Megalodon Fact or Fiction

creature scene investigation

Megld Fact or Fiction?


Bigfoot: Fact or Fiction? Fict ion? Giant Anaconda Anaconda and Other Cryptids: Fact or Fiction? Fict ion? Kraken: Fact or Fiction? Loch Ness Monster: Fact or Fiction? Megalodon: Megalodo n: Fact or Fiction? Mokele-mbembe: Mokele-m bembe: Fact or Fiction?


Megld Fact or Fiction?

Rick Emmer

MEGALODON: FACT OR FICTION?

Copyright © 2010 by Inobase Publishing All rights reserved. No part o this book may be reproduced or utilized in any orm or by any means, electronic or mechanical, including photocopying, recording, or by any inormation storage or retrieval systems, without permission in writing rom the publisher. For inormation, contact: Chelsea House An imprint o Inobase Publishing 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Emmer, Rick. Megalodon: act or fction? / Rick Emmer. p. cm. — (Creature scene investigation) Includes bibliographical reerences and index. ISBN 978-0-7910-9777-9 (hardcover) ISBN 978-1-4381-3210-5 (e-book) 1. Carcharocles megalodon—Juvenile literature. I. itle. II. Series. QL89.2.C37E46 2010 567'.3—dc22 2009011461

Chelsea House books are available at special discounts when purchased in bulk quantities or 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 fnd Chelsea House on the World Wide Web at http://www.chelseahouse.com. ext design by James Scotto-Lavino, Erik Lindstrom Cover design by akeshi akahashi Composition by EJB Publishing Services Cover printed by Bang Printing, Brainerd, MN Book printed and bound by Bang Printing, Brai nerd, MN Date printed: March 2010 Printed in the United States o America 10 9 8 7 6 5 4 3 2 1 Tis book is printed on acid-ree paper. All links and Web addresses were checked and verifed to be correct at the time o publication. Because o the dynamic nature o 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

24

3 Like Father, Like Son

36

4 Things That Go Bump

in the Night

43

5 A Long-Lost World

53

6 Mysteries from the Deep Blue Sea

68

7 Final Report: Megalodon

80

Glossary

86

Bibliography

92

Further Resources

96

Picture Credits

98

Index

99

About the Author

103

5

PrefaCe elcome to Creature Scene Investigation: Te Science o Cryptozoology, the series devoted to the science o cryptozoology . Bernard Heuvelmans, a French scientist, invented that word 50 years ago. It is a combination o the words kryptos (Greek or “hidden”) and zoology, the scientifc study o animals. So, cryptozoology is the study o “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) ollow a long, two-step process as they search or cryptids. First, they gather as much inormation about their animal as they can. Te most important sources o inormation are people who live near where the cryptid supposedly lives. Tese people are most amiliar with the animal and the stories about it. So, or example, i cryptozoologists want to fnd 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. I they want to learn about Bigoot, they should talk to people who ound its ootprints or took its photo. A cryptozoologist careully examines all o this inormation. Tis is important because it helps the scientist identiy and rule out some stories that might be mistakes or lies. Te remaining inormation can then be used to produce a clear scientifc description o the cryptid in question. It might even lead to solid proo that the cryptid exists. Second, a cryptozoologist takes the results o his or her research and goes into the feld to look or solid evidence that the cryptid really exists. Te best possible evidence would be

W

6

Megalodon: The Fisherman’s Nightmare Preface

an actual specimen—maybe even a live one. Short o that, a combination o good videos, photographs, ootprints, body parts (bones and teeth, or example), and other clues can make a strong case or a cryptid’s existence. In this way, the science o cryptozoology is a lot like orensics, the science made amous by all o those crime investigation shows on V. Te goal o orensics detectives is to use the evidence they nd to catch a criminal. Te goal o cryptozoologists is to catch a cryptid—or at least to nd solid evidence that it really exists. Some cryptids have become world-amous. Te most amous ones o all are probably the legendary Loch Ness Monster o Scotland and the apelike Bigoot o the United States. Tere are many other cryptids out there, too. At least, some people think so. Tis series explores the legends and lore—the acts and the ction—behind the most popular o all o the cryptids: the gigantic shark known as Megalodon, Kraken the monster squid, an Arican dinosaur called Mokele-mbembe, the Loch Ness Monster, and Bigoot. Tis series also takes a look at some lesser-known but equally ascinating cryptids rom around the world: •

•

•

•

•

the mysterious, blood-sucking Chupacabras, or “goat sucker,” rom the Caribbean, Mexico, and South America the Sucuriju, a giant anaconda snake rom South America Megalania, the gigantic monitor lizard rom Australia the Ropen and Kongamato, prehistoric fying reptiles rom Arica and the island o New Guinea the thylacine, or asmanian wol, rom the island o asmania

7

8

MEGALODON: Fact or Fict ion?

•

•

the Ri, a mermaidlike creature rom the waters o New Guinea the thunderbird, a giant vulture rom western North America

Some cryptids, such as dinosaurs like Mokele-mbembe, are animals already known to science. Tese animals are thought to have become extinct. Some people, however, believe that these animals are still alive in lands that are difcult or most humans to reach. Other cryptids, such as the giant anaconda snake, are simply unusually large (or, in some cases, unusually small) versions o modern animals. And yet other cryptids, such as the Chupacabras, appear to be animals right out o a science ction movie, totally unlike anything known to modern science. As cryptozoologists search or these unusual animals, they keep in mind a couple o slogans. Te rst is, “I it sounds too good to be true, it probably isn’t true.” Te second is, “Absence o proo is not proo o absence.” Te meaning o these slogans will become clear as you observe how cryptozoologists analyze and interpret the evidence they gather in their search or these awesome animals.

1 Megalodon: The Fisherman’s Nightmare Te really terrifc 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 eet long. . . . Look, the Latin name or this fsh is Carcharodon carcharias , okay? Te closest ancestor we can fnd or it is something called Carcharodon megalodon , a fsh that existed maybe 30,000 or 40,000 years ago. We have ossil teeth rom Megalodon. Tey’re six inches long. Tat would put the fsh at between 80 and 100 eet. And the teeth are exactly like the teeth you see in great whites today. What I’m getting at 9

10


is, suppose the two fsh are really one species. What’s to say Megalodon is really extinct? Why should it be? Not lack o ood. I there’s enough down there to support whales, there’s enough to support sharks that big. Just because we’ve never seen a 100-oot white doesn’t mean they couldn’t exist. . . . Can you imagine what it could do, what kind o power it would have? . . . It would be like a locomotive with a mouth ull o butcher knives. —Peter Benchley, Jaws

reat . . . white . . . shark. . . . Odd, isn’t it? Tis string o three little words is scary enough to make any beachgoer think twice beore wading into the water. Tat’s due in no small part to one other little word: Jaws. Tis 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 o Amity, New York, a quiet little tourist town on the Atlantic seaboard. Tis action-packed story o man versus man-eating monster is enough to convince anybody that the great white shark must be one o the most terriying predators to ever swim the seven seas. Te great white shark is one powerul predator. Capable o growing to a length o more than 20 eet (approximately 6 meters) and weighing more than two tons (1,800 kilograms), this huge fsh sits—or rather, swims—atop the ocean ood chain. Roaming cool coastal waters between the warm tropics and the rigid polar seas, this shark is constantly on the prowl or prey: fshes, pinnipeds (seals and sea lions), dolphins, and porpoises. When a great white shark attacks, it makes quick work o its victim. One marine biologist (a scientist who studies lie in the ocean) once saw a great white attack a 200-pound (91 kg), 6-oot-long (1.8 m) harbor seal. It took only fve

G

Megalodon : The Fisherman’s Nightmare

Te 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 or the shark to kill and eat its prey. Afer three huge bites, the seal was gone. Deep-sea shermen have actually caught 20-oot (6-m) great whites on rod and reel. Tink about what a trophy the jaws o such a monster make: a mouth that is a oot and a hal (0.5 m) wide, lined with knie-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 saely land a sh that big, strong, and dangerous.

11

12

MEGALODON: Fat o Fit ion?

