). Although the teeth vary greatly in size, they are similar in shape and design.
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monster be? The shorter shark length estimate was 115 feet (35 m). Plugging that into the tooth height equation gives: front-tooth height = (35 + 0.22) ÷ 0.96 = 35.22 ÷ 0.96 = 36.69 centimeters (14.44 in.) A tooth 14 inches (36 cm) long would be the diameter of a pizza! But that’s nothing. Just look at the results for the larger estimate, 300 feet (91 m): front-tooth height = (91 + 0.22) ÷ 0.96 = 91.22 ÷ 0.96 = 95.02 centimeters (37.41 in.) Just imagine: a 300-foot (91-m) Megalodon would have front teeth that were more than three feet long. You’d need a wheelbarrow to haul one of those around! The fact that the largest Megalodon tooth ever found is less than 7 inches (18 cm) long makes it hard to believe that any of the shark lengths reported in the lobstermen’s and crewmen’s tales are realistic. If Megalodon had ever grown to such humongous sizes, it is likely that fossil hunters would have occasionally found teeth much larger than the numerous hand-sized ones that have been discovered so far. The fact that this is not the case casts a shadow of doubt over both of these stories.
It’s as clear as black and White
Enough about tooth size. What about the other important detail in these two cases, the sharks’ eerie white color? Perhaps a look at Mighty Tooth’s little cousin will shed some light on this question. Believe it or not, a good way to predict a shark’s color is to consider its feeding habits. The white shark is a perfect example. Its favorite food is pinnipeds, which the shark stalks in the shallows as these animals leave or return to
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the safety of their rookeries (the beaches and rocky shores where they hang out when they’re not at sea looking for food). Because pinnipeds are excellent swimmers and have good eyesight, a white shark must be able to sneak up on its prey if it is to have any chance of catching lunch. The great white’s feeding strategy is to cruise back and forth near the bottom of the shallows, looking for a target. When it spots
Let’s Get Technical: Gottfried’s Formula
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hark expert Michael Gottfried’s Megalodon tooth formula is a handy tool. By measuring the height of any fossilized front tooth of a Megalodon, we can determine the body length of its owner. The formula is stated as follows: length of Megalodon, in meters = (0.96 x [front-tooth height, in centimeters]) – 0.22 For example, to determine the length of a shark whose front tooth is 15 cm long, plug the tooth length into the formula: length of Megalodon = (0.96 x 15) – 0.22 = 14.4 – 0.22 = 14.2 m (or 46.5 feet) This formula can also be rearranged to determine how large a front tooth would be on a Megalodon of a specific length. To do this, we simply rewrite the formula. Start with the original formula: length = (0.96 x [front-tooth height]) – 0.22 Add 0.22 to both sides of the equation: length + 0.22 = (0.96 x [front-tooth height]) – 0.22 + 0.22
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a seal or sea lion in the water, it sneaks up below or behind its prey and then lurches forward in a quick burst of power, catching its victim off guard and dealing a huge bite, causing the animal to quickly bleed to death. The shark’s dorsal surface is colored dark gray, almost black, providing camouflage as the hunting fish blends in with the dark-colored sea bottom.
Since –0.22 + 0.22 = 0, the right side of the equation can be simplified, giving: length + 0.22 = (0.96 x [front-tooth height]) Now, divide both sides of the equation by 0.96: (length + 0.22) ÷ 0.96 = (0.96 x [front-tooth height]) ÷ 0.96 Since 0.96 ÷ 0.96 = 1, the right side of the equation can be simplified, giving: (length + 0.22) ÷ 0.96 = front-tooth height Finally, flip-flop both sides of the equation: front-tooth height = (length + 0.22) ÷ 0.96 Suppose you wanted to figure how large a front tooth should be on that 14.2-meter-long shark. Using this rearranged version of Gottfried’s formula, we get: front-tooth height, in centimeters = (length of megalodon, in meters + 0.22) ÷ 0.96 = (14.2 + 0.22) ÷ 0.96 = 15 cm By using this second form of Gottfried’s formula, it’s easy to predict the size of the front teeth of sharks such as the ones described in the lobstermen’s and crewmen’s tales.
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The great white shark is white on the bottom and dark on top for good reason. The coloration makes it hard for the shark to be seen when it is hunting underwater. Seen from above, the dark top of the shark blends in with the dark ocean bottom. When seen from below, the white belly of the shark blends in with the light sky.
On the flip side, the great white’s ventral surface is very light, almost pure white in color. When seen from below, the shark’s belly blends in with the bright sky, again providing camouflage. This dark top/light bottom type of color pattern is known as countershading and is very common in fishes. Although scientists cannot be absolutely certain about Megalodon’s colors without an actual specimen, they’re pretty confident that Mighty Tooth, like its smaller, sealeating relative, had a dark top and a light belly, enabling it to sneak up on its prey.
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In that case, why would the eyewitnesses in Cases #1 and #2 declare that the monster fish was all white? Perhaps they were mistaken: Light reflecting on the water’s surface may have played tricks on their eyes. Then again, maybe this is further evidence that both stories are just fibs. Perhaps these fellows were inspired by a certain classic novel written by Herman Melville in 1851. Melville’s legendary sperm whale, Moby Dick, was—you guessed it—all white; if these two eyewitness accounts are really just hoaxes, they certainly give substance to the term “white lie”!
sIzING uP ThE EvIDENcE
What motive, other than simply pulling David Stead’s leg, would the lobstermen in Case #1 have had for fabricating such a fantastic story? It could have been an alibi to cover up the accidental loss of their lobster traps. Maybe their marker buoy drifted away because it was not securely tied to the mooring line attached to the submerged traps. Without that buoy at the surface to mark the position of the traps in the deep water below, the lobstermen would have no way to locate their traps the next time they swung by in their boat to harvest their catch. Perhaps, rather than honestly reporting such a potentially embarrassing and costly mishap to the businessman who owned the boat and lobster traps, the lobstermen tried to hide their goof-up by concocting a story about an encounter with a monster shark that had a sweet tooth for shellfish. Case #2 is also suspect. Writing in the Cryptozoology Review, shark scientist Ben Roesch states that Case #2 “drips with tabloid style and reads much like a rewritten account of the 1918 giant shark.” Furthermore, he points out that the story is “useless as evidence” for the existence of Megalodon, because Cartmell provides no references for anyone to double-check and verify his story. In common language, this
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The oceans of Australia are prime hunting territory for many species of sharks living today. The Great Barrier Reef on the northeastern coast is an especially popular hunting ground for sharks. would be a case of hearsay evidence, of no more value than gossip or rumors. It’s also interesting to note that even though Case #1 occurred in 1918, the story wasn’t published until 1963. Coincidentally, Case #2 just happened to occur sometime “in the 1960s.” It’s hard not to be suspicious about the timing of these events, especially since they both reportedly took place in the Pacific Ocean off the coast of Australia
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(the Great Barrier Reef extends all along the northeast coast of the continent, and Port Stephens is along the east coast, a bit north of the capital city of Sydney). For more than 40 years following the 1918 incident, no one reported seeing any other huge, white monster sharks. Then, at about the time the lobstermen’s tale was published in Stead’s book, the huge, white monster shark reappeared for a curtain call. Surely Stead’s sensational story would have caught the attention of Australia’s fishermen and lobstermen. The timing of these events definitely suggests the possibility that the crewmen in Case #2 simply read or heard about Stead’s story and decided to spin a tall tale of their own. On the other hand, the “fact” that two white monster sharks were sighted in the same general area might suggest that a group of gigantic white Megalodons lived off the east coast of Australia. If that were the case, however, one would expect a gigantic tooth to be hauled up from that region of the ocean floor from time to time. But as pointed out earlier, no such teeth have ever surfaced.
PrOGrEss rEPOrT #1: MEGALODON
Considering the incredible sizes and unlikely coloration of the sharks described, the questionable circumstantial evidence surrounding the timing of the publication of Case #1 and the occurrence of Case #2, and the total lack of any evidence solid enough to sink one’s—or Megalodon’s—teeth into, it’s pretty clear that neither Case #1 nor Case #2 makes a strong argument for the modern-day existence of Mighty Tooth. What about the other eyewitness accounts? Perhaps the stories of a famous author and his teenage son make a stronger case for the existence of Megalodon. It’s time to pull anchor, leave Australian waters, and set sail for the balmy open waters of the South Pacific.
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3 Like Father, Like Son T
he next two eyewitness accounts of monstrous sharks have nothing in common with Cases #1 and #2, other than that they also occurred in the Pacific Ocean. While the sharks described in Cases #3 and #4 are similar to each other, they look nothing like the ghostly white giants described in the first two accounts. Cases #3 and #4 suggest a totally different beast. This merits taking a closer look.
cAsE #3: ThE AuThOr’s TALE
Zane Grey was the author of dozens of novels about cowboys and the Wild West. He was also an avid deep-sea angler who loved fishing for big-game fishes (marlins, swordfish, and the like). Case #3 presents a brief account of Grey’s encounter with what some people think might have been a live Megalodon. 36
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While deep-sea fishing in the South Pacific in the 1920s, Grey saw a huge shark swimming near his boat. As he describes it, the shark was “yellow and green . . . [with a] square head, immense pectoral fins and a few white spots. . . . [It was] considerably longer than my boat—conservatively between 35 and 40 feet [10.5 and 12 m]. . . . I figured out that the fish . . . was not a harmless whale shark but one of the man-eating monsters of the South Pacific. Then I was more frightened than I remember for a long time.” In this account, Grey describes one massive shark, and he implies that he is well-enough acquainted with the whale shark, the largest known living shark, to know that the monster he saw was not one of these peaceful giants. Nevertheless, we must leave no seashell unturned. In order to draw a valid conclusion about Case #3, it is important to rule out the whale shark as a possible candidate for Grey’s “man-eating monster.”
One Whale of a shark
As mentioned previously, the whale shark can grow to 50 feet (15 m) long, which is longer than the shark described by Grey. Thus, the size of Grey’s shark does not exclude the whale shark as a suspect. Neither does the shape of the monster shark’s head. Unlike speedy predatory sharks such as the great white and mako, which have streamlined, pointed snouts, the whale shark has a distinctive huge, blunt snout (kind of like a square with rounded corners), with a wide mouth at the front. The whale shark is a slow-poke filter feeder. It feeds by gaping its broad jaws wide open as it slowly swims at the surface. This allows water to enter the mouth and pass out through the gills, which are equipped with filterlike structures that trap small organisms drifting in the water. Grey describes the shark he saw as having a square head.
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A whale shark is a slow swimming shark that feeds on algae and plankton. It is the largest of all the known sharks. This 20-foot (6-m) whale shark is feeding in the open water near Donsol, Philippines.