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, dwaring the relatively puny 2-inchers ound on a 20-oot shark. What a colossal monster that would be. A white shark the size o a whale, with a mouth so big it could swallow basketball star Shaquille O’Neal in one bite. o snag such a beast would surely be a sherman’s worst nightmare. Could such a monster really exist? Yes. INTrODucING MEGALODON Carcharodon megalodon is the name scientists have given this gigantic version o the great white shark. Over the years, many ossilized teeth o Carcharodon megalodon—usually just called Megalodon, which is Greek or “mighty tooth”— have been discovered and careully dug out o sedimentary rocks. Hundreds more have been scooped up rom the bottom o the ocean. Te largest Megalodon tooth ever ound 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 o the white shark, their shape is almost identical: at triangles with saw-tooth serrations along both sides. In act, the teeth o these two species o shark are so similar that ichthyologists (scientists who study sh) 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 o these leviathans , we won’t know or 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 o these two shes are diferent enough—Megalodon teeth have relatively smaller serrations along the edges and possess

Megalodon: The Fisherman’s Nightmare

Tis 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 diferent genus, Carcharocles . Tis theory is strengthened by the recent discovery o a rare, complete fossil jaw o an ancestor o the great white shark. Te size and arrangement o the teeth in this 5-million-year-old ossil 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.

13

14


What’s In a Name? cientists who classiy organisms are called xooi. axonomists place each kind o organism within a seven-level system o classifcation. Te smallest unit in this system is the pci. A species is what we normally recognize as a particular type o organism: a muskrat, a bald eagle, a great white shark, or a Megalodon. Closely related species are grouped together in the next level o classifcation, the gu. Closely related genera (the plural o genus) are grouped together into a fily ; similar amilies are grouped together into an ordr ; similar orders into a cl ; similar classes into a pylu ; and fnally, similar phyla (the plural o phylum) into a kigdo. Te complete classifcation o Megalodon is as ollows:

S

Kingdom: Animalia Phylum: Chordata Class: Chondrichthyes Order: Lamniormes Family: Lamnidae Genus: Carcharodon Species: megalodon

Unortunately, most shark experts doubt that anyone ever will catch a live Megalodon. Tey think the huge shark is probably extinct; afer all, no one has ever laid hands on one, living or dead. Nevertheless, scientists have been able to draw a pretty detailed picture o what Megalodon probably looked like and how it probably lived. Tey’ve been able to do this by studying ossils o extinct sharks and by analyzing the appearance and behavior o modern-day

Megalodon: The Fisheman’s Nightmae

15

When reerring to a particular organism, scientists normally just use its genus and species names. Tese names are written in italics , and the only letter that is capitalized is the frst letter o the genus name. Megalodon’s ormal name is thereore Carcharodon megalodon. Te act 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. (Scientifc names are obtained rom Latin and Greek words.) No two species are allowed to have the same scientifc name. As a result, this system o classifcation not only shows how closely related two species are, it also guarantees that one person knows exactly which species another person is talking about. Tis is a defnite advantage over the use o nicknames. For example, although great white shark, white pointer, white shark, white death, great white, and man-eater are all nicknames or the same fsh, not everyone is amiliar with them all, and some people use the term “man-eater” to reer to any species o shark known to kill and eat people (such as the mako). I someone reers to Carcharodon carcharias , however, the identity o the critter is crystal clear.

sharks, especially Megalodon’s little cousin, the great white. Te picture that scientists have painted is impressive, to say the least.

reconstucting 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

16


A Megalodon shark ( Carcharodon megalodon) is pictured above the much smaller great white shark ( Carcharodon carcharias). Te 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. Tey 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. Tis

Megalodon : The Fisherman’s Nightmare

17

would indicate that the rest o the skull—and thereore the whole head—would also be more massive. Tis evidence, in turn, would mean that Megalodon’s pectoral ns would also be larger and sturdier, to help support and steer the shark’s “top-heavy” ront end as it moved through the water. Te overall efect, as shark expert R. Aldan Martin explains on his Biology o Sharks and Rays Web site, would be “sort o a great white on steroids.” Just how big did Megalodon grow? Back in the early 1900s, a model o the jaws o a Megalodon was put on exhibit at the American Museum o Natural History in New York City. Te Megalodon ossil teeth used in this model were obtained rom several diferent places (and, thereore, rom several

Tis model approximates the size of the megalodon jaw. Clearly, Megalodon was one of the most ferocious predators to ever roam the sea.

18


diferent sharks). Using the number o teeth present in the jaws o a great white shark (about 24 in each jaw, excluding the hundreds o reserve teeth waiting to replace those that

Let’s Get Technical: External Anatomy of Sharks

uring the course o this investigation, it will be necessary to compare Megalodon with other shark species. In order to do this efectively, it is necessary to be amiliar with some o the visible body parts o sharks. With that in mind, let’s take a whirlwind tour o the external anatomy o the shark that probably looks the most like Megalodon: Carcharodon carcharias , the great white shark. At the business end o the white shark is the tapered, pointed snout, the equivalent o a nose. Like most noses, the white shark’s nose has a pair o nostrils, located on the ventral (bottom) surace

D

Te anatomy of the great white shark is perfectly designed for strength and speed. Te anatomy of Megalodon was likely very much like that of the great white.


19

break of), museum artists ended up creating a set o jaws 10 eet (3 m) wide. A Megalodon with this monstrous mouth would have been close to 100 eet (30 m) long!

o the snout, a short distance in back o the snout tip. Te eyes are located a little urther back, on the sides o the head. Te mouth, with its tooth-studded jaws, is located directly beneath the eyes, on the ventral surace o the head. Along each side o the shark’s neck are ve 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 fow through the gills. Fast swimmers such as the great white oten do not have spiracles. Tey supply their gills with enough oxygenated water just by swimming with their mouth open.) Te shark’s equivalent o arms is its pair o pectoral ns, which are used or steering. Tey are located on the sides, behind and below the gill slits. Te white shark’s trademark is its large, triangular rst dorsal fn , located on the dorsal (upper) surace. Tere is an inconspicuous second dorsal n located arther back, near the base o the tail. A small anal fn is located on the ventral surace, also near the base o the tail. Te dorsal and anal ns help stabilize the shark as it moves through the water. Te crescent-shaped caudal fn at the rear helps propel the shark through the water. Finally, small, paired pelvic fns are located ventrally, ar back on the belly, on either side o the opening or the cloaca , a chamber that collects products o the digestive and reproductive systems beore they exit the body. It’s easy to tell the sex o any shark: Each o a male’s pelvic ns has a long, ngerlike projection called a clasper that is used to introduce sperm into the emale’s cloaca during breeding. Scientists believe the claspers o a ull-grown male megalodon would have been 5 eet (1.5 m) long.

20


Several years later, however, scientists realized that these model jaws were too big. A close look at the jaws o a great white reveals that the teeth are not all the same size: Te teeth at the ront o the jaws are bigger than the ones along the sides and at the back. Te ossil Megalodon teeth used in the original museum model were all big ront teeth. (Remember, the teeth were obtained rom several sharks, not just one.) When scientists took tooth size diferences into account, they calculated that the jaws o the Megalodon model should have been only about 6 eet (1.8 m) wide, meaning that the shark was only 45 to 50 eet (13–15 m) long. Since then, more ossil teeth have been discovered, including a cluster o teeth rom a single shark. As a result, scientists are now able to make more accurate size predictions or megalodon. In act, one group o researchers, led by ossil-hunting paleontologist Michael Gottried, has come up with a mathematical ormula to determine how big the owner o a given ossil tooth must have been (this ormula works or the big ront teeth only.) Te ormula is: length of megalodon, in meters = (0.96 x [front-tooth height, in centimeters]) – 0.22 Te biggest Megalodon tooth discovered so ar is nearly 7 inches (18 cm) long. Tis means the length o the owner o that tooth would have been: length = (0.96 x 18) – 0.22 = 17.28 – 0.22 = 17.06 meters Tis calculated length o about 17 meters, or 56 eet, seems reasonable; it’s in the general neighborhood o the estimate the museum scientists came up with or their scaled-down version o Megalodon. What would a shark o this size weigh? Whale sharks (Rhincodon typus), the largest o all living sharks, grow


40–50 eet (12–15 m) long and weigh about 20 tons (18,000 kg), so ichthyologists eel that’s probably a good approximation o the weight o a megalodon o the same length. Tis was one big sh—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 o 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 diferent kinds o teeth are designed to do diferent things. ake the shortn mako shark (Isurus oxyrinchus), or example. Tis speedy shark eeds on squid and sh, which are slippery and hard to hold on to. A mako’s teeth are skinny and pointed, perect or poking into and latching on to such slick prey. Another shark, the hornshark (Heterodontus francisci), actually has two very diferent types o teeth to handle a variety o types o prey. Tis little shark, which spends most o its time resting on the seabed, has ront teeth that are small and pointed, perect or grabbing and holding on to slippery bottom-dwelling sh, and back teeth that are stubby and sturdy, perect or smashing the shells o sea urchins, crabs, and other crunchy prey. Te great white shark’s strong, sharp, serrated teeth are a gruesome giveaway as ar as its ood choice is concerned. Unlike most other sharks, which oen prey on animals smal l enough to be gulped down in one bite, white sharks—especially adults—preer to prey on marine mammals, which are usually much too large to be swallowed in one gulp. (Elephant seals, one o the great white’s avorite oods, can grow very large; an adult male can reach a weight o 5,000 pounds [2,300 kg]!) A white shark likes to remove big chunks o esh rom its large prey. Its teeth serve as both ork and knie. Te

21

22


Te 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 o a ork stabbing a piece o steak, while the serrated edges o the teeth cut through fesh and bone, like a heavy-duty steak knie. 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 preers pinnipeds, however, Megalodon probably hunted much larger prey, since most seals would be little more than an appetizer or that “locomotive with a mouth ull o butcher knives.” Whales would be the most likely main course on the menu. In act, some ossil whale bones with suspicious-looking scrape marks on them

Megalodon : The Fisheman’s Nightmae

have been dug up along with ossil Megalodon teeth, perhaps evidence o a deadly battle between two colossal beasts.

MODErN-DAy MEGALODON: FAcT Or FIcTION? Since the year 1918, a handul o 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 fsh and mistakenly identiy it as megalodon? Perhaps they saw nothing at all, and just made up a bunch o whopping fsh tales about “the big one that got away.” Since none o these eyewitnesses provided any direct, rock-solid evidence to back up their claims, all we have to go on is their stories. Tereore, 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 o evidence obtained at the scene o some dastardly deed. It’s time to perorm a creature scene investigation!

23

2 One Whale of a Fish Story here are ve recorded eyewitness accounts o possible Megalodon sightings. During the course o this text, all ve stories will be investigated in detail. Tis section begins the investigation by analyzing two o these stories, both o which present surprisingly similar descriptions o huge sharks encountered of the coast o Australia. Te rst one is a truly amazing story; in act, it just may be the biggest sh story o all time.

T

cAsE #1: ThE LObsTErMEN’s TALE Tis 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 shermen (reerred to in the 24

One Whale of a Fih story

story as “craysh men”) who had an encounter with a huge sh while tending to their lobster traps (“craysh pots”). Te story goes as ollows: In the year 1918, I recorded the sensation that had been caused among the “outside” craysh men at Port Stephens, when, or several days, they reused to go to sea to their regular shing grounds in the vicinity o Broughton Island. Te men had been at work on the shing grounds—which lie in deep water—when an immense shark o almost unbelievable proportions put in an appearance, lifing pot afer pot containing many crayshes, and taking, as the men said, “pots, mooring lines and all.” Te craysh pots, it should be mentioned, were about 3 eet 6 inches [1 m] in diameter and requently contained rom two to three dozen good-sized craysh each weighing several pounds. Te men were all unanimous that this shark was something the like o which they had never dreamed o. In company with the local Fisheries Inspector I questioned many o the men very closely and they all agreed as to the gigantic stature o the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as an indication o the state o 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 o weather, and all sorts o sharks as well. One o the crew said the shark was “three hundred eet long at least”! Others said it was as long as the whar on which we stood—about 115 eet [35 m]! Tey armed that the water “boiled” over a large space when the sh swam past. Tey were all amiliar with whales, which they had ofen seen passing at sea, but this was a vast shark. Tey had seen its terrible head which was “at least as long as the roo on the whar shed at Nelson’s

25

26

MEGALODON: Fat o Fition?

Bay.” Impossible, o course! But these were prosaic and rather stolid men, not given to “sh stories” nor even to talking about their catches. Further, they knew that the person they were talking to (mysel) had heard all the sh stories years beore! One o the things that impressed me was that they all agreed as to the ghostly whitish color o the vast sh. 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 reused to return to their shing spot or several days. Stead believes the remarkable length o the shark reported by the lobstermen may be an unintentional exaggeration, resulting rom these normally unfappable men being so caught up in the spine-tingling excitement o the moment. He is convinced, however, that these lobstermen saw an immense shark unlike any they had seen beore. Tis is certainly one whale o a tale. Te act that great whites are known to attack lobster traps and buoys adds a measure o 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 Te ollowing 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 o Australia’s Great Barrier Ree, an 85 oot [26 m] ship experienced engine trouble which orced it to weigh anchor or repairs. Although the men subsequently reused to openly report what they had seen or ear o public

One Wale of a Fi stor

ridicule, the captain and his crew later told riends o sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long i not longer than their boat! Experienced men o the sea, they too were certain the creature was not a whale. Te antastic size and white color o this mysterious beast sound just like a slightly smaller version o the monster reported in the lobstermen’s tale. Perhaps the lobstermen’s description o their monster shark was accurate afer all. Ten again, it is necessary to consider the possibility that the crewmen in Case #2 were just abricating a copycat story. In either case, to evaluate both accounts it will help to determine the likelihood o Megalodon having the size and color described in these two stories.

M, Wat big Teet you have! I Little Red Riding Hood was impressed with the size o the Big Bad Wol’s teeth, she would have been abbergasted by the size o the teeth possessed by a Megalodon as big as the sharks described in Cases #1 and #2. Gottried’s shark-length ormula can be transormed into a tooth-length ormula by means o a little mathematical manipulation: front-tooth height (centimeters) = (length of Megalodon [meters] + 0.22) ÷ 0.96 Tis new version o the ormula can be used to calculate the size o the ront tooth o a Megalodon o any length. Plugging the lengths o the sharks described in Cases #1 and #2 into this ormula produces some pretty amazing results. Case #2 describes a shark at least 85 eet long. Since the ormula uses meters to measure shark length, the metric equivalent o 85 eet (26 m) must be plugged into the

27

28


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) Tus, a front tooth from a shark as long as the one described in Case #2 would have been almost 11 inches (28 cm) long. Tat 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.

One Whale of a Fih story

monster be? Te 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! Te 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. Te fact that this is not the case casts a shadow of doubt over both of these stories.

It’ a clear a blak 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 ooth’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. Te 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

29

30


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. Te 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

hark expert Michael Gottried’s Megalodon tooth ormula is a handy tool. By measuring the height o any ossilized ront tooth o a Megalodon, we can determine the body length o its owner. Te ormula is stated as ollows:

S

length of Megalodon, in meters = (0.96 x [front-tooth height, in centimeters]) – 0.22 For example, to determine the length o a shark whose ront tooth is 15 cm long, plug the tooth length into the ormula:

length of Megalodon = (0.96 x 15) – 0.22 = 14.4 – 0.22 = 14.2 m (or 46.5 feet) Tis ormula can also be rearranged to determine how large a ront tooth would be on a Megalodon o a specifc length. o do this, we simply rewrite the ormula.

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

One Whale of a Fih story

31

a seal or sea lion in the water, it sneaks up below or behind its prey and then lurches orward in a quick burst o power, catching its victim of guard and dealing a huge bite, causing the animal to quickly bleed to death. Te shark’s dorsal surace is colored dark gray, almost black, providing camoufage as the hunting sh blends in with the dark-colored sea bottom.

Since –0.22 + 0.22 = 0, the right side o the equation can be simplied, giving: length + 0.22 = (0.96 x [ ront-tooth height]) Now, divide both sides o the equation by 0.96: (length + 0.22) ÷ 0.96 = (0.96 x [ront-tooth height]) ÷ 0.96 Since 0.96 ÷ 0.96 = 1, the right side o the equation can be sim plied, giving: (length + 0.22) ÷ 0.96 = ront-tooth height Finally, fip-fop both sides o the equation: ront-tooth height = (length + 0.22) ÷ 0.96 Suppose you wanted to fgure how large a ront tooth should be on that 14.2-meter-long shark. Using this rearranged version o Gottried’s ormula, we get:

ront-tooth height, in centimeters = (length o megalodon, in meters + 0.22) ÷ 0.96 = (14.2 + 0.22) ÷ 0.96 = 15 cm By using this second orm o Gottried’s ormula, it’s easy to predict the size o the ront teeth o sharks such as the ones described in the lobstermen’s and crewmen’s tales.