Grey mentions that his shark had huge pectoral fins. Whale sharks have relatively large pectorals, which help this large-headed shark steer and maintain its balance as it swims. (It’s probably no coincidence that scientists’ reconstruction of the massive-headed Megalodon also has relatively large pectorals.) What about the shark’s color? Grey’s shark was green and yellow, with some white spots. As it turns out, whale sharks have variable color patterns. They have a basic countershaded color pattern, with a light-colored belly and a dark background color (gray, gray-green, brown, or rusty brown) on the dorsal surface. There are usually many white
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Like Father, Like son
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or yellow spots and vertical stripes on the shark’s back, creating sort of a checkerboard pattern against the dark background color. The number and pattern of spots varies, however, from animal to animal: Some whale sharks have lots of spots, others have fewer. The coloration of the shark Grey describes is not unlike what is known to occur in whale sharks. All of this is curious, indeed. It looks like Grey was mistaken. Despite his claim to the contrary, the huge shark he describes sounds very much like a whale shark. It has the right body size, the right head shape, the right pectoral fin size, and the right coloration. If all this evidence isn’t enough to implicate the whale shark as the fish that frightened Grey, Case #4, which also involves the famous author, should remove all doubt.
cAsE #4: ThE TEENAGEr’s TALE
Case #4 took place in 1933. Grey and his son Loren were returning to the United States after a deep-sea fishing trip to the South Pacific island of Tahiti. They were passengers aboard the steamer ship S.S. Maunganui. Loren, who was a teenager at the time, witnessed the following scene as he gazed at a blotch of yellowish water visible from the steamer’s deck: At first I thought it was a whale, but when the great brown tail rose in the ship’s wake as the fish moved ponderously away from the liner, I knew immediately that it was a monstrous shark. The huge round head appeared to be at least 10 to 12 feet [3 to 3.7 m] across if not more. . . . It was my belief that this huge, yellowish, barnacled creature must have been at least 40 or 50 feet [12 or 15 m] long. He was not a whale shark: The whale shark has a distinctive white
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purplish green appearance with large brown spots and much narrower head. So what was he—perhaps a true prehistoric monster of the deep? Here again, we have a description of a huge shark the size of either a Megalodon or a whale shark. Loren Grey claims to know what a whale shark looks like and says that the big shark he saw was something else. Just like his father, however, Loren appears mistaken about the characteristics of whale sharks: The “white purplish green appearance,” brown spots, and narrow head that he claims characterize a whale shark do not characterize a whale shark at all. One seemingly irrelevant bit of information relating to Loren Grey’s story actually presents very strong evidence that his “prehistoric monster of the deep” was indeed a whale shark. According to shark expert Ben Roesch, the yellow patch of water seen near the shark was quite possibly a “cloud” of yellowish plankton (tiny organisms adrift in the water) floating at the water’s surface. Such plankton clouds are known to attract hungry, filter-feeding whale sharks. Furthermore, the curious yellow color of Loren’s shark, as well as the “yellow and green” hue of his father’s shark in Case #3, might be explained by yellowish plankton in the water. The effect would be like gazing at the shark through a sheet of yellow cellophane. Are there any other living sharks that might be mistaken for the giant sharks observed by the Greys? There is only one other shark that grows anywhere near as large as the whale shark: the basking shark (Cetorhinus maximus), which can reach a length of up to 33 feet (10 m). This is another bigheaded filter-feeder that slowly swims about at the ocean’s surface, mouth wide open, straining tiny organisms from water that passes through its huge gills. This large, brown shark has a narrower head than the whale shark, immense gill slits that extend all the way down the sides of the head,
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The basking shark, like the whale shark, is a filter feeder. It is the second largest shark in the world behind the whale shark. The basking shark is a gentle creature that poses little threat to humans.
and a distinctive cone-shaped snout. It’s not likely to be confused with anything else.
PrOGrEss rEPOrT #2: MEGALODON
Careful analysis of the descriptions of the giant sharks in Cases #3 and #4, along with analysis of the circumstances surrounding these sightings, makes it pretty clear that both cases are instances of mistaken identity. The sharks seen by Zane and Loren Grey were almost certainly whale sharks, not Megalodon.
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Let’s Get Technical: Filter-Feeding Giants
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he largest of all sharks—whale sharks and basking sharks— feed on plankton, a mix of microscopic plants and animals, small fish, shrimplike crustaceans and other tiny invertebrates. How can such big animals survive by eating such tiny morsels of food? By eating a load of them: One basking shark caught by scientists had 300 pounds (136 kg) of plankton in its stomach! Most of the food energy in the ocean is stored in the countless billions of organisms that make up this plankton soup. In order to feed their tremendous bulk, whale sharks and basking sharks must strain thousands of gallons of seawater through built-in filters located in their gills. A feeding whale shark frequently closes its huge mouth and forces seawater back through a soft, spongelike filtering material that collects plankton as the water flows through and out the gills. This spongy filter is supported by sturdy rods made of cartilage (the same substance that forms the stiff part of your nose) so that it won’t collapse and let the plankton escape. The basking shark doesn’t even bother to close its mouth when feeding; it just slowly swims forward, mouth wide open, letting the water flow through stiff, bristly, plankton-trapping structures called gill rakers. The plankton eventually gets stuck in mucous at the back of the throat, where it is swallowed. Compared with active, tooth-studded hunters such as the great white and Megalodon, basking sharks and whale sharks lead slowpaced lives of leisure. There’s still one case to go, a bizarre one to say the least. Case #5 is the story of an unusual shark attack. The target of this attack, however, was nothing as tasty as a dolphin or seal. It wasn’t even edible. Believe it or not, the victim of this attack was a boat!
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4 Things that Go Bump in the Night I
n the first four cases that were investigated, the gigantic sharks apparently did not pay much attention to the eyewitnesses’ boats as they cruised by them. That is definitely not the case in the final eyewitness account, which describes a close encounter of the toothy kind between a boat and a huge fish—possibly a Megalodon.
cAsE #5: ThE cAPTAIN’s TALE The following story of a shark attack on the cutter Rachel Cohen (a cutter is a speedy patrol boat used by the coast guard), summarized here by scientist Ben Roesch, provides 43
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an interesting glimpse into the fascinating world of shark behavior: While in an Adelaide [an Australian port city] dry dock in March 1954, workers found 17 teeth embedded in the ship’s wooden hull that reportedly resembled those of the white shark. Unlike the white shark, however, the teeth were said to have been 8 cm (3 in.) wide and 10 cm (4 in.) high; the largest white shark teeth on record measure about 6 cm (2.5 in.) in height. The teeth were arranged in a semi-circle (typical of a shark bite) about 2 m (6 ft) in diameter, and the “bite” was near the propeller. The propeller shaft itself was bent. The Rachel Cohen’s captain recalled a shudder the boat experienced one night during a storm near Timor, Indonesia. At the time, he thought it had been caused by a collision with a floating tree trunk, which are apparently common in the area. The events of this story clearly suggest that the Rachel Cohen was attacked by an immense shark. Could this really have happened, or is Case #5 just another fish tale? Fortunately, this account provides some really useful details about the attack and definitely merits further investigation.
boat hulls and Propeller shafts: Dinner, Anyone?
It just so happens that many boats have been attacked by sharks. In almost every case, the perpetrator of the crime was none other than the great white. By studying the details of some of these unusual incidents, we can start to understand the mind of the white shark, and perhaps the mind of Megalodon as well.
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Throughout history, sharks have been known to occasionally attack boats. The perpetrator is most often the great white. In this fictional illustration from 1908, young girls in a boat fight off a pair of hungry sharks.
There is actually a method to the apparent madness in white sharks’ attacks on boats. In their book Great White Shark, authors Richard Ellis and John E. McCosker present fisherman/writer Ernest Palmer’s description of the method of attack commonly used by boat-hunting white sharks: “[T]he first intimation of its presence is usually a violent thud upon the rudder, keel, or side of the boat and the propeller is frequently mouthed and shaken by the shark, presumably to test whether the object is edible.” Palmer actually witnessed
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such an attack on the propeller of the boat from which he was fishing: “The propeller struck the shark on the head three times but it continued to follow until we anchored and caught the shark with three nasty gashes in the head.”
Let’s Get Technical: Shark Senses
H
umans rely on five senses to learn about the world around them: sight, hearing, taste, smell, and touch. Sharks have all these senses, but they also have a few others, which they use to monitor their environment in ways people can do only with the help of high-tech instruments. Sharks have a pair of eyes that are similar to human eyes. Located on the sides of the head, a shark’s eyes allow it to see in almost every direction. They are especially good at seeing in the dim light of dawn and dusk, and even at night, when many sharks are on the prowl. This “night vision” is possible because of the presence of a special structure in the back of the eye, the tapitum lucidum, which reflects light onto light-detecting cells in the retina. It’s the same structure that makes a cat’s eyes glow at night in the beam of a flashlight. Sharks’ ears are located near the top of the skull. Even though the ears have no opening on the surface of the head, they are very good at detecting sounds such as those produced by injured animals flopping and splashing around in the water. Shark ears also have structures called semicircular canals, which help the fish maintain its balance as it moves through the water. Sharks have a keen sense of smell. The nostrils, located near the tip of the snout, permit water to pass into sensory structures called nasal capsules, where biomolecules such as proteins (for example, oxygen-carrying hemoglobin in the blood) can be detected in concentrations as low as one molecule per one billion water molecules. Sharks can detect the scent of prey miles away.
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Ellis and McCosker provide the most likely explanation for this rather strange behavior. Sharks have an amazing array of senses that they use to survey their undersea world. One of these senses, the electrosense, enables sharks to detect
A shark’s taste buds are located on the tongue, allowing it to taste food items as it bites or mouths them. Unusual items found in the stomachs of sharks (for example, bottles and tin cans) are believed to have been accidentally swallowed while being tasted. Countless nerve cells of various types are located beneath a shark’s skin, providing the fish with a very sensitive sense of touch as well the ability to detect bending and stretching of the body as the shark swims through the water. Sharks also possess a lateral line, a network of pressure-sensitive nerve cells called neuromasts, located on the head and along the sides of the shark. By sensing changes in water pressure, the lateral line can detect moving objects. (To get some idea of what this sense is like, climb into a swimming pool and use your hand to swish water toward your leg; even though your hand and leg never touch, your leg can feel the pressure wave of water created by your swishing hand.) Finally, sharks possess an electrosense that can detect faint electrical fields produced by contracting muscle cells of other animals. These electrical fields are detected by a network of tiny structures, called ampullae of Lorenzini, located in the skin of the head and lower jaw. This sense is used for close-range snooping, as when scrounging around for prey buried under the surface of the sea floor. The white shark is well-equipped to navigate through its watery world. Megalodon certainly was, too.
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extremely weak electrical fields, such as those produced by the contraction of muscle cells in living organisms. Some sharks’ electrosense is so sensitive that they can detect prey that is buried under sand on the sea floor. It just so happens that the metal surfaces of a boat’s propeller and propeller shaft also produce a weak electrical field in the water. It is believed that the white shark can detect these propeller-produced electrical fields; figuring that the propeller is alive, the shark bites it to see whether it’s tasty. However, that’s not the whole story. There is evidence that white sharks don’t attack boats only when they are hungry. They may also attack if they feel their turf—or in this case, surf—is being invaded.
ONE’s cOMPANy, TWO’s A crOWD
One of the most famous of all white shark attacks occurred in 1953, off the east coast of Canada. This incident is one of many shark attacks on boats described by shark expert Ralph S. Collier on the Web site of the Shark Research Committee: Commercial fisherman John D. Burns, with companion John MacLeod, set out daily in his dory [a small fishing boat] to harvest lobsters. Many dories dotted the sea in their quest of the prized crustacean, but only Burns’s had a white-painted hull. For nearly a week the white-hulled dory was followed by a large shark after leaving the harbor. Day after day the other fishermen watched in disbelief as the shark stalked Burns and MacLeod’s dory from behind, . . . No sooner would their dory put out to sea than a large dorsal fin would appear astern of the boat. Then, as the dory sailed alone on July 9, the shark charged, smashing an [8 inch, or] 20-cm hole through the bottom of the boat. . . . The shark did not return after its initial—and only—strike against the boat.