32


Te great white shark is white on the bottom and dark on top for good reason. Te 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 fip side, the great white’s ventral surace is very light, almost pure white in color. When seen rom below, the shark’s belly blends in with the bright sky, again providing camoufage. Tis dark top/light bottom type o color pattern is known as countershading and is very common in shes. Although scientists cannot be absolutely certain about Megalodon’s colors without an actual specimen, they’re pretty condent that Mighty ooth, like its smaller, sealeating relative, had a dark top and a light belly, enabling it to sneak up on its prey.

One Wale of a Fi story

In that case, why would the eyewitnesses in Cases #1 and #2 declare that the monster sh was all white? Perhaps they were mistaken: Light reecting on the water’s surace may have played tricks on their eyes. Ten again, maybe this is urther evidence that both stories are just bs. Perhaps these ellows 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; i 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 or abricating such a antastic story? It could have been an alibi to cover up the accidental loss o their lobster traps. Maybe their marker buoy drifed away because it was not securely tied to the mooring line attached to the submerged traps. Without that buoy at the surace to mark the position o 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 goo-up by concocting a story about an encounter with a monster shark that had a sweet tooth or shellsh. 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 o the 1918 giant shark.” Furthermore, he points out that the story is “useless as evidence” or the existence o Megalodon, because Cartmell provides no reerences or anyone to double-check and veriy his story. In common language, this

33

34


Te oceans of Australia are prime hunting territory for many species of sharks living today. Te Great Barrier Reef on the northeastern coast is an especially popular hunting ground for sharks.

would be a case o hearsay evidence, o 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 o these events, especially since they both reportedly took place in the Pacic Ocean of the coast o Australia

One Whale of a Fih stoy

(the Great Barrier Ree extends all along the northeast coast o the continent, and Port Stephens is along the east coast, a bit north o the capital city o Sydney). For more than 40 years ollowing the 1918 incident, no one reported seeing any other huge, white monster sharks. Ten, at about the time the lobstermen’s tale was published in Stead’s book, the huge, white monster shark reappeared or a curtain call. Surely Stead’s sensational story would have caught the attention o Australia’s shermen and lobstermen. Te timing o these events denitely suggests the possibility that the crewmen in Case #2 simply read or heard about Stead’s story and decided to spin a tall tale o their own. On the other hand, the “act” that two white monster sharks were sighted in the same general area might suggest that a group o gigantic white Megalodons lived of the east coast o Australia. I that were the case, however, one would expect a gigantic tooth to be hauled up rom that region o the ocean oor rom time to time. But as pointed out earlier, no such teeth have ever suraced.

PrOGrEss rEPOrT #1: MEGALODON Considering the incredible sizes and unlikely coloration o the sharks described, the questionable circumstantial evidence surrounding the timing o the publication o Case #1 and the occurrence o Case #2, and the total lack o 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 or the modern-day existence o Mighty ooth. What about the other eyewitness accounts? Perhaps the stories o a amous author and his teenage son make a stronger case or the existence o Megalodon. It’s time to pull anchor, leave Australian waters, and set sail or the balmy open waters o the South Pacic.

35

3 Like Father, Like Son he next two eyewitness accounts o monstrous sharks have nothing in common with Cases #1 and #2, other than that they also occurred in the Pacifc 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 frst two accounts. Cases #3 and #4 suggest a totally dierent beast. Tis merits taking a closer look.

T

cAsE #3: ThE AuThOr’s TALE Zane Grey was the author o dozens o novels about cowboys and the Wild West. He was also an avid deep-sea angler who loved fshing or big-game fshes (marlins, swordfsh, and the like). Case #3 presents a brie account o Grey’s encounter with what some people think might have been a live Megalodon. 36

Like Father, Like son

While deep-sea shing in the South Pacic 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 ns and a ew white spots. . . . [It was] considerably longer than my boat—conservatively between 35 and 40 eet [10.5 and 12 m]. . . . I gured out that the sh . . . was not a harmless whale shark but one o the man-eating monsters o the South Pacic. Ten I was more rightened than I remember or 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 o these peaceul 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 or Grey’s “man-eating monster.”

One Whale of a shark As mentioned previously, the whale shark can grow to 50 eet (15 m) long, which is longer than the shark described by Grey. Tus, the size o Grey’s shark does not exclude the whale shark as a suspect. Neither does the shape o 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 o like a square with rounded corners), with a wide mouth at the ront. Te whale shark is a slow-poke flter eeder. It eeds by gaping its broad jaws wide open as it slowly swims at the surace. Tis allows water to enter the mouth and pass out through the gills, which are equipped with lterlike structures that trap small organisms drifing in the water. Grey describes the shark he saw as having a square head.

37

38


A whale shark is a slow swimming shark that feeds on algae and plankton. It is the largest of all the known sharks. Tis 20-foot (6-m) whale shark is feeding in the open water near Donsol, Philippines.

Grey mentions that his shark had huge pectoral fns. 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 o 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. Tey 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 surace. Tere are usually many white

Like Fate, Like son

or yellow spots and vertical stripes on the shark’s back, creating sort o a checkerboard pattern against the dark background color. Te number and pattern o spots varies, however, rom animal to animal: Some whale sharks have lots o spots, others have ewer. Te coloration o the shark Grey describes is not unlike what is known to occur in whale sharks. All o 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 n size, and the right coloration. I all this evidence isn’t enough to implicate the whale shark as t he sh that rightened Grey, Case #4, which also involves the amous 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 afer a deep-sea shing trip to the South Pacic island o ahiti. Tey were passengers aboard the steamer ship S.S. Maunganui. Loren, who was a teenager at the time, witnessed the ollowing scene as he gazed at a blotch o yellowish water visible rom the steamer’s deck: At rst I thought it was a whale, but when the great brown tail rose in the ship’s wake as the sh moved ponderously away rom the liner, I knew immediately that it was a monstrous shark. Te huge round head appeared to be at least 10 to 12 eet [3 to 3.7 m] across i not more. . . . It was my belie that this huge, yellowish, barnacled creature must have been at least 40 or 50 eet [12 or 15 m] long. He was not a whale shark: Te whale shark has a distinctive white

39

40

MEGALODON: Fact or Fiction?

purplish green appearance with large brown spots and much narrower head. So what was he—perhaps a true prehistoric monster o the deep? Here again, we have a description o a huge shark the size o 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 ather, however, Loren appears mistaken about the characteristics o whale sharks: Te “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 o inormation relating to Loren Grey’s story actually presents very strong evidence that his “prehistoric monster o the deep” was indeed a whale shark. According to shark expert Ben Roesch, the yellow patch o water seen near the shark was quite possibly a “cloud” o yellowish plankton (tiny organisms adri in the water) oating at the water’s surace. Such plankton clouds are known to attract hungry, lter-eeding whale sharks. Furthermore, the curious yellow color o Loren’s shark, as well as the “yellow and green” hue o his ather’s shark in Case #3, might be explained by yellowish plankton in the water. Te efect would be like gazing at the shark through a sheet o yellow cellophane. Are there any other living sharks that might be mistaken or the giant sharks observed by the Greys? Tere 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 o up to 33 eet (10 m). Tis is another bigheaded lter-eeder that slowly swims about at the ocean’s surace, mouth wide open, straining tiny organisms rom water that passes through its huge gills. Tis large, brown shark has a narrower head than the whale shark, immense gill slits that extend all the way down the sides o the head,

Like Fathe, Like son

Te basking shark, like the whale shark, is a flter eeder. It is the second largest shark in the world behind the whale shark. Te 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. Te sharks seen by Zane and Loren Grey were almost certainly whale sharks, not Megalodon.

41

42


Let’s Get Technical: Filter-Feeding Giants he largest o all sharks—whale sharks and basking sharks— eed on plankton, a mix o microscopic plants and animals, small sh, shrimplike crustaceans and other tiny invertebrates. How can such big animals survive by eating such tiny morsels o ood? By eating a load o them: One basking shark caught by scientists had 300 pounds (136 kg) o plankton in its stomach! Most o the ood energy in the ocean is stored in the countless billions o organisms that make up this plankton soup. In order to eed their tremendous bulk, whale sharks and basking sharks must strain thousands o gallons o seawater through built-in lters located in their gills. A eeding whale shark requently closes its huge mouth and orces seawater back through a sot, spongelike ltering material that collects plankton as the water fows through and out the gills. Tis spongy lter is supported by sturdy rods made o cartilage (the same substance that orms the sti part o your nose) so that it won’t collapse and let the plankton escape. Te basking shark doesn’t even bother to close its mouth when eeding; it just slowly swims orward, mouth wide open, letting the water fow through sti, bristly, plankton-trapping structures called  k. Te plankton eventually gets stuck in mucous at the back o 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 o leisure.