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Obviously, no one knows what that white shark was thinking when it attacked the dory, but there are two possible explanations. On the one hand, the shark may have attacked the boat in hopes of eating it. Then, when it discovered that the wooden hull was not particularly tasty, it swam off in search of a tastier meal. On the other hand, it may be that the shark viewed the dory not as a potential meal, but as a potential rival or competitor. The shark singled out Burns’s dory from all the other fishing boats. Perhaps this is because it was the only dory with a white hull. Recall that the lower surface of a white shark’s body is white. Therefore, it’s possible that the shark mistook the white-bottomed dory for another white shark, an unwelcome intruder. By ramming the dory, the shark may have been saying, in shark language, “Get out of here! This is my territory!” This interpretation of the shark’s behavior is not as crazy as it sounds, especially considering Collier’s account of another shark attack that occurred in 1989 along the California coast. In this encounter, a boat with a blue and white hull came upon a great white feeding on a harbor seal carcass. Upon the boat’s approach, the shark left the seal carcass, circled the boat, and rammed its hull. It then slapped the boat’s back end and propeller with its tail a number of times. By that point, the boat had drifted away from the seal. The shark returned to its meal and resumed eating. The tail-slapping behavior reported in this unusual incident provides an important clue as to the shark’s motive for attacking the boat. Research by marine biologist Peter Klimley indicates that tail slapping is a behavior exhibited by white sharks as they establish a pecking order around a tasty food source, such as the dead harbor seal in the above account. As Klimley describes it, “The behavior consisted of a shark lifting the caudal fin out of the water, pausing as if to direct it in a particular direction, and then rapidly
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lowering it while contacting the water with considerable force, often splashing a large amount of water in the direction of another white shark.” Two sharks competing for a seal carcass slap water back and forth at each other until one shark, the one that makes the biggest splash, wins the contest—and the prize. Tail slapping is a harmless way for white sharks to settle their differences without fighting and injuring each other. The great white that slapped the boat in Collier’s account most likely was staking its claim to the seal carcass. Since the boat did not splash back at all, and drifted away as if in retreat, the shark figured it had won the “contest,” returned to the seal, and resumed feeding.
ANALyzING ThE EvIDENcE
So how does all of this relate to Case #5? Based on all the above evidence about white shark attacks on boats, the captain’s tale certainly appears plausible. Great whites do attack boats. They bite boat hulls and propellers, either because they mistake them for food, or because they mistake them for rivals. (Unfortunately, this account does not provide enough information to determine the shark’s motive for attacking the cutter. The incident occurred at night during stormy weather, so it’s not surprising that no one reported seeing any whale carcasses floating around or any tail slapping going on.) But what about the other details in the account? Do they provide any really hard evidence to back up the captain’s story?
That’s One big Fish
If the captain’s report is accurate, the teeth found stuck in the cutter’s hull belonged to one big shark; we can use Gottfried’s formula to calculate just how big, assuming those 4-inch (10-cm) teeth were front teeth:
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Megalodon length in meters = (0.96 x [front-tooth height, centimeters]) – 0.22 = (0.96 x 10) – 0.22 = 9.6 – 0.22 = 9.38 meters, or approximately 31 feet The largest white shark ever caught was landed by fishermen in the Mediterranean Sea. It was 23 feet (7 m) long. The shark described in Case #5 was substantially longer than that—8 feet (2.5 m) longer! If that shark wasn’t megalodon, it must have been one heck of a huge white shark! If those teeth were side teeth, then the front teeth would have been even longer, meaning the shark itself would have been even bigger, which fits with the reported 6-foot-wide (2 m) bite mark on the hull. (Recall that we previously noted that scientists figured 6-foot-wide jaws would belong to a shark up to 50 feet [15 m] long.) If only someone had saved those teeth!
PrOGrEss rEPOrT #3: MEGALODON
The details presented in Case #5 are entirely in keeping with the known behavior of the great white shark, so the story cannot be dismissed outright as being phony. It’s puzzling, however, that no one bothered to save any of those 4-inch (10-cm) teeth that were supposedly embedded in the Rachel Cohen’s hull. A tooth that large would be an impressive, valuable find. A trophy, in fact. The lack of teeth as evidence casts a big shadow of doubt over the captain’s tale. As does the fact that the sources for Roesch’s account provide no references that would allow anyone to double-check and verify the story.
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Why would the captain make up such a story? Perhaps to cover up the real cause of damage to the boat: Maybe the Rachel Cohen ran aground, smashing the propeller shaft against a submerged boulder or coral reef. Such a mistake might lead to disciplinary action by the captain’s superiors. In any case, we must follow Roesch’s lead and dismiss Case #5, because all we really have to go on is hearsay evidence, and hearsay evidence is useless in creature scene investigations. Without any clear-cut evidence demonstrating the existence of Megalodon, we must consider the very real possibility that this magnificent beast is extinct. Therefore, the next step in our investigation will be to try to figure out what could have led to this shark’s demise. To do this will require taking a giant step back in time, back to an era when megalodon still ruled the ocean.
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5 A Long-Lost World S
harks have been around a long, long time. Some of the most ancient of all shark fossils belong to a little shark named Cladoselache, which cruised the ocean hundreds of millions of years ago. We know this because paleontologists have discovered numerous fossils of Cladoselache in 350 million- to 400 million-year-old sedimentary rocks, known as the Devonian Cleveland shales, located near the southern shores of Lake Erie. (“Devonian” is the name geologists— scientists who study rocks—have given to that portion of the geological time scale lasting from 408 million years ago to 360 million years ago.) This shark was about 3 feet (1 m) long, and although it lived long before the first dinosaurs roamed the land, it looked pretty much like a typical modern-day shark. It had 53
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Cladoselache had a long, streamlined body and large tail that helped it swim fast. The ancient shark is believed to have gone extinct approximately 350 million years ago.
a torpedo-shaped body, a mouth full of sharp teeth, and the usual assortment of fins found on modern sharks, including the tell-tale crescent-shaped caudal fin typical of modernday speedsters such as the mako and the great white. Cladoselache is considered to be the granddaddy of all sharks, including Megalodon. In the vast expanse of time following the reign of Cladoselache, sharks evolved into a multitude of species of different shapes and sizes. Yet, Cladoselache and most of its descendants shared one common feature: They were aggressive predators, able to hold their own while sharing the ancient seas with competitors such as giant carnivorous marine reptiles and, later, predatory whales. (In fact, good-sized fossil fish have been found in the stomachs
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of fossilized specimens of Cladoselache, proving that this little shark was indeed a very capable hunter.) Compared with Cladoselache, Megalodon is one of the newer kids on the block; the oldest fossil teeth of Carcharodon megalodon are only about 16 million years old. Yet, Megalodon—surely the ultimate marine predator and master of the underwater world—appears to have vanished off the face of the Earth. The youngest fossil Megalodon teeth discovered so far are about 1.6 million years old. After that, the fossil trail vanishes. What could have caused the extinction of such a powerful predator?
A WOrLD OF chANGE It is a warm sunny day off the coast of what will become North Carolina in another 15 million years. A mother right whale, Mesoteras, has just calved and nudges her young to the surface to draw in its first breath of air. Suddenly a large dorsal and caudal fin of a Carcharodon megalodon breaks the surface of the water and the young calf disappears within seconds in a swirl of red water. Swallowed whole by a 17 meter giant [Megalodon] shark, the Mesoteras calf dies in a scene reminiscent today of adult Great White Sharks feeding on seals off California and Australia. This bloody scene, described by paleontologist John Clay Bruner, portrays what was probably a common event in the ancient seas inhabited by Megalodon. Fifteen million years ago, however, Earth’s oceans were quite a bit different from the way they are today. By looking at these differences, we may find clues that provide an explanation for the extinction of Mighty Tooth.
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When Megalodon appeared on the scene during the Miocene Epoch, Earth’s climate was much warmer than it is today. Very few areas of Earth’s surface were cold enough
Let’s Get Technical: The Geological Time Scale
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he Earth has been around a long time: 4.5 billion years. To make it easier to study, understand, and communicate about events during this incredibly long history, scientists use the geological time scale (also called the geological time table). This scale divides Earth’s history into shorter, more manageable blocks of time. The geological time scale allows geologists to label portions of Earth history in much the same way that taxonomists use their classification system to label organisms. Instead of talking about kingdoms, families, and species, however, geologists talk about eras, periods, and epochs. For example, the shark Cladoselache lived during the Devonian Period, which extended from 408 million years ago to 360 million years ago. Megalodon first appeared in the Miocene Epoch, which lasted from 23.7 million years ago to 5.3 million years ago. The boundaries of the different divisions of the geological time scale represent sudden changes in the types of fossils contained in successive layers of sedimentary rock. (The actual age of these boundaries can be determined by measuring the relative amounts of radioactive elements, such as uranium, contained within the rock layers.) These sudden changes in the fossil record often signify major environmental catastrophes that caused the sudden extinction of many different forms of life. The most famous such mass extinction occurred 65 million years ago, when it is believed that an asteroid smashed into Earth and wiped out the dinosaurs. This catastrophe marks the boundary between the Mesozoic and Cenozoic Eras. Older rock layers are harder to date accurately than younger ones. Also, the fossil record in older layers is more patchy and incom-
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for water to freeze, and there was much less ice at the North and South Poles than there is now. Since almost all of Earth’s water was contained in the ocean, sea level was much higher
plete than in younger layers. Nevertheless, the geological time scale is a convenient tool to use when comparing rocks and fossils of different ages.
The geological time scale divides and subdivides the 4.5 billion years of Earth’s history into smaller and smaller units of time.
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than it is today. Much land that now lies above sea level actually formed the bottom of shallow Miocene seas covering thousands of square miles. One such sea covered a huge portion of the southeastern coast of the United States. One of the world’s best sources of megalodon teeth is sedimentary rocks from states such as North and South Carolina. These rocks formed from mud and other materials (along with shark teeth) that settled on the surface of the shallow Miocene seabed. Scientists don’t think that this is a coincidence. They believe that the large number of shark teeth found in these rocks indicates that Megalodon liked to hang out in these warm, shallow seas. Why? Recall that fossil whale bones have been found along with those fossil shark teeth. Apparently, Miocene whales also liked to hang out in these warm, shallow waters. Observations of modern whales suggest why this was the case. Many kinds of whale give birth in warm, shallow water near the shore. For example, female gray whales (Eschrichtius robustus) migrate thousands of miles from rich feeding grounds in icy arctic seas in order to give birth in warm, shallow lagoons along the Pacific coast of California. They do this because baby whales, called calves, have very little of the fatty, insulating blubber that protects adult whales from the cold water of their frigid feeding grounds. If calves were born in that icy water, they would quickly die from the cold. When calves are born in warm shallows, however, they have enough time to nurse on their mothers’ milk and grow a thick layer of blubber as they slowly migrate north to arctic feeding grounds. So if baby whales were present in these warm seas, it’s reasonable to figure that hungry Megalodons would have been present, too. By studying the predatory behavior of another whalehunter, namely humans, we can uncover another possible reason why Megalodons haunted these shallow seas. Back
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in the 1800s, whalers sometimes took cruel advantage of the migratory behavior of gray whales. When a female gave birth in shallow lagoons, the whalers would harpoon the calf from shore, pull the helpless youngster toward the beach, wait for the protective mother to follow behind, and then easily kill her as she became trapped in the shallow water. This was much safer than dealing with an angry mother whale in the open ocean, where she could maneuver easily, possibly ramming the whalers’ boat or smashing it with her tail.
There have been numerous ice ages in the history of Earth. The last ice age occurred during the Pleistocene Epoch and resulted in the formation of huge glaciers in Canada and northern parts of the United States.
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Perhaps Mighty Tooth was smart enough to realize that mother whales were less maneuverable in shallow water, making shallow-water hunting of calves a safer proposition. After all, there’s no sense risking being slammed by an enraged mother whale if it’s not necessary. The scene depicted by Bruner probably occurred countless times as giant sharks hunted down newborn whales in those shallow Miocene seas. Whale birthing grounds would have been Megalodon magnets. And that’s not all: Since females of Mighty Tooth’s close relative, the great white shark, give birth in shallow water, scientists believe that Megalodon might have done the same. (While many species of shark lay eggs, some, including the great white, bear live young. White shark newborns are 4-foot-long [1.2 m] miniature versions of their parents. Scientists figure that baby Megalodons would have been about 12 feet [3.5 m] long.) If that was the case, then shallow Miocene seas would have served as both dining room and nursery for the huge shark. No wonder so many fossil teeth have been found in the southeastern United States! Approximately 3 million years ago, toward the end of the Pliocene Epoch, Earth’s climate took a turn. Temperatures worldwide cooled off, and snow and ice began to accumulate in ever-greater amounts at the poles, especially the North Pole, where huge glaciers grew and spread south. Eventually, huge sheets of ice covered thousands of square miles of land in North America, Greenland, Europe, and Asia. The Ice Age had arrived.
The Triple Whammy
During the peak of the Ice Age, during the Pleistocene Epoch, so much water was locked up in the huge northern glaciers— towering sheets of ice up to 1.2 miles (2 km) thick—that the sea level dropped more than 330 feet (100 m), completely
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A group of four killer whales surround their prey—a gray whale mother and calf. The group would eventually kill the calf, but the mother was able to escape. draining many of the shallow Miocene seas that were hangouts for Megalodon. By now, this warm-water shark had to deal with both colder water and the loss of its favorite places for feeding and giving birth. But that’s not all. There was now a newer kid on the block, one that was tough enough to stand up to the biggest, baddest shark the world had ever known. This new tough guy hunted in packs—pods, to be precise— and was able to take down even the largest of whale prey. Just who was this new tough guy, competing with Mighty Tooth for the title of Top Predator of the Seven Seas? None other than Orcinus orca: Orca, the killer whale.
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It’s hard to believe, but the ancestors of Shamu and Namu, those lovable Sea World clowns who tow divers around the pool, splash spectators in the front row, and kiss little children with their big, fat tongues, might have beaten out Megalodon for the top spot in the marine food chain and played a part in Mighty Tooth’s extinction.
Let’s Get Technical: Fossil Shark Teeth
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harks lose a lot of teeth. It’s not uncommon for a shark to lose one or more teeth when feeding, especially when the prey has thick or tough skin. A lost tooth, however, is no big deal to a shark. Sharks have several rows of teeth, although only those in the front row are used for biting. The teeth in the other rows are replacements. If a front-row tooth gets yanked out by a struggling seal—or boat hull—the tooth behind it in the second row moves forward to replace it. Sharks have lost so many teeth over the eons that fossilized shark teeth are among the most common of all fossils. A fossil Megalodon tooth consists of several parts. The relatively soft, spongy center of the tooth is the pulp. (In live sharks, the pulp contains tiny blood vessels and nerve cells.) The pulp is surrounded by a relatively thick layer of a strong, hard substance called dentine. The dentine layer is covered by a thin layer of enamel, a material that is extremely brittle and hard—harder even than bone. The enamel is glued to the underlying dentine by a substance called cementum. The bottom of the tooth, the root, attaches to the jaw. Along the side of the tooth, where the root meets the upper part of the tooth (the serrated, triangular blade), there may be a scarlike mark called the bourrelet. (Megalodon teeth have a bourrelet; white shark teeth do not.) A tooth lost by a shark settles on the ocean floor and is eventually covered by the muddy, sandy sediment that is deposited in the ocean by rivers. Over time, more and more material accumulates on top of
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One-on-one, an adult Megalodon would have been able to hold its own against a single 25-foot-long (8 m) killer whale. It probably didn’t stand a chance, however, against a pod of several smart, speedy orcas. To say orcas are smart may be an understatement. These largest members of the dolphin family employ an amazing variety of hunting
the tooth. The increasing weight of this ever-deepening layer of mud and sand eventually compresses the material surrounding the tooth into sedimentary rock. While this compression proceeds, water and chemicals in the sediment slowly interact with the materials in the tooth. As water is slowly absorbed by the tooth, the dentine gradually swells like a sponge, cracking the thin overlying enamel layer, and then slowly dissolves. As the dentine dissolves, it is replaced by various minerals that were dissolved in the water. Meanwhile, the enamel becomes stained by substances in the surrounding sediment, taking on a color ranging from creamy peach or yellow to rusty red, brown, or even black. Only freshly shed shark teeth are white; fossil teeth are always discolored. This is why Richard Ellis and John McCosker comment in their book Great White Shark: “Should someone, then, dredge up a white Megalodon tooth, we would know that the giant shark became extinct quite recently—or is flourishing somewhere in the vastness of the oceans and has simply lost a tooth.” This entire fossilization process can take up to 100,000 years to complete. Eventually, perhaps millions of years later, sedimentary rock containing a trapped fossil shark tooth may be brought to the earth’s surface during mountain-building processes and/or earthquakes, where the rock is weathered by wind and water until the fossil is exposed and, ultimately, detected by the watchful eye of a fossil-hunting cryptozoologist.
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strategies when pursuing prey. It’s almost impossible to outsmart them. Because orcas and wolves both hunt in groups (pods and packs, respectively), orcas have earned the nickname “wolves of the sea.” When hunting schools of fish or pods of their smaller dolphin cousins, orcas surround their prey, herd them into a tight circle to cut off escape, and then go in for the kill. Pinnipeds are among the killer whale’s favorite foods. Seals and sea lions sometimes have the opportunity to employ an escape strategy unavailable to fish and dolphins: They can haul out onto land or, in frigid climates, floating chunks of sea ice called ice rafts. (In such a situation, “life raft” might be a more appropriate term.) Yet, orcas have found several ways to get around this seemingly fool-proof escape strategy. When a seal seeks refuge on an ice raft, a hunting killer whale may splash waves of water up onto the ice, washing the seal back into the water, where it is quickly caught and consumed. Sometimes, the orca actually jumps out of the water and onto the ice, knocking the seal back into the water. Or it may ram the ice raft from below, tipping it up and causing the seal to slide into the water. If an orca spots a seal on land close to shore, it may actually launch itself onto the beach and slide on its belly right up to its terrified target, grab its meal, and then make its way back into the water. When a pod of orcas attacks large prey, such as a big whale, the orcas will surround their quarry, boxing it in from all directions, and then take turns, tag-team style, biting chunks of flesh from their helpless victim. This type of assault is very effective against whales much larger than orcas. Scientists aboard a Sea World research ship once witnessed such an attack on a 60-foot-long (18.2 m) blue whale. Sharks are known to be an item on the orca’s menu, so it’s possible that orcas’ Pleistocene ancestors used this whalehunting strategy against Megalodon, always steering clear of
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the shark’s dangerous mouth. They might also have subdued the giant shark by smashing into it battering ram-style, aiming for the gills or other vulnerable areas. A newborn Megalodon, even though 12 feet (3.5 m) long, would have been a sitting duck for even a lone hungry orca. In fact, humans have witnessed what could be considered a reenactment of an attack by an orca on a young Megalodon. In 1997, Peter Pyle, a Point Reyes Bird Observatory biologist stationed at the Farallon Islands off the coast of California, was notified by the captain of a tourist boat that he had just witnessed a killer whale attacking a white shark. When Pyle arrived on the scene, he saw the smaller of two orcas dragging the carcass of a 10-13 foot (3-4 m) white shark—the exact size of a newborn Megalodon—along the surface of the water. A few minutes later, the shark’s liver squirted out of its tattered body, whereupon the orca released the carcass and gulped down the liver. What remained of the dead shark slowly sank out of sight. Pyle and his colleague Alisa Schulman-Janiger put the pieces together and determined the probable sequence of events that led to the white shark’s demise: A dead sea lion seen floating at the surface (the Farallon Islands are famous for their huge pinniped rookeries) had probably just been killed by one of the orcas. The hungry shark smelled the sea lion’s blood in the water and came over to investigate, whereupon one of the orcas, upset by the shark’s approach, attacked and killed it, probably by ramming it and then shaking it to death. What happened next was quite unexpected. The waters around the Farallon Islands are normally a popular hunting ground for great whites from September through December, when elephant seals gather at the rookeries to breed. During these months, dozens of the big sharks normally patrol the nearshore waters, looking for food. As soon as the orca killed the inquisitive shark, however, the other white sharks quickly
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vanished from the area. They apparently smelled the tattered remains of the dead shark and decided to leave their hunting grounds before they ended up as the orca’s dessert. Three years later, a similar incident occurred at the Farallones. A male white shark named Tipfin—so named by researchers studying white shark migration—presented an interesting tale. The researchers had attached an electronic “pop-up” tag on Tipfin’s back in order to record the temperature and depth of the water in which he was swimming. The pop-up tag recorded temperature and depth every two minutes for six months and then popped up to the surface (hence its name) and transmitted its recordings to the researchers via satellite. When the scientists studied Tipfin’s depth data, they were surprised to find out that at almost the exact time that witnesses had spotted a huge fish—probably a white shark—that had just been killed by a killer whale, Tipfin descended from the surface to a depth of 1,640 feet (500 m) and hightailed it away from the islands. Clearly, orcas and white sharks do not get along. They are competitors that hunt the same prey, and the whales sometimes prey on the sharks. (It’s also possible that white sharks on rare occasions attack baby orcas.) It’s likely that Megalodon and the ancestors of today’s killer whales were also fierce competitors for the same reasons. Unfortunately, when two species compete for food or other critical resources, one species often survives at the expense of the other, which eventually goes extinct. We know that the ancient orcas survived; Shamu and Namu are proof of that. We can’t say the same for Mighty Tooth. As if orcas weren’t enough of a problem for Megalodon, the fossil record shows that many of the whale species that Megalodon probably preyed upon disappeared during the Ice Age cool-down. This disappearance probably took place because the whales’ own food (fish, squid, plankton, and more) could not survive in the colder climate.
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With all these things happening at the same time, it’s hard to determine just what brought about the extinction of Megalodon. Most scientists believe that no single factor was responsible for knocking off the giant shark. Many ichthyologists believe that the effects of the Ice Age, competition from orcas, and the disappearance of Megalodon’s preferred prey combined to produce a triple whammy that was just too much for the shark to handle. In any event, by the middle of the Pleistocene, Carcharodon megalodon was gone. (As mentioned previously, the youngest Megalodon teeth found so far date back to the Pleistocene, more than one million years ago—pretty strong evidence that the shark is now extinct.) How do paleontologists know that all the Megalodon teeth that have been found are actually fossils? That’s easy. Recently shed shark teeth are always white, whereas fossil teeth are discolored, anything from a creamy color to almost pure black—stained by the chemicals in the sediment in which they were buried. No white Megalodon teeth have ever been found. Despite this fact, some people refuse to give up hoping that Megalodon still survives somewhere in the vast depths of the world’s oceans. Is this just wishful thinking, or do these people have good reason to believe that Mighty Tooth might still exist? As the next section shows, the ocean is full of surprises, some of which would equal the discovery of a living Megalodon, even a ghostly white one.
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6 Mysteries From the Deep Blue Sea I
f you have seen the 1993 movie Jurassic Park, you may remember the dropped-jaw look of utter amazement on Dr. Grant’s face when he encounters his first live dinosaur. Speechless and weak in the knees, he crumples to the ground, hardly able to believe what he is seeing. After all, the last of the dinosaurs were supposed to have been wiped out 65 million years ago, when a giant asteroid smashed into Earth. Now, everyone knows that Michael Crichton’s Jurassic Park is pure fiction, but does that mean nothing so amazing could possibly happen in the real world? Is there no chance that a species thought to be extinct for millions of years couldn’t have survived undetected, leaving no trace— 68
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Once thought to be extinct, a coelacanth was discovered in the ocean off the coast of South Africa in 1938. Since then, other living specimens have been found, but their sightings are rare, and the fish is classified as an endangered species. Coelacanths are deep-sea creatures that live at depths of up to 2,300 feet (700 m).
not even a single fossil—and then suddenly reappeared, alive and well, before the amazed eyes of the scientific world? As it turns out, something like this actually did happen a number of years ago: An animal that was thought to have gone extinct even before the dinosaurs met their end was found alive and living in—you guessed it!—the deep, dark depths of the ocean. Just what kind of animal pulled off this amazing disappearing act? A fish. Mind you, this was no teeny, tiny guppyof-a-fish that could easily be overlooked in the vast expanse
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of the ocean. This 5-foot-long (1.5 m), 127-pound (58 kg) lunker, known as a coelacanth (SEE-luh-kanth), was almost as big as the scientist who identified it. It had a big, toothy mouth, huge armorlike scales, and stubby, lobe-shaped fins. The fossil record of lobe-finned fishes petered out during the Cretaceous Period, about 80 million years ago, which is why the discovery of a living coelacanth was so astonishing. It’s worth taking a close look at this unusual fish story, because people who believe Megalodon may still exist feel that the story of the coelacanth supports their stance. If this lobe-finned fish could survive unknown and undetected into modern times, perhaps Megalodon could do the same.