T

Tere’s still one case to go, a bizarre one to say the least. Case #5 is the story of an unusual shark attack. Te 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!

4 Things that Go Bump in the Night n the frst our cases that were investigated, the gigantic sharks apparently did not pay much attention to the eyewitnesses’ boats as they cruised by them. Tat is defnitely not the case in the fnal eyewitness account, which describes a close encounter o the toothy kind between a boat and a huge fsh—possibly a Megalodon.

I

cAsE #5: ThE cAPTAIN’s TALE Te ollowing story o 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

44


an interesting glimpse into the ascinating world o shark behavior: While in an Adelaide [an Australian port city] dry dock in March 1954, workers ound 17 teeth embedded in the ship’s wooden hull that reportedly resembled those o 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. Te teeth were arranged in a semi-circle (typical o a shark bite) about 2 m (6 f) in diameter, and the “bite” was near the propeller. Te propeller shaf itsel was bent. Te Rachel Cohen’s captain recalled a shudder the boat experienced one night during a storm near imor, Indonesia. At the time, he thought it had been caused by a collision with a oating tree trunk, which are apparently common in the area. Te events o 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 sh tale? Fortunately, this account provides some really useul details about the attack and denitely merits urther investigation.

boat hull and Propeller saft: Dinner, Anyone? It just so happens that many boats have been attacked by sharks. In almost every case, the perpetrator o the crime was none other than the great white. By studying the details o some o these unusual incidents, we can start to understand the mind o the white shark, and perhaps the mind o Megalodon as well.

Things that Go bump in the Night

45

Troughout history, sharks have been known to occasionally attack boats. Te perpetrator is most oten the great white. In this ctional illustration rom 1908, young girls in a boat ght of a pair o hungry sharks.

Tere 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 fsherman/writer Ernest Palmer’s description o the method o attack commonly used by boat-hunting white sharks: “[]he frst intimation o its presence is usually a violent thud upon the rudder, keel, or side o the boat and the propeller is requently mouthed and shaken by the shark, presumably to test whether the object is edible.” Palmer actually witnessed

46


such an attack on the propeller o the boat rom which he was fshing: “Te propeller struck the shark on the head three times but it continued to ollow until we anchored and caught the shark with three nasty gashes in the head.”

Let’s Get Technical: Shark Senses

H

umans rely on ve senses to learn about the world around them: sight, hearing, taste, smell, and touch. Sharks have all these senses, but they also have a ew others, which they use to monitor their environment in ways people can do only with the help o high-tech instruments. Sharks have a pair o eyes that are similar to human eyes. Located on the sides o the head, a shark’s eyes allow it to see in almost every direction. Tey are especially good at seeing in the dim light o dawn and dusk, and even at night, when many sharks are on the prowl. Tis “night vision” is possible because o the presence o a special structure in the back o the eye, the tapitum lucidum , which refects 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 o a fashlight. Sharks’ ears are located near the top o the skull. Even though the ears have no opening on the surace o the head, they are very good at detecting sounds such as those produced by injured animals fopping and splashing around in the water. Shark ears also have structures called semicircular canals , which help the sh maintain its balance as it moves through the water. Sharks have a keen sense o smell. Te nostrils, located near the tip o the snout, permit water to pass into sensory structures called nasal capsules , where biomolecules such as proteins (or 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 o prey miles away.


47

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 ood items as it bites or mouths them. Unusual items ound in the stomachs o sharks (or example, bottles and tin cans) are believed to have been accidentally swallowed while being tasted. Countless nerve cells o various types are located beneath a shark’s skin, providing the sh with a very sensitive sense o touch as well the ability to detect bending and stretching o the body as the shark swims through the water. Sharks also possess a lateral line , a network o pressure-sensitive nerve cells called neuromasts , located on the head and along the sides o the shark. By sensing changes in water pressure, the lateral line can detect moving objects. (o get some idea o 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 eel the pressure wave o water created by your swishing hand.) Finally, sharks possess an electrosense that can detect aint electrical elds produced by contracting muscle cells o other animals. Tese electrical elds are detected by a network o tiny structures, called ampullae of Lorenzini , located in the skin o the head and lower jaw. Tis sense is used or close-range snooping, as when scrounging around or prey buried under the surace o the sea foor. Te white shark is well-equipped to navigate through its watery world. Megalodon certainly was, too.

48

MEGALODON: Fat o Fition?

extremely weak electrical elds, such as those produced by the contraction o muscle cells in living organisms. Some sharks’ electrosense is so sensitive that they can detect prey that is buried under sand on the sea oor. It just so happens that the metal suraces o a boat’s propeller and propeller sha also produce a weak electrical eld in the water. It is believed that the white shark can detect these propeller-produced electrical elds; guring that the propeller is alive, the shark bites it to see whether it’s tasty. However, that’s not the whole story. Tere is evidence that white sharks don’t attack boats only when they are hungry. Tey may also attack i they eel their tur—or in this case, sur—is being invaded.

ONE’s cOMPANy, TWO’s A crOWD One o the most amous o all white shark attacks occurred in 1953, of the east coast o Canada. Tis incident is one o many shark attacks on boats described by shark expert Ralph S. Collier on the Web site o the Shark Research Committee: Commercial sherman John D. Burns, with companion John MacLeod, set out daily in his dory [a small shing boat] to harvest lobsters. Many dories dotted the sea in their quest o the prized crustacean, but only Burns’s had a white-painted hull. For nearly a week the white-hulled dory was ollowed by a large shark aer leaving the harbor. Day aer day the other shermen watched in disbelie as the shark stalked Burns and MacLeod’s dory rom behind, . . . No sooner would their dory put out to sea than a large dorsal n would appear astern o the boat. Ten, as the dory sailed alone on July 9, the shark charged, smashing an [8 inch, or] 20-cm hole through the bottom o the boat. . . . Te shark did not return aer its initial—and only—strike against the boat.


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 o eating it. Ten, when it discovered that the wooden hull was not particularly tasty, it swam of in search o 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. Te shark singled out Burns’s dory rom all the other shing boats. Perhaps this is because it was the only dory with a white hull. Recall that the lower surace o a white shark’s body is white. Tereore, it’s possible that the shark mistook the white-bottomed dory or another white shark, an unwelcome intruder. By ramming the dory, the shark may have been saying, in shark language, “Get out o here! Tis is my territory!” Tis interpretation o the shark’s behavior is not as crazy as it sounds, especially considering Collier’s account o another shark attack that occurred in 1989 along the Caliornia coast. In this encounter, a boat with a blue and white hull came upon a great white eeding on a harbor seal carcass. Upon the boat’s approach, the shark le 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 o times. By that point, the boat had dried away rom the seal. Te shark returned to its meal and resumed eating. Te tail-slapping behavior reported in this unusual incident provides an important clue as to the shark’s motive or 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 ood source, such as the dead harbor seal in the above account. As Klimley describes it, “Te behavior consisted o a shark liing the caudal n out o the water, pausing as i to direct it in a particular direction, and then rapidly

49

50

MEGALODON: Fat or Fition?

lowering it while contacting the water with considerable orce, oen splashing a large amount o water in the direction o another white shark.” wo sharks competing or a seal carcass slap water back and orth at each other until one shark, the one that makes the biggest splash, wins the contest—and the prize. ail slapping is a harmless way or white sharks to settle their diferences without ghting and injuring each other. Te 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 dried away as i in retreat, the shark gured it had won the “contest,” returned to the seal, and resumed eeding.

ANALyzING ThE EvIDENcE So how does all o 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. Tey bite boat hulls and propellers, either because they mistake them or ood, or because they mistake them or rivals. (Unortunately, this account does not provide enough inormation to determine the shark’s motive or attacking the cutter. Te incident occurred at night during stormy weather, so it’s not surprising that no one reported seeing any whale carcasses oating 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?

Tat’s One big Fis I the captain’s report is accurate, the teeth ound stuck in the cutter’s hull belonged to one big shark; we can use Gottried’s ormula to calculate just how big, assuming those 4-inch (10-cm) teeth were ront teeth:

Thing that Go bump in the Night

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 Te largest white shark ever caught was landed by fshermen in the Mediterranean Sea. It was 23 eet (7 m) long. Te shark described in Case #5 was substantially longer than that—8 eet (2.5 m) longer! I that shark wasn’t megalodon, it must have been one heck o a huge white shark! I those teeth were side teeth, then the ront teeth would have been even longer, meaning the shark itsel would have been even bigger, which fts with the reported 6-oot-wide (2 m) bite mark on the hull. (Recall that we previously noted that scientists fgured 6-oot-wide jaws would belong to a shark up to 50 eet [15 m] long.) I only someone had saved those teeth!