ThE cOELAcANTh’s sTOry
The year was 1938, five years after Loren Grey’s encounter with his “prehistoric monster of the deep” in Case #4. Upon returning to the port town of East London, along the east coast of the nation of South Africa, Hendrick Goosen, captain of the fishing boat Nerine, relayed a message to Marjorie Courtenay-Latimer, the curator of the East London Museum. He invited her to come down to the dock to examine the fishes that his crew had just caught in their trawling net. (A trawling net is a huge fish net that is dragged along the bottom of the ocean.) He told Courtenay-Latimer she could buy any of the fishes that she wanted for the museum’s fish collection. Along with the usual assortment of sharks, cod, and other deep-water fishes was an unusual one that CourtenayLatimer had never seen before. It was a large purplish-blue fish with shiny, silvery spots and unusual, lobe-shaped fins. She bought the fish and brought it back to the museum. Unable to identify it, she sent a description of the weird fish to James L.B. Smith, a teacher at Rhodes University in Grahamstown, some 50 miles (80 km) south of East London. Smith, who taught chemistry at the university, was also a fish expert.
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After researching the information provided by CourtenayLatimer, Smith concluded that she was describing a crossopterygian, or lobe-fin. Many scientists believed this fish might have been the ancestor of amphibians, the first vertebrates (animals with backbones) to crawl out of the water and onto the land. According to the fossil record, crossopterygians first appeared during the Devonian Period, just like the ancient shark, Cladoselache. Unlike sharks, however, lobe-fins were thought to have become extinct. To discover a living lobe-fin would be the scientific find of the century! By the time a very excited Smith arrived in East London, Courtenay-Latimer’s fish had started to decompose, and the internal organs had been removed and discarded. Nevertheless, when Smith finally gazed upon the remains of the fish, he knew in an instant that he was staring at a real, honest-to-goodness crossopterygian: a coelacanth! Quoted by Samantha Weinberg in her book A Fish Caught in Time: The Search for the Coelacanth, Smith was obviously thunderstruck by what he saw. “Although I had come prepared, that first sight hit me like a white-hot blast and made me feel shaky and queer, my body tingled,” he said. “I stood as if stricken to stone. Yes, there was not a shadow of doubt, scale by scale, bone by bone, fin by fin, it was a true Coelacanth.” In a newspaper article that he later wrote about his encounter with the coelacanth, Smith included a bit of advice for his fellow scientists: “We have in the past assumed that we have mastery not only of the land but of the sea. We have not. Life goes on there just as it did from the beginning. Man’s influence is as yet but a passing shadow. This discovery means that we may find other fishlike creatures supposedly extinct still living in the sea.” Some people believe that Megalodon might be one such creature. The coelacanth isn’t the only amazing, totally surprising fish to come to ichthyologists’ attention in the past 70 years. In 1976, a remarkable creature was accidentally caught in the anchor of a U.S. Navy boat. This was no tiny guppy-of-a-fish,
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either. Appropriately enough, this fish was actually a shark— a big shark.
MEET MEGAMOuTh In 1976, crewmen aboard the AFB-14, a Navy research vessel, were in for a real surprise when they hauled in the boat’s sea anchors. (A sea anchor is like an underwater parachute that is dragged in the water behind a boat, slowing it down but not stopping it.) They discovered that one of the sea anchors, which had been drifting at a depth of 500 feet (152 m) off the shore of Hawaii, had been swallowed by a huge shark with a large, seemingly oversized head. The shark was more than 14 feet (4.3 m) long and weighed more than 1,500 pounds (680 kg). Its mouth was studded with thousands of tiny teeth and surrounded by thick, fleshy lips.
Let’s Get Technical: Coelacanths
A
coelacanth is a “living fossil.” The modern-day coelacanth (its scientific name is Latimeria chalumnae) looks almost identical to its fossilized ancestors that lived hundreds of millions of years ago, during the Devonian Period. Its crossopterygian relatives gradually evolved into the first amphibians, some of which eventually evolved into the first reptiles, some of which in turn evolved into the first mammals (the whole process taking a couple hundred million years). The coelacanth itself, however, stayed pretty much just the way it was, a creature obviously very well suited to living the life of a coelacanth. Coelacanths spend the daylight hours resting in caves hundreds of feet beneath the surface. They are nocturnal hunters, leaving the protection of their caves by night and swimming up into shallower water. There, their large eyes help them find their fish prey in the dimly lit water. Coelacanths eat a wide variety of fishes, including
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Appropriately dubbed “megamouth” because of its huge mouth, this previously unknown fish turned out to be another filter-feeding shark. In fact, scientists eventually classified it as a distant relative of the much larger filter-feeding basking shark and gave it the name Megachasma pelagios, meaning “big mouth from deep water.” Several more megamouth sharks have been caught in the years since the anchor-eater was caught in 1976. In 1984, a 15-footer (4.6 m) was caught at a depth of 125 feet (38 m) in a fisherman’s net off the coast of California, near Los Angeles. Others have since been found near Japan and Australia. Scientists believe that megamouth is a deep-water filterfeeder, which would explain why it avoided detection for so long. By spending most of its time in the depths, it would have avoided detection by people in boats at the surface. Since it eats plankton and other small critters, it wouldn’t be
eels, rays, and small sharks, which they snatch up with their large, powerful mouths. These primitive-looking animals are obviously very capable hunters. Not surprisingly, fishermen of the Comoros Islands usually catch coelacanths on their fishing lines at night, when the coelacanths are out and about searching for prey. The secretive nature of the coelacanth explains why it remained undiscovered by scientists for so long. If it hadn’t been for Marjorie Courtenay-Latimer’s lucky discovery of that first coelacanth among all the other ordinary fishes hauled in by the trawler Nerine, we might still be unaware that coelacanths have survived into modern times. This is why some people believe that Megalodon may still be around: It may be living a secretive way of life as well, out of the view of humans—although, quite frankly, it’s hard to imagine how 45-footlong (14 m), whale-eating sharks could go unnoticed for long!
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This stuffed megamouth shark was caught in August 2003 in the Pacific Ocean. This one-of-a-kind stuffed fish was on display at a Japanese museum where curious kids could get an up-close look.
tempted to latch onto large baitfish on a hook the way other open-water predatory fish (such as other sharks, marlin, and swordfish) would. Such a lifestyle is in stark contrast to that of Megalodon, the streamlined, speedy, shallow-water, whale-slaughtering machine which could hardly be expected to remain hidden from view for very long. As if in response to those who believe that Mighty Tooth still survives, author Richard Ellis points out in Great White Shark that a number of megamouths have now been observed, but so far not a single live Megalodon has been sighted. If Megalodon did
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still exist, one would expect it to be encountered at least as frequently as the secretive megamouth.
DEEP-DIvING?
Recent research by ichthyologists has revealed some surprising information about the migratory habits of Megalodon’s little cousin, the great white shark. For years, most ichthyologists had assumed that white sharks spent almost all of their time moving back and forth between feeding and breeding grounds located in shallow coastal waters, particularly around Australia, South Africa, and the east and west coasts of North America. They now know that this is not the case. In the 2000 study in which scientists made the acquaintance of Tipfin (the male white shark mentioned earlier), ichthyologist Barbara Block of the Tuna Research and Conservation Center, Peter Pyle, and several colleagues attached pop-up tags to Tipfin and five other white sharks. The scientists discovered that, as they suspected, sharks that visit the Farallon Islands during elephant seal breeding season stay near the shore and rarely dive deeper than 90 feet (27 m). What surprised the scientists was what happened after the seals dispersed at the end of breeding season: Most of the tagged sharks headed offshore into the deeper waters of the Pacific Ocean. Two of the sharks stayed near the Farallones, but three of the sharks swam to open water several hundred miles to the southwest, and Tipfin, following his close encounter with the shark-eating orca, swam 2,280 miles (3,650 km) due west, all the way to Hawaii, averaging 43 miles (68 km) per day! He then returned to the Farallones the following November, at the peak of the elephant seal breeding season. The researchers discovered that the tagged white sharks spent up to five months of the year swimming in the deep waters of the open ocean, often swimming at a depth of
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MEGALODON: Fact or Fiction?
approximately 1,000 feet (305 m). Why did those sharks travel such long distances in the open ocean? No one knows for sure. According to Burney Le Boeuf, one of the researchers involved in the study, “What they were doing out there is a mystery. Since they were hunting for seals when tagged, such a long migration suggests a possible rendezvous for mating, or a move to feed on different prey.” As impressive as Tipfin’s journey to and from Hawaii was, it pales in comparison to the record-setting voyage undertaken by Nicole, a female white shark tagged in the shallow waters near pinniped rookeries off the coast of South Africa. Nicole was one of 32 white sharks tagged in November of 2003 by scientists from the Marine and Coastal Management Department of South Africa. While the sharks commonly migrated up and down the east coast of South Africa, Nicole headed due east and swam all the way to Australia, nearly 7,000 miles (11,200 km) away! During her 99-day voyage, Nicole often swam at the incredible depth of more than 3,200 feet (976 m). Nicole’s pop-up tag detached and floated to the surface while she was in Australian waters, but scientists know that she returned to South African waters the next summer: They spotted her uniquely marked dorsal fin—identical to photos taken the year before—slicing through the waves along the South African coast in August of 2004. The results of these studies of white shark migration might encourage people to believe that Megalodon still exists. After all, if Tipfin, Nicole, and other white sharks have been found to spend a lot of time hidden from view in the deep water of the open ocean, who is to say that Megalodon doesn’t do the same? The truth of the matter is, no one can state with 100% certainty that Megalodon does not live in the abyss. We can be 99.99% certain, perhaps, but not 100%—not until we’ve thoroughly searched the world’s oceans, top to bottom, and
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come up empty. Still, Ellis’s reasoning is hard to argue with: If Megalodon were still around, we should have seen it—or at least some of its huge, white teeth—by now.
LOrD OF ThE DEEP
One other point needs to be presented before we close the book on Megalodon. Recall from the preface that the first step in any cryptozoological investigation involves gathering as much information about the cryptid as possible. Of particular value is information provided by people who live where the cryptid hangs out. The story of the coelacanth is a case in point. Even though scientists were totally convinced that coelacanths were long extinct until Courtenay-Latimer’s surprising discovery, the lobe-fin was not unknown to natives of the Comoros Islands, located off the east coast of Africa. Fishermen from the Comoros occasionally catch coelacanths on their fishing lines. They even have a name for the lobe-fin: gombessa. This example is proof positive that native people of so-called “primitive” cultures are likely to know more about the natural world that they work and live in than do highly educated scientists of modern, “advanced” cultures from other parts of the world. The coelacanth isn’t the only animal discovered by scientists long after it became known to local inhabitants. Many animals now commonly seen running, swimming, or flying in zoos, on the pages of nature magazines, and on TV documentaries were known to native cultures for countless generations prior to their discovery by scientists and explorers from Europe and elsewhere. Examples include the white-backed tapir from India, a distant relative of the rhinoceros, “discovered” in 1816; the African pygmy hippo in 1849; China’s giant panda in 1869; and the mountain gorilla, the largest of all the apes, in 1903. By noting instances such as these, it is obvious why cryptozoologists begin their cryptid quests by gathering as much
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MEGALODON: Fact or Fiction?
Many animals have been discovered by scientists of the western world in the last two hundred years. Examples include the whitebacked tapir (top) and the African pygmy hippo (bottom).
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information as possible from people who are neighbors of their quarry. What does all this have to do with Megalodon? It just so happens that native fishermen of some islands in the South Pacific believe in the existence of a 100-foot-long (30 m) sharklike creature that they call the Lord of the Deep. It’s a traditional belief that goes back many generations. As unbelievable as such a beast would appear to modern science, one can’t help but wonder if there is more than just a grain of truth behind this belief. It might also make one wonder whether some of those cases we’ve explored are not quite so far-fetched after all. The stories related by Zane and Loren Grey appear to be cases of mistaken identity. But what about the lobstermen’s, crewmen’s, and captain’s tales? Even though the evidence—or lack thereof—casts a cloud of doubt and suspicion over the truth and accuracy of these accounts, they can’t be ruled out with absolute certainty. After all, we weren’t there to witness what, if anything, actually happened. Even though it’s a long shot, maybe, just maybe, these suspicious-sounding stories are based on actual sightings of that mysterious creature known in some places as the Lord of the Deep. The point is, we shouldn’t be totally surprised if, someday, the front pages of newspapers throughout the world scream out with the headline “Cryptozoologist Captures ‘Lord of the Deep’ ”. Such a headline would be accompanied by a photo of a person smiling while standing in the sand at ocean’s edge, next to some beached marine monster—perhaps a gigantic shark, perhaps a whale, or perhaps something totally new to science. History has taught us that such things have happened before. They will probably happen again.
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7 Final Report: Megalodon A
ll the Megalodon data has been collected and analyzed, and a brief summary of our findings is now in order. The lobstermen’s tale (Case #1) describes an incredibly huge (between 115- and 300-foot-long, or 35- and 91-m-long), white shark with a taste for lobster. Studies of the great white shark, megalodon’s closest living relative, suggest that Mighty Tooth might indeed make a meal of the lobstermen’s catch, even though marine mammals, especially whales, are probably this shark’s preferred prey. So this part of the account is believable. The all-white coloration claimed for this fish, however, flies in the face of what scientists know about fish color patterns. Countershading is the rule, rather than the exception, for stealthy predators such as the great white and, presumably, for Megalodon. A monstrously huge, all-white 80
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shark would have an awfully hard time sneaking up on intelligent, sharp-eyed, whales. Finally, by using Gottfried’s formula, the front teeth of a shark the size reported in this case were calculated to be up to 3 feet (91 cm) long. Since the largest of the hundreds of Megalodon teeth that have been found to date is barely 7 inches (18 cm) long, the possibility that shark tooth collectors could have overlooked such huge teeth would seem extremely unlikely. The problem with the shark’s color and size, combined with a possible financial motive to make up such a wild story to explain the costly loss of the ship owner’s lobster traps, makes the lobstermen’s tale a poor source of evidence justifying belief in the modern-day existence of Megalodon. The crewmen’s tale (Case #2) does not fare any better under careful analysis, and for pretty much the same reasons. The white color and the incredible size claimed for the fish in this account make for a story as hard to believe as Case #1. Although there does not appear to be a monetary motive for making up this tale, the coincidence in the timing of the telling of this story and the publication of Case #1 in David Stead’s Sharks and Rays of Australian Seas suggests that the crewmen’s tale is simply a copycat hoax. The author’s and teenager’s tales (Cases #3 and #4, respectively) are both clear-cut cases of mistaken identity. Comparative studies of the teeth of Megalodon and the great white shark indicate that Megalodon looked like a supersized, beefy version of the great white. The accounts by Zane Grey and his son Loren of the huge sharks they encountered on their South Pacific fishing excursions describe sharks that look very much like whale sharks, which look very different from great whites. Furthermore, Loren’s mention of a blotch of yellow water near the shark he saw is the real clincher. That yellow smudge was almost certainly a cloud of plankton, the whale shark’s preferred food.
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Throughout history, people have been captivated by the thought of a giant shark that stalks the seas, such as the ferocious creature in the blockbuster film Jaws. In this photo, two children play with the famous lead character at Universal Studios, Florida.
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The captain’s tale (Case #5) is an interesting account, as it implies that the cutter Rachel Cohen was attacked by a huge shark with a 6-foot-wide mouth. That mouth size is appropriate for a shark the size of a large Megalodon, and the reported attack on the cutter’s propeller is entirely consistent with the known behavior of Mighty Tooth’s little cousin, the great white. No one, however, appears to have saved any of the extremely valuable 4-inch-long teeth that were reportedly found stuck in the cutter’s hull. In addition, the source for the story provided no references that could be checked for accuracy and honesty. Therefore, the whole story is unfortunately just that: a story . . . and nothing more. To sum things up, we’ve analyzed all five eyewitness accounts of possible Megalodon sightings. Three of the accounts (Cases #1, #2, and #5) are unverifiable at best and hoaxes at worst, and two (Cases #3 and #4) are obvious cases of mistaken identity, where the giant sharks sighted were almost certainly whale sharks and not “man-eating monsters.” With meager evidence such as this, it is not surprising that most scientists (including many cryptozoologists) believe that Megalodon is extinct. The evidence obtained from all five cases is strictly hearsay, and while some of it agrees with what scientists know about shark behavior (for example, attacks on lobster traps and boats), some of it conflicts with known facts about shark size and coloration. There is no way the information extracted from these five cases can override two important facts: first, no actual specimen of Megalodon, dead or alive, has ever been found; and second, all of the Megalodon teeth found to date are fossils no less than 1.5 million years old. On top of that, scientists have come up with a very convincing explanation for Megalodon’s probable demise: the triple whammy effect of the Ice age (which resulted in cooler water temperatures and the disappearance of shallow seas), the
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Let’s Get Technical: Shark Teeth for Sale
M
egalodon may have disappeared from the world’s oceans, but its fossilized teeth can be found all over the world— on the shelves of fossil dealers. Megalodon teeth are among the most popular items purchased by fossil collectors. Prices posted for these
FPO image
A Christie’s auctioneer oversees the auction of a giant Carcharodon megalodon shark jaw at Christie’s house in Paris on April 7, 2009. The jaw was part of a collection of prehistoric fossils, but the costly fossil did not sell that day.
disappearance of the shark’s favorite whale prey, and fierce competition from the ancestors of the killer whale. After taking all the above findings into consideration, we must conclude that there is no reason to believe Megalodon still exists—except in hopeful imaginations. Still, the stories of megamouth and the coelacanth show that the ocean is
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teeth depend on their size, color, and condition, and can range from $10 for a 1.5-inch (3.8-cm) weathered, chipped, and/or cracked specimen, to $7,000 for a 6-inch (15-cm) tooth in pristine condition— having nice, sharp serrations along the edges, and few if any cracks or chips in the enamel. The enamel in the most valuable specimens has beautiful color patterns that rival those seen in fine jewelry and gemstones. In fact, some dealers polish little Megalodon teeth and mount them as shimmering pendants in unique, eye-catching necklaces. Fossil dealers usually sell their Megalodon fossils one tooth or necklace at a time, but there are exceptions. In April 2009, the worldfamous auction house Christie’s conducted its third annual Natural History exhibit and auction in its Paris gallery. Displayed alongside spectacular fossilized skeletons of an ichthyosaur (an extinct marine reptile) and other prehistoric animals were the amazingly lifelike reconstructed jaws of a large Megalodon. (Reconstructed Megalodon jaws are models made of fiberglass.) Adorned with 168 fossil teeth, the huge, wide-open jaws stood 7.2 feet (2.2 m) tall and had an estimated value of well over $200,000. Although Christie’s sold the ichthyosaur skeleton for an impressive $242,652, no one bought the Megalodon jaws; those pricey teeth apparently threatened to take too big a bite out of fossil collectors’ wallets.
pretty darned good at keeping secrets, which is why some people continue to believe that there is at least one more great big secret lurking in the depths of the deep blue sea: a 50-foot-long (15 m) locomotive with a mouth full of butcher knives. What do you think?
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Glossary Abyss A bottomless or very great depth Ampullae of Lorenzini A network of tiny structures, located
in the skin of the head and lower jaw, that detect weak electrical fields, such as those produced by the contracting muscles of other animals
A small fin located on a fish’s ventral surface, near the base of the tail; it helps to stabilize the fish as it swims.
Anal fin
A molecule produced by a living organism (for example, hemoglobin, the oxygen-carrying molecule in blood cells)
Biomolecule
Blade The triangular top portion of a shark tooth, above the root of the tooth
Bourrelet A scarlike mark on the side of the some shark teeth, located between the root and blade
A disguise that helps an animal blend in with its surroundings in order to avoid detection
Camouflage
The tail fin of a fish that is used to propel the fish through the water
Caudal fin
Cementum A gluelike material that attaches the outer enamel layer to the inner dentine layer of a tooth
Circumstantial evidence Evidence that relates to the subject under investigation in a roundabout or indirect way
Clasper The part of a pelvic fin of male sharks and rays that
is modified into a long, fingerlike projection used to introduce sperm into a female’s cloaca
Class One of the levels of taxonomic classification of organ-
isms; a class is composed of closely related taxonomic orders, and closely related classes are in turn grouped together into a phylum. A chamber or cavity beneath the ventral surface of a shark’s body (also found in other fishes, amphibians, and
Cloaca
86
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Glossary
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reptiles) that receives waste from the digestive system, and sperm, eggs, or live young from the reproductive system; these products exit the body through the cloacal opening located between the pelvic fins.
Compress To squeeze or squish together Countershading A color pattern in which a fish’s dorsal surface is dark in color, and its ventral surface is light in color; this pattern makes the fish difficult to detect whether viewed from above or below.
Credibility The state of being believable or reliable Crossopterygian A primitive lobe-finned fish, such as the
coelacanth, that possesses fleshy, lobe-shaped fins; crossopterygians evolved hundreds of millions of years ago and are believed to be the ancestors of amphibians.
Crustacean A type of invertebrate that has a hard shell and jointed limbs (for example, shrimp, crabs, and lobsters)
Cryptid A “hidden” animal that some people believe exists,
even though there is insufficient evidence to prove its existence
Cryptozoology The study of unknown or “hidden” animals Dentine A hard, bony layer in a tooth, located between the outer enamel layer and the inner pulp
Dispersed Scattered or spread out in different directions Dorsal Upper or top; used here to refer to the upper surface or “back” of an animal
A large single, or unpaired, fin on the back of a fish that helps stabilize the fish when it swims; some fishes possess a second, smaller dorsal fin farther along the back, near the tail fin.
Dorsal fin
Electrosense A sensory system that can detect electrical fields produced by the cells of living animals
Enamel The thin, outermost, extremely hard layer of a tooth Epoch The smallest division of the geological time scale;
epochs divide geological periods into shorter “chunks” of time.
Era The largest of the divisions of the geological time scale;
each era is composed of smaller divisions called periods, some
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Glossary of which are in turn composed of even smaller divisions called epochs.
Extinct No longer in existence Family One of the levels of taxonomic classification of organ-
isms; a family is composed of closely related genera, and closely related families are in turn grouped together into an order.