PrOGrEss rEPOrT #3: MEGALODON Te details presented in Case #5 are entirely in keeping with the known behavior o 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 o 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 fnd. A trophy, in act. Te lack o teeth as evidence casts a big shadow o doubt over the captain’s tale. As does the act that the sources or Roesch’s account provide no reerences that would allow anyone to double-check and veriy the story.

51

52


Why would the captain make up such a story? Perhaps to cover up the real cause o damage to the boat: Maybe the Rachel Cohen ran aground, smashing the propeller shaf against a submerged boulder or coral ree. Such a mistake might lead to disciplinary action by the captain’s superiors. In any case, we must ollow 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 o Megalodon, we must consider the very real possibility that this magnicent beast is extinct. Tereore, the next step in our investigation will be to try to gure out what could have led to this shark’s demise. o do this will require taking a giant step back in time, back to an era when megalodon still ruled the ocean.

5 A Long-Lost World harks have been around a long, long time. Some o the most ancient o all shark ossils belong to a little shark named Cladoselache, which cruised the ocean hundreds o millions o years ago. We know this because paleontologists have discovered numerous ossils o Cladoselache in 350 million- to 400 million-year-old sedimentary rocks, known as the Devonian Cleveland shales, located near the southern shores o Lake Erie. (“Devonian” is the name geologists— scientists who study rocks—have given to that portion o the geological time scale lasting rom 408 million years ago to 360 million years ago.) Tis shark was about 3 eet (1 m) long, and although it lived long beore the frst dinosaurs roamed the land, it looked pretty much like a typical modern-day shark. It had

S

53

54


Cladoselache

had a long, streamlined body and large tail that helped it swim fast. Te ancient shark is believed to have gone extinct approximately 350 million years ago.

a torpedo-shaped body, a mouth ull o sharp teeth, and the usual assortment o ns ound on modern sharks, including the tell-tale crescent-shaped caudal n typical o modernday speedsters such as the mako and the great white. Cladoselache is considered to be the granddaddy o all sharks, including Megalodon. In the vast expanse o time ollowing the reign o Cladoselache, sharks evolved into a multitude o species o diferent shapes and sizes. Yet, Cladoselache and most o its descendants shared one common eature: Tey 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 act, good-sized ossil sh have been ound in the stomachs

A Long-Lost Wold

o ossilized specimens o Cladoselache, proving that this little shark was indeed a very capable hunter.) Compared with Cladoselache, Megalodon is one o the newer kids on the block; the oldest ossil teeth o Carcharodon megalodon are only about 16 million years old. Yet, Megalodon—surely the ultimate marine predator and master o the underwater world—appears to have vanished of the ace o the Earth. Te youngest ossil Megalodon teeth discovered so ar are about 1.6 million years old. Aer that, the ossil trail vanishes. What could have caused the extinction o such a powerul predator?

A WOrLD OF chANGE It is a warm sunny day of the coast o what will become North Carolina in another 15 million years. A mother right whale, Mesoteras, has just calved and nudges her young to the surace to draw in its rst breath o air. Suddenly a large dorsal and caudal n o a Carcharodon megalodon breaks the surace o the water and the young cal disappears within seconds in a swirl o red water. Swallowed whole by a 17 meter giant [Megalodon] shark, the Mesoteras cal dies in a scene reminiscent today o adult Great White Sharks eeding on seals of Caliornia and Australia. Tis bloody scene, described by paleontologist John Clay Bruner, portrays what was probably a common event in the ancient seas inhabited by Megalodon. Fieen million years ago, however, Earth’s oceans were quite a bit diferent rom the way they are today. By looking at these diferences, we may nd clues that provide an explanation or the extinction o Mighty ooth.

55

56


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

he Earth has been around a long time: 4.5 billion years. o 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). Tis scale divides Earth’s history into shorter, more manageable blocks o time. Te geological time scale allows geologists to label portions o Earth history in much the same way that taxonomists use their classication system to label organisms. Instead o talking about kingdoms, amilies, and species, however, geologists talk about eras , periods , and epochs . For example, the shark Cladoselache lived during the Devonian Period, which extended rom 408 million years ago to 360 million years ago. Megalodon rst appeared in the Miocene Epoch, which lasted rom 23.7 million years ago to 5.3 million years ago. Te boundaries o the diferent divisions o the geological time scale represent sudden changes in the types o ossils contained in successive layers o sedimentary rock. (Te actual age o these boundaries can be determined by measuring the relative amounts o radioactive elements, such as uranium, contained within the rock layers.) Tese sudden changes in the ossil record oten signiy major environmental catastrophes that caused the sudden extinction o many diferent orms o lie. Te most amous such mass extinction occurred 65 million years ago, when it is believed that an asteroid smashed into Earth and wiped out the dinosaurs. Tis catastrophe marks the boundary between the Mesozoic and Cenozoic Eras. Older rock layers are harder to date accurately than younger ones. Also, the ossil record in older layers is more patchy and incom-

T

A Long-Lost World

57

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.

e geological time scale divides and subdivides the 4.5 billion years of Earth’s history into smaller and smaller units of time.

58


than it is today. Much land that now lies above sea level actually ormed the bottom o shallow Miocene seas covering thousands o square miles. One such sea covered a huge portion o the southeastern coast o the United States. One o the world’s best sources o megalodon teeth is sedimentary rocks rom states such as North and South Carolina. Tese rocks ormed rom mud and other materials (along with shark teeth) that settled on the surace o the shallow Miocene seabed. Scientists don’t think that this is a coincidence. Tey believe that the large number o shark teeth ound in these rocks indicates that Megalodon liked to hang out in these warm, shallow seas. Why? Recall that ossil whale bones have been ound along with those ossil shark teeth. Apparently, Miocene whales also liked to hang out in these warm, shallow waters. Observations o modern whales suggest why this was the case. Many kinds o whale give birth in warm, shallow water near the shore. For example, emale gray whales (Eschrichtius robustus) migrate thousands o miles rom rich eeding grounds in icy arctic seas in order to give birth in warm, shallow lagoons along the Pacifc coast o Caliornia. Tey do this because baby whales, called calves, have very little o the atty, insulating blubber that protects adult whales rom the cold water o their rigid eeding grounds. I calves were born in that icy water, they would quickly die rom 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 o blubber as they slowly migrate north to arctic eeding grounds. So i baby whales were present in these warm seas, it’s reasonable to fgure that hungry Megalodons would have been present, too. By studying the predatory behavior o another whalehunter, namely humans, we can uncover another possible reason why Megalodons haunted these shallow seas. Back

A Long-Lost World

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. Tis was much safer than dealing with an angry mother whale in the open ocean, where she could maneu ver easily, possibly ramming t he whalers’ boat or smashing it with her tail.

Tere have been numerous ice ages in the history of Earth. Te 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.

59

60


Perhaps Mighty ooth was smart enough to realize that mother whales were less maneuverable in shallow water, making shallow-water hunting o calves a saer proposition. Aer all, there’s no sense risking being slammed by an enraged mother whale i it’s not necessary. Te 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 emales o Mighty ooth’s close relative, the great white shark, give birth in shallow water, scientists believe that Megalodon might have done the same. (While many species o shark lay eggs, some, including the great white, bear live young. White shark newborns are 4-oot-long [1.2 m] miniature versions o their parents. Scientists gure that baby Megalodons would have been about 12 eet [3.5 m] long.) I that was the case, then shallow Miocene seas would have served as both dining room and nursery or the huge shark. No wonder so many ossil teeth have been ound in the southeastern United States! Approximately 3 million years ago, toward the end o the Pliocene Epoch, Earth’s climate took a turn. emperatures worldwide cooled of, 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 o ice covered thousands o square miles o land in North America, Greenland, Europe, and Asia. Te Ice Age had arrived.

The Triple Whammy During the peak o the Ice Age, during the Pleistocene Epoch, so much water was locked up in the huge northern glaciers— towering sheets o ice up to 1.2 miles (2 km) thick—that the sea level dropped more than 330 eet (100 m), completely

A Long-Lost World

A group of four killer whales surround their prey—a gray whale mother and calf. Te 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. Tere 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. Tis 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 ooth for the title of op Predator of the Seven Seas? None other than Orcinus orca: Orca, the killer whale.