Filter feeder An organism that feeds on much tinier organisms that it strains out of the water
Fossil A preserved or mineralized body part or trace (such as a
footprint), found in sedimentary rock; the process of becoming a fossil is called fossilization, and an object that has become a fossil is said to have fossilized. One of the levels of taxonomic classification of organisms; a genus is composed of closely related species, and closely related genera are in turn grouped together into a taxonomic family.
Genus (plural: genera)
A scale or table that divides Earth’s history into shorter, more manageable blocks of time; this history is divided into eras, which are composed of smaller periods, which are, in turn, composed of even smaller epochs.
Geological time scale
A feathery-looking respiratory (breathing) organ that extracts life-giving oxygen from the water
Gill
A stiff, comblike structure in a gill that strains small food organisms from water as it passes through the gills
Gill raker
An opening along the side of the head of a shark where water that has entered the mouth exits from the body after passing through the gills
Gill slit
Ichthyologist A scientist who studies fishes Invertebrate An animal without a backbone (for example, worms, insects, and crustaceans)
One of the levels of taxonomic classification of organisms; a kingdom is composed of closely related phyla.
Kingdom
Lateral line A sensory system in fishes that detects changes in water pressure; it is composed of a network of pressure-sensitive nerve cells (neuromasts) on the head and sides of the fish.
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Glossary
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Leviathan A huge creature Marine biologist A scientist who studies life in the ocean Marker buoy A float that is attached to lobster traps or other objects on the sea floor by means of a mooring line; the buoy signals the location of the objects, which would otherwise be difficult or impossible to see beneath the surface.
Migration Traveling from one region to another with the change in the seasons.
A rope that connects an object on the sea floor, such as a lobster trap, to a marker buoy floating on the surface above
Mooring line
A tiny chamber connected to a shark’s nostril that contains sensory cells that can detect biomolecules, such as blood, in the water
Nasal capsule
Neuromast A pressure-sensitive nerve cell found in the lateral line system
Order One of the levels of taxonomic classification of organ-
isms; an order is composed of closely related taxonomic families, and closely related orders are in turn grouped together into a class.
Paleontologist A scientist who studies fossils Pectoral fin One of the paired fins equivalent to arms that are used for steering and maintaining balance
One of the paired fins equivalent to legs, located near the opening of the cloaca; in male sharks, the pelvic fins are modified into fingerlike structures called claspers, which are used to introduce sperm into the female’s cloaca.
Pelvic fin
Period One of the divisions of the geological time scale; a
period may be composed of two or more smaller divisions called epochs, and two or more periods may be combined into a larger division known as an era.
One of the levels of taxonomic classification of organisms; a phylum is composed of closely related classes, and closely related phyla are in turn grouped together into a kingdom.
Phylum (plural: phyla)
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Glossary
Pinniped A seal or sea lion Plankton Tiny organisms that float or drift about in the water Predator An organism that eats other organisms Pristine As something was in its original state Pulp The spongy, innermost part of a tooth; the pulp of a living tooth contains small blood vessels and nerve cells.
Quarry The animal chased in a hunt Reconstructed Made over or rebuilt to look like the original Rendezvous A meeting place Retina The light-sensitive inner layer of the eye Rookery A breeding area for animals that live in groups; some
seals and sea lions breed by the hundreds on rocky rookeries in the ocean. The portion of a tooth that is beneath the blade and attached to the jaw
Root
Sedimentary rock A rock formed by the settling and com-
pacting of soil particles, stones, mud, and silt on the bottom of rivers, lakes, and oceans
A structure in the ear that helps an animal to maintain balance and coordinate movement
Semicircular canal
A particular type of organism, such as a great white shark; closely related species are grouped together into a genus.
Species
A small opening behind a shark’s eye; water entering the spiracle passes over the gills and then exits through the gill slits.
Spiracle
A special structure in the back of the eye that reflects light onto light-detecting cells of the retina, allowing an animal to see in very dim light
Tapitum lucidum
Taxonomist A scientist who classifies organisms Trawling net A huge fishing net that is dragged along the bottom of the ocean, scooping up fishes, crabs, and other organisms that live on or near the seabed
Lower or bottom; used here to refer to the lower or “belly” surface of an animal
Ventral
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Glossary
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An animal with a backbone; fishes, amphibians, reptiles, birds, and mammals are all vertebrates.
Vertebrate
To be worn away by exposure to wind, rain, sunlight, freezing, and thawing, etc.
Weather
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BiBlioGraPhy bOOks AND ArTIcLEs
Benchley, Peter. Jaws. New York: Random House, 1974. Bright, Michael. The Private Life of Sharks: The Truth Behind the Myth. Mechanicsburg, PA: Stackpole Books, 2000. Budker, Paul. The Life of Sharks. New York: Columbia University Press, 1971. Burton, Robert. The Life and Death of Whales. New York: Universe Books, 1980. Cartmell, B. Clay. Let’s Go Fossil Shark Tooth Hunting. Ann Arbor, Mich.: Natural Science Research, 1978. Colbert, Edwin H. Evolution of the Vertebrates. New York: John Wiley and Sons, 1980. Crichton, Michael. Jurassic Park. Universal City, Calif.: Universal Studios, 2000. Ellis, Richard, and J. McCosker. Great White Shark: The Definitive Look at the Most Terrifying Creature of the Ocean. Stanford, Calif.: Stanford University Press, 1991. Futuyama, Douglas J. Evolution. (Sunderland, Mass.: Sinauer Associates, 2005.) Gramling, Carolyn. “Scariest Sharks, Then and Now, Only Distant Cousins.” Earth 54 (2009): 13. Greenwell, J. Richard, editor. “Second Megamouth Shark Found,” ISC Newsletter 4, No. 1 (1985): 5. Heuvelmans, Bernard. “What is Cryptozoology?” Cryptozoology 1 (1982): 1–12. ———.. “The Birth and Early History of Cryptozoology.” Cryptozoology 3 (1984): 1–30. Klimley, A. Peter. The Secret Life of Sharks. New York: Simon and Schuster, 2003.
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bibliography
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Martin, Robert A. Missing Links: Evolutionary Concepts and Transitions Through Time. Sudbury, Mass.: Jones and Bartlett, 2004. Melville, Herman. Moby Dick. Cutchogue, N.Y.: Buccaneer Books, 1976. Musick, John A., and B. McMillan. The Shark Chronicles: A Scientist Tracks the Consummate Predator. New York: Henry Holt, 2002. Renz, Mark. Megalodon: Hunting the Hunter. Lehigh Acres, Fla.: PaleoPress, 2002. Stead, David George. Sharks and Rays of the Australian Seas. Sydney, Australia: Angus and Robertson, 1963. Taylor, Leighton (ed.), T.C. Tricas, K. Deacon, P. Last, J.E. McCosker, and T.I. Walker. The Nature Company Guides: Sharks and Rays. McMahons Point, Australia: Time-Life Books, 1997. Weinberg, Samantha. A Fish Caught in Time: The Search for the Coelacanth. New York: Harper Collins, 2000.
WEb sITEs
“Arts décoratifs du XVIème au XIXème Siècle et Histoire Naturelle.” Christies.com. Available online. URL: http://www. christies.com/LotFinder/searchresults.aspx?intSaleID=22513# action=paging&intSaleID=22513&sid=69a30032-8b2d-47508841-2cadcfe4c887&pg=1. Accessed November 20, 2009. Bruner, John Clay. “The Megatooth Shark, Carcharodon megalodon: Rough Toothed, Huge Toothed.” Florida Museum of Natural History. Available online. URL: http://flmnh.ufl.edu/ fish/sharks/InNews/megatoothshark.htm. Accessed October 7, 2009. Collier, Ralph S. “White Shark Interactions with Inanimate Objects.” Shark Research Committee. Available online. URL: http://www.sharkresearchcommittee.com/inanimate.htm. Accessed October 7, 2009.
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bibliography “Great White Shark Swims 12,400 Miles, Shocks Scientists.” Mongabay.com. Available online. URL: http://news.mongabay. com/2005/1006-wcs.html. Accessed November 29, 2009. Kaplan, Matt. “Unique Orca Hunting Technique Documented.” Nature.com. Available online. URL: http://www.nature.com/ news/2007/071214/full/news.2007.380.html. Accessed November 16, 2009. “Killer Whales: Diet and Eating Habits.” Seaworld.org. Available online. URL: http://www.seaworld.org/infobooks/killerwhale/ dietkw.html. Accessed November 16, 2009. Kowinsky, Jayson. “The Size of Megalodons.” FossilGuy.com. Available online. URL: http://www.fossilguy.com/topics/ megsize/megsize.htm. Accessed October 7, 2009. Mackenzie, James. “Giant shark, dinosaur remains on sale in Paris.” Reuters.com. Available online. URL: http://www.reuters. com/article/lifestyleMolt/idUSTRE5352QB20090406?feedType =RSS&feedName=lifestyleMolt. Accessed November 20, 2009 Martin, R. Aiden. “Biology of Sharks and Rays: The Extinction of Megalodon.” ReefQuest Centre for Shark Research. Available online. URL: http://www.elasmo-research.org/education/ evolution/megalodon_extinction.htm. Accessed October 7, 2009. ———. “Biology of Sharks and Rays: Paleoecology of Megalodon and the White Shark.” ReefQuest Centre for Shark Research. Available online. URL: http://www.elasmo-research.org/ education/evolution/paleoecology.htm. Accessed October 7, 2009. ———. “Biology of Sharks and Rays: Reconstructing Megalodon.” ReefQuest Center for Shark Research. Available online. URL: http://www.elasmo-research.org/education/evolution/ reconstruct_megalodon.htm. Accessed October 7, 2009. “Megalodon Teeth.” Arizonaskiesmeteorites.com. Available online. URL: http://www.arizonaskiesmeteorites.com/ Megalodon_Shark_Tooth_Teeth/. Accessed November 20, 2009.
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bibliography
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“MegaTeeth: Museum Quality Megalodon Shark Teeth.” Megateeth.com. Available online. URL: http://www.megateeth.com/. Accessed November 20, 2009. Ravalli, Richard J., Jr. “Does Carcharodon megalodon Still Exist?” StrangeMag.com. Available online. URL: http://www.geocities. com/Area51/Aurora/4746/stillexist.html. Accessed October 7, 2009. Roesch, Ben S. “A Critical Evaluation of the Supposed Contemporary Existence of Carcharodon megalodon.” Cryptozoology Review. Available online. URL: http://web.ncf.ca/bz050/ megalodon.html. Accessed October 7, 2009. Schwartz, Mark. “Great White Sharks migrate thousands of Miles Across the Sea, New Study Finds.” Stanford Report. Available online. URL: http://news.stanford.edu/news/2002/january9/ sharks-19.html. Accessed November 16, 2009. “Steve’s Fossil Shark Teeth: Museum Quality Megalodon Teeth and Other Fossil Specimens.” Megalodonteeth.com. Available online. URL: http://www.Megalodonteeth.com/. Accessed November 20, 2009. “Tags Reveal White Sharks have neighborhoods in the North Pacific, Stanford Researchers Say.” Stanford.edu. Available online. URL: http://news.stanford.edu/news/2009/november2/ white-shark-research-110309.html Accessed November 29, 2009. Turner, Pamela S. “Showdown at Sea.” National Wildlife. Available online. URL: http://www.nwf.org/nationalwildlife/ printerFriendlycfm?issueID=70&articleID=991. Accessed November 16, 2009.