61

62


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

harks lose a lot o teeth. It’s not uncommon or a shark to lose one or more teeth when eeding, especially when the prey has thick or tough skin. A lost tooth, however, is no big deal to a shark. Sharks have several rows o teeth, although only those in the ront row are used or biting. Te teeth in the other rows are replacements. I a ront-row tooth gets yanked out by a struggling seal—or boat hull—the tooth behind it in the second row moves orward to replace it. Sharks have lost so many teeth over the eons that ossilized shark teeth are among the most common o all ossils. A ossil Megalodon tooth consists o several parts. Te relatively sot, spongy center o the tooth is the pulp. (In live sharks, the pulp contains tiny blood vessels and nerve cells.) Te pulp is surrounded by a relatively thick layer o a strong, hard substance called dentine . Te dentine layer is covered by a thin layer o enamel , a material that is extremely brittle and hard—harder even than bone. Te enamel is glued to the underlying dentine by a substance called cementum . Te bottom o the tooth, the root , attaches to the jaw. Along the side o the tooth, where the root meets the upper part o 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 foor 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 o

S

A Long-Lost World

63

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. o say orcas are smart may be an understatement. Tese largest members of the dolphin family employ an amazing variety of hunting

the tooth. Te increasing weight o this ever-deepening layer o 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 rom creamy peach or yellow to rusty red, brown, or even black. Only reshly shed shark teeth are white; ossil teeth are always discolored. Tis 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 fourishing somewhere in the vastness o the oceans and has simply lost a tooth.” Tis entire ossilization process can take up to 100,000 years to complete. Eventually, perhaps millions o years later, sedimentary rock containing a trapped ossil shark tooth may be brought to the earth’s surace during mountain-building processes and/or earthquakes, where the rock is weathered by wind and water until the ossil is exposed and, ultimately, detected by the watchul eye o a ossil-hunting cryptozoologist.

64


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 o the sea.” When hunting schools o sh or pods o their smaller dolphin cousins, orcas surround their prey, herd them into a tight circle to cut of escape, and then go in or the kill. Pinnipeds are among the killer whale’s avorite oods. Seals and sea lions sometimes have the opportunity to employ an escape strategy unavailable to sh and dolphins: Tey can haul out onto land or, in rigid climates, oating chunks o sea ice called ice ras. (In such a situation, “lie ra” might be a more appropriate term.) Yet, orcas have ound several ways to get around this seemingly ool-proo escape strategy. When a seal seeks reuge on an ice ra, a hunting killer whale may splash waves o 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 o the water and onto the ice, knocking the seal back into the water. Or it may ram the ice ra rom below, tipping it up and causing the seal to slide into the water. I an orca spots a seal on land close to shore, it may actually launch itsel onto the beach and slide on its belly right up to its terried target, grab its meal, and then make its way back into the water. When a pod o orcas attacks large prey, such as a big whale, the orcas will surround their quarry , boxing it in rom all directions, and then take turns, tag-team style, biting chunks o esh rom their helpless victim. Tis type o assault is very efective against whales much larger than orcas. Scientists aboard a Sea World research ship once witnessed such an attack on a 60-oot-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 o

A Long-Lost World

the shark’s dangerous mouth. Tey might also have subdued the giant shark by smashing into it battering ram-style, aiming or the gills or other vulnerable areas. A newborn Megalodon, even though 12 eet (3.5 m) long, would have been a sitting duck or even a lone hungry orca. In act, humans have witnessed what could be considered a reenactment o an attack by an orca on a young Megalodon. In 1997, Peter Pyle, a Point Reyes Bird Observatory biologist stationed at the Farallon Islands of the coast o Caliornia, was notied by the captain o 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 o two orcas dragging the carcass o a 10-13 oot (3-4 m) white shark—the exact size o a newborn Megalodon—along the surace o the water. A ew minutes later, the shark’s liver squirted out o its tattered body, whereupon the orca released the carcass and gulped down the liver. What remained o the dead shark slowly sank out o sight. Pyle and his colleague Alisa Schulman-Janiger put the pieces together and determined the probable sequence o events that led to the white shark’s demise: A dead sea lion seen oating at the surace (the Farallon Islands are amous or their huge pinniped rookeries) had probably just been killed by one o the orcas. Te hungry shark smelled the sea lion’s blood in the water and came over to investigate, whereupon one o 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. Te waters around the Farallon Islands are normally a popular hunting ground or great whites rom September through December, when elephant seals gather at the rookeries to breed. During these months, dozens o the big sharks normally patrol the nearshore waters, looking or ood. As soon as the orca killed the inquisitive shark, however, the other white sharks quickly

65

66


vanished rom the area. Tey apparently smelled the tattered remains o the dead shark and decided to leave their hunting grounds beore they ended up as the orca’s dessert. Tree years later, a similar incident occurred at the Farallones. A male white shark named ipn—so named by researchers studying white shark migration—presented an interesting tale. Te researchers had attached an electronic “pop-up” tag on ipn’s back in order to record the temperature and depth o the water in which he was swimming. Te pop-up tag recorded temperature and depth every two minutes or six months and then popped up to the surace (hence its name) and transmitted its recordings to the researchers via satellite. When the scientists studied ipn’s depth data, they were surprised to nd out that at almost the exact time that witnesses had spotted a huge sh—probably a white shark—that had just been killed by a killer whale, ipn descended rom the surace to a depth o 1,640 eet (500 m) and hightailed it away rom the islands. Clearly, orcas and white sharks do not get along. Tey 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 o today’s killer whales were also erce competitors or the same reasons. Unortunately, when two species compete or ood or other critical resources, one species ofen survives at the expense o the other, which eventually goes extinct. We know that the ancient orcas sur vived; Shamu and Namu are proo o that. We can’t say the same or Mighty ooth. As i orcas weren’t enough o a problem or Megalodon, the ossil record shows that many o the whale species that Megalodon probably preyed upon disappeared during the Ice Age cool-down. Tis disappearance probably took place because the whales’ own ood (sh, squid, plankton, and more) could not survive in the colder climate.

A Long-Lost World

With all these things happening at the same time, it’s hard to determine just what brought about the extinction o Megalodon. Most scientists believe that no single actor was responsible or knocking of the giant shark. Many ichthyologists believe that the efects o the Ice Age, competition rom orcas, and the disappearance o Megalodon’s preerred prey combined to produce a triple whammy that was just too much or the shark to handle. In any event, by the middle o the Pleistocene, Carcharodon megalodon was gone. (As mentioned previously, the youngest Megalodon teeth ound so ar 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 ound are actually ossils? Tat’s easy. Recently shed shark teeth are always white, whereas ossil teeth are discolored, anything rom 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 ound. Despite this act, some people reuse to give up hoping that Megalodon still survives somewhere in the vast depths o the world’s oceans. Is this just wishul thinking, or do these people have good reason to believe that Mighty ooth might still exist? As the next section shows, the ocean is ull o surprises, some o which would equal the discovery o a living Megalodon, even a ghostly white one.

67

6 Mysteries From the Deep Blue Sea  you have seen the 1993 movie Jurassic Park, you may remember the dropped-jaw look o utter amazement on Dr. Grant’s ace when he encounters his rst live dinosaur. Speechless and weak in the knees, he crumples to the ground, hardly able to believe what he is seeing. Afer all, the last o 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 ction, 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 or millions o years couldn’t have survived undetected, leaving no trace—

I

68

Myter ie From the Deep blue sea

Once thought to be extinct, a coelacanth was discovered discovered in the ocean of the coast o South S outh Arica in 1938. Since then, other living specimens have been ound, but their sightings are rare, and the sh is classied as an endanger endangered ed species. Coelacanths are deep-sea creatures that live at depths o up to 2,300 eet (700 m).

not even a single ossil—and then suddenly reappeared, reappeared, alive a live and well, beore the amazed eyes o the scientic world? As it turns out, something like this actually did happen a number o years ago: An animal that was thought to have gone extinct even beore the dinosaurs met their end was ound alive and living in—you guessed it!—the deep, dark depths o the ocean. Just what kind o animal pulled of this amazing disappearing act? A sh. Mind Mi nd you, this was no teeny, teeny, tiny ti ny guppyguppyo-a-sh that could easily be overlooked in the vast expanse

69

70

MEGALODON: Fat o Fit ion?