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further resourCes bOOks
Busbey, Arthur B. III, Robert R. Caenraads, Paul Willis, and David Roots. The Nature Company Guides: Rocks and Fossils. Sydney, Australia: Time-Life Books, 1996. Casey, Susan. The Devil’s Teeth: A True Story of Obsession and Survival Among America’s Great White Sharks. New York: Henry Holt, 2005. Cox, Barry, R.J.G. Savage, Brian Gardner, Colin Harrison, and Douglas Palmer. The Simon & Schuster Encyclopedia of Dinosaurs and Prehistoric Creatures. New York: Simon & Schuster, 1999. Lambert, David. The Field Guide to Geology. New York: Diagram Visual Information, 1998. Macquitty, Miranda. Sharks and Other Scary Sea Creatures. London: Doring Kindersley, 2002. Parker, Steven, and Jane Parker. The Encyclopedia of Sharks. Willowdale, Ontario: Firefly Books, 2002. Stevens, John D. Sharks. New York: Facts on File, 1987. Stonehouse, Bernard. A Visual Introduction to Sharks, Skates and Rays. New York: Checkmark Books, 1999.
WEb sITEs Answers.com: Geological timescale http://www.answers.com/topic/geologic-timescale-table This site contains a very detailed version of the geological time scale, along with a history of its development by famous geologists such as James Hutton and Georges Cuvier. 96
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Coelacanth (Latimeria chalumnae) http://www.arkive.org/coelacanth/latimeria-chalumnae/ video-00.html Here you can find a lot of information about the biology of this rare fish; site includes video of a live coelacanth swimming in the ocean. Cryptozoology http://www.pibburns.com/cryptozo.htm This site provides detailed descriptions of dozens of famous cryptids, including Megalodon and many other hidden animals. FossilGuy.com http://www.fossilguy.com Look here to find information about fossils and fossil collecting, as well as lists of popular fossil collecting sites. Ichthyology at the Florida Museum of Natural History http://www.flmnh.ufl.edu/fish/default.htm This education-based site is loaded with information about shark biology, shark attacks, and shark conservation. Megamouth Shark (Megachasma pelagios) http://www.arkive.org/megamouth-shark/megachasma-pelagios/info.html This site contains lots of information about this unusual shark; also includes video of divers swimming with a live megamouth. ReefQuest Centre for Shark Research http://www.elasmo-research.org Here’s a Web site for a shark conservation organization that educates the public about the value of sharks and promotes research dealing with shark biology and conservation. Shark Research Committee. http://www.sharkresearchcommittee.com This Web site is devoted to sharks, especially species dangerous to man. It has a lot of information about the biology and behavior of the great white shark.
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PiCture Credits Page 11:© Stephen Frink Collection/Alamy 13:© W. Scott/ Shutterstock 16:© Christian Darkin/ Photo Researchers, Inc. 17:© Jeff Rotman/Alamy 18:© Infobase Publishing 22:© Jeff Rotman/Alamy 28:© Jeff Rotman/Alamy 32:© Stephen Frink Collection/Alamy 34:© Infobase Publishing 38:© AFP/Getty Images 41:© K Byrne/Alamy 45:© Roger Viollet/ Getty Images
54:© Christian Darkin/Photo Researchers, Inc. 57:© Infobase Publishing 59:© Gary Hincks/Photo Researchers, Inc. 61:© Francois Gohier/Photo Researchers, Inc. 69:© WaterFrame/Alamy 74:© Toru Yamanaka/AFP/ Getty Images 78: (top) © Stanislav Khrapov/ Shutterstock; (bottom) © Hallam Creations/ Shutterstock 82:© Gabriel Bouys/AFP/ Getty Images 84:© Bertrand Guay/AFP/ Getty Images
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index caudal fins, 19 cementum, 62 Cetorhinus maximus, 40–41 Christie’s Auction House, 85 Chupacabras, 7, 8 circumstantial evidence, 35 Cladoselache, 53–55, 56, 71 claspers, 19 classes, defined, 14 Cleveland Shales, 53–55 climate, in Miocene Epoch, 56–58 cloaca, 19 coast guard cutters, 43–44 coelacanths, 70–73, 77 Collier, Ralph S., 48–50 coloration of boat hulls, 48–49 of fossilized teeth, 63 of great white sharks, 29–33, 80 of whale sharks, 38–39, 80 Comoros Islands, 73, 77 competition, 48–49, 66 countershading, 32, 80 Courtenay-Latimer, Marjorie, 70–72, 73, 77 crayfish men, 24–26, 33, 80–81 Crichton, Michael, 68 crossopterygians, 71, 72 cryptids, defined, 6 cryptozoology, overview of, 6–8 Cryptozoology Review, 33
A
AFB-14, 72–73 American Museum of Natural History, 17–18 ampullae of Lorenzini, 47 anaconda snakes, 7, 8 anal fins, 19 Australia crewmen’s tale and, 26–27, 34–35, 81 lobstermen’s tale and, 24–26, 34–35, 80–81 Nicole and, 76 Rachel Cohen attack and, 43–44, 83
B
basking sharks, 40–41, 42 Benchley, Peter, 10 Biology of Sharks and Rays web site, 17 biomolecules, 46 blade, 62 Block, Barbara, 75 blood, 46 boats, attacks on, 43–51, 83 bourrelet, 62 Bruner, John Clay, 55, 60 buoys, 33 Burns, John D., 48
C
camouflage, 31 Carcharocles genus, 13 Carcharodon carcharias, 9, 15, 18 Carcharodon megalodon, 9–10, 12–13, 15 cartilage, 42 Cartmell, B.C., 26–27, 33–34, 81
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D
99
deep water, 75–77 dentine, 62–63 Devonian Cleveland shales, 53–55
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Index Devonian Period, 56, 72 dorsal fins, 19
E
ears, 46 electrosense, 47–48 Ellis, Richard, 45–48, 63, 74–75 enamel, 62, 85 epochs, 56 eras, 56 Erie, Lake, 53 Eschritius robustus, 58–60 eyes, 46, 72
F
families, defined, 14 Farallon Islands, 65, 66, 75 filter feeders, 37, 40, 42, 73 fins, 17, 19, 38 A Fish Caught in Time: The Search for the Coelacanth (Weinberg), 71 formulas, mathematical, 20, 27–29, 30–31, 81 fossil record Cladoselache and, 53–55 geological time scale and, 56–57 teeth, jaws and, 13, 15–21, 62–63, 84–85
G
genera, defined, 14 geological time scale, 56–57 gill rakers, 42 gill slits, 19 gills, 19, 42 glaciers, 60–61 gombessa, 77 Goosen, Hendrick, 70–72 gorillas, 77 Gottfried, Michael, 20, 27, 30–31, 50–51, 81
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gray whales, 58–60 Great Barrier Reef, 26–27, 35 Great White Shark (Ellis and McCosker), 45, 63, 74–75 great white sharks anatomy of, 18 boat attacks by, 44–50 coloration of, 29–33, 80 migration of, 75–77 orcas and, 64–66 overview of, 10–12 shallow water and, 60 taxonomy of, 15 teeth of, 21 Grey, Loren, 39–41, 81 Grey, Zane, 36–39, 81
h
hearing, 46 hearsay evidence, 34, 51 hemoglobin, 46 Heterodontus francisci, 21 Heuvelmans, Bernard, 6 hippos, pygmy, 77 hornsharks, 21 hull coloration, 48–49
I
Ice Age, 60–61, 66–67, 83 ice rafts, 64 ichthyologists, 12 ichthyosaur skeleton, 85 Isurus genus, 13 Isurus oxyrinchus, 21
j
jaws, 13, 15–21, 19, 85 Jaws (Benchley), 10 Jurassic Park (Crichton), 68
K
killer whales, 61–66, 75 kingdoms, defined, 14
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Index Klimley, Peter, 49–50 Kongamato, 7
L
lateral lines, 47 Latimeria chalumnae, 72 Le Boeuf, Burney, 76 Let’s Go Fossil Shark Tooth Hunting (Cartmell), 26–27, 33–34 lobster fishermen, 24–26, 33, 80–81 Loch Ness Monster, 6 Lorenzini, ampullae of, 47
M
MacLeod, John, 48 mako sharks, 13, 21 Marine and Coastal Management Department of South Africa, 76 marine biologists, 10 marker buoys, 33 Martin, R. Aldan, 17 mass extinctions, 56 Maunganui (S.S.), 39–41 McCosker, John E., 45–48, 63 Megachasma pelagios, 73 Megalania, 7 megamouth, 72–75 Melville, Herman, 33 Mesoteras, 55 migration, 58, 75–77 Miocene Epoch, 56–58 Moby Dick, 33 Mokele-mbembe, 8 mooring lines, 33 motion, detection of, 47 mountain gorillas, 77
N
Namu, 62 nasal capsules, 46 Nerine, 70–72, 73
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neuromasts, 47 Nicole (shark), 76 night vision, 46 nomenclature, scientific, 14–15 nose, 18 nostrils, 18–19, 46
O
orcas, 61–66, 75 Orcinus orca, 61–66 orders, defined, 14
P
Palmer, Ernest, 45–46 panda bears, 77 pectoral fins, 19, 38 pelvic fins, 19 periods, 56 phyla, defined, 14 pinnipeds as prey, 10, 22, 29–30, 64, 76 plankton, 40, 42, 81 Pleistocene Epoch, 60–61 Point Reyes Bird Observatory, 65 pop-up tags, 66, 75, 76 propellers, 45–46, 48 pulp, 62 pygmy hippos, 77 Pyle, Peter, 65, 75
R
Rachel Cohen attack, 43–44, 50–51, 83 references, 33 reptiles, 72 retina, 46 Rhincodon typus, 20–21 Ri, 8 right whales, 55 rocks, 56–57 Roesch, Ben, 33, 40, 43–44 rookeries, 30
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Index roots, 62 Ropen, 7
S
Schulman-Janiger, Alisa, 65 scientific nomenclature, 14–15 sea anchors, 72–73 sea level, 57–58, 60–61 sedimentary rocks, 56–57, 58, 63 semicircular canals, 46 senses, 46–48 Shamu, 62 Shark Research Committee, 48–49 sharks. See also Specific sharks external anatomy of, 18–19 megamouth, 72–75 as prey of orcas, 64–66 Sharks and Rays of Australian Seas (Stead), 24–26, 81 size predictions, 19–21, 30–31, 50–51, 81 skin, 47 smell, 46 Smith, James L.B., 70–71 snouts, 18–19, 37, 40–41 South Pacific, 36–41 species, defined, 14 spiracles, 19 Stead, David G., 24–26, 33, 81 Sucuriju, 7, 8
T
tail slapping, 49–50 tapetum lucidum, 46 tapirs, 77 Tasmanian wolf, 7 taste buds, 47
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taxonomy, overview of, 14–15 teeth attack on boat and, 44 calculation of body length from, 20, 30–31, 50–51, 81 formula for calculation of size of, 27–29, 31 fossilized, 62–63, 67, 84–85 of great white sharks, 10–11, 12–13 of Megalodon, 12–13 Rachel Cohen attack and, 43–44, 50–51, 83 sale of fossilized, 84–85 study of, 15–21 territoriality, 48–49 thunderbird, 8 thylacine, 7 time scale, geological, 56–57 Tipfin, 66, 75 tongue, 47 touch, 47 trawling nets, 70 Tuna Research and Conservation Center, 75
V
vertebrates, 71 vision, 46
W
weathering, 63 Weinberg, Samantha, 71 whale sharks, 20–21, 37, 39–42, 81 whalers, 58–59 whales as prey, 22–23, 55, 58–60 wolves, 64
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aBout the author RICK EMMER is a substitute science and math teacher for the Avon Lake City School District in northeast Ohio. He was previously an aquarist at the Cleveland Aquarium and a zookeeper at the Cleveland Metroparks Zoo. He has a bachelor’s degree in biology from Mount Union College and a master’s degree in biology from John Carroll University. He was a member of the International Society of Cryptozoology for several years. Emmer lives with his family in Bay Village, Ohio, smack dab in the middle of Cryptid Country, with the lair of the Lake Erie Monster to the north and the hideout of the Grassman, Ohio’s Bigfoot, to the south.
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