o the ocean. Tis 5-oot-long (1.5 m), 127-pound (58 kg) lunker, known as a coelacanth (SEE-luh-kanth), was almost as big as the scientist who identied it. It had a big, toothy mouth, huge armorlike scales, and stubby, lobe-shaped ns. Te ossil record o lobe-nned shes petered out during the Cretaceous Period, Period, about 80 million mi llion years ago, which is why the discovery o a living coelacanth was so astonishing. It’s worth taking a close look at this unusual sh story, because people who believe Megalodon may still exist eel that the story o the coelacanth supports their stance. I this lobe-nned sh could could survive surv ive unknown and undetected into modern times, perhap perhapss Megalodon could do the same. sa me. ThE cOELAcANTh’s cOELAcANTh’s sTOry Te year was 1938, ve years afer Loren Grey’s encounter with his “prehistoric monster o the deep” in Case #4. Upon returning to the port town o East London, along the east coast o the nation o South Arica, Hendrick Goosen, captain o the shing boat Nerine, relayed a message to Marjorie Mar jorie Courtenay-Latimer, CourtenayLatimer, the curator o the t he East London Museum. He invited her to come down to the dock to examine the shes that his crew had just caught in their trawling net. (A trawling net is a huge sh net that is dragged along the bottom o the ocean.) He told Courtenay-Latimer she could buy any o the shes that she wanted or the museum’s sh collection. Along with the usual assortment o sharks, cod, and other deep-water deep-water shes was an a n unusual one that CourtenayLatimer had never seen beor beore. e. It was a large purplish-blue purplish-blue sh with shiny, silvery spots and unusual, lobe-shaped ns. She bought the sh and brought it back to the museum. Unable to identiy it, she sent a description o the weird sh to James L.B. Smith, a teacher at Rhodes University University in Grahamstown, Gra hamstown, some 50 miles (80 km) south o East London. Smith, who taught chemistry at the university, was also a sh expert.


Afer researching the inormation provided by CourtenayLatimer, Smith concluded that she was describing a crossopterygian, or lobe-n. Many scientists believed this sh might have been the ancestor o amphibians, the rst vertebrates (animals with backbones) to crawl out o the water and onto the land. According to the ossil record, crossopterygians rst appeared during the Devonian Period, just like the ancient shark, Cladoselache. Unlike sharks, however, lobe-ns were thought to have become extinct. o discover a living lobe-n would be the scientic nd o the century! By the time a very excited Smith arrived in East London, Courtenay-Latimer’s sh had started to decompose, and the internal organs had been removed and discarded. Nevertheless, when Smith nally gazed upon the remains o the sh, 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 ime: Te Search for the Coelacanth, Smith was obviously thunderstruck by what he saw. “Although I had come prepared, that rst sight hit me like a white-hot blast and made me eel shaky and queer, my body tingled,” he said. “I stood as i stricken to stone. Yes, there was not a shadow o doubt, scale by scale, bone by bone, n by n, it was a true Coelacanth.” In a newspaper article that he later wrote about his encounter with the coelacanth, Smith included a bit o advice or his ellow scientists: “We have in the past assumed that we have mastery not only o the land but o the sea. We have not. Lie goes on there just as it did rom the beginning. Man’s inuence is as yet but a passing shadow. Tis discovery means that we may nd other shlike creatures supposedly extinct still living in the sea.” Some people believe that Megalodon might be one such creature. Te coelacanth isn’t the only amazing, totally surprising sh to come to ichthyologists’ attention in the past 70 years. In 1976, a remarkable creature was accidentally caught in the anchor o a U.S. Navy boat. Tis was no tiny guppy-o-a-sh,

71

72


either. Appropriately either. Appropriately enough, this sh was actual ac tually ly a shark shark— — a big shark. MEET MEGAM MEGAMOuTh OuTh In 1976, crewmen aboard the AFB-14, a Navy research vessel, were in or a real surprise when they hauled in the boat’s 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.) Tey discovered that one o the sea anchors, which had been driing dri ing at a depth dept h o 500 eet (152 (152 m) m) of the t he shore o Hawaii, had been swallowed by a huge shark with a large, seemingly oversized head. Te shark was more than 14 eet (4.3 m) long and weighed more than 1,500 pounds (680 kg). Its mouth was studded with thousands o tiny ti ny teeth and surrounded by thick, eshy lips.

Let’s Get Technical: Coelacanths

coelacanth is a “living ossil.” Te modern-day coelacanth (its scientifc name is Latimeria chalumnae) looks almost identical to its ossilized ancestors that lived hundreds o millions o years ago, during the Devonian Period. Its crossopterygian relatives gradually evolved into the frst amphibians, some o which eventually evolved into the frst reptiles, some o which in turn evolved into the frst mammals (the whole process taking a couple hundred million years). Te coelacanth itsel, however, stayed pretty much just the way it was, a creature obviously very well suited to living the lie o a coelacanth. Coelacanths spend the daylight hours resting in caves hundreds o eet beneath the surace. Tey are nocturnal hunters, leaving the protection o their caves by night and swimming up into shallower water. Tere, their large eyes help them fnd their fsh prey in the dimly lit water. Coelacanths eat a wide variety o fshes, including

A


73

Appropriately dubbed “megamouth” because o its huge mouth, mou th, this t his previously unknown sh turned tur ned out to be another another lter-eeding shark. In act, scientists eventually classied it as a distant relative o the much larger lter-eeding basking shark and gave it the name Megachasma name Megachasma pelagios, pelagios, meaning “big mouth rom deep water.” Several more megamouth megamouth sharks shark s have been caught in the years since the anchor-eater was caught in 1976. In 1984, a 15-ooter (4.6 (4.6 m) was caught c aught at a depth dept h o 125 eet (38 m) m) in a sherman’s net of the coast o Caliornia, near Los Angeles. Others have since been ound ound near Japan and Australia. Austra lia. Scientists believe that megamouth is a deep-water ltereeder, which would explain why it avoided detection or so long. By spending most o its time in the depths, it would have avoided detection by people in boats at the surace. Since it eats plankton and a nd other small critters, cr itters, it wouldn’t wouldn’t be

eels, rays, and small sharks, which they snatch up with their large, powerul mouths. Tese primitive-looking animals are obviously very capable hunters. Not surprisingly, fshermen o the Comoros Islands usually catch coelacanths on their fshing lines at night, when the coelacanths are out and about searching or prey. Te secretive nature o the coelacanth explains why it remained undiscovered by scientists or so long. I it hadn’t been or Marjorie Courtenay-Latimer’s lucky discovery o that frst coelacanth among all the other ordinary fshes hauled in by the trawler Nerine , we might still be unaware that coelacanths have survived into modern times. Tis is why some people believe that Megalodon may still be around: It may be living a secretive way o lie as well, out o the view o humans—although, humans—although, quite rankly, it’s it ’s hard to imagine how 45-oot 45-oot-long (14 (14 m), whale-eating sharks could go unnoticed or long!

74


Tis stufed megamouth shark was caught in August 2003 in the Pacic Ocean. Tis one-o-a-kind stufed stufed sh was on display at a Japanese museum where curious kids could get an up-close look.

tempted to latch onto large baitfsh on a hook the way other open-water predatory fsh (such as other sharks, marlin, and swordfsh) would. Such a liestyle is in stark contrast to that o Megalodon, the streamlined, speedy, shallow-water, whale-slaughtering whale-slaugh tering machine which could hardly be expected to remain hidden rom view or very long. As i in response to those who believe that Mighty Tooth Tooth still sti ll survives, sur vives, author Richard Ellis points out in Great White Shark that a number o megamouths have now been observed, but so ar not a single live Megalodon has been sighted. I Megalodon did


still exist, one would expect it to be encountered at least as requently as the secretive megamouth.

DEEP-DIvING? Recent research by ichthyologists has revealed some surprising inormation about the migratory habits o Megalodon’s little cousin, the great white shark. For years, most ichthyologists had assumed that white sharks spent almost all o their time moving back and orth between eeding and breeding grounds located in shallow coastal waters, particularly around Australia, South Arica, and the east and west coasts o North America. Tey now know that this is not the case. In the 2000 study in which scientists made the acquaintance o ipn (the male white shark mentioned earlier), ichthyologist Barbara Block o the una Research and Conservation Center, Peter Pyle, and several colleagues attached pop-up tags to ipn and ve other white sharks. Te 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 eet (27 m). What surprised the scientists was what happened aer the seals dispersed at the end o breeding season: Most o the tagged sharks headed ofshore into the deeper waters o the Pacic Ocean. wo o the sharks stayed near the Farallones, but three o the sharks swam to open water several hundred miles to the southwest, and ipn, ollowing 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 ollowing November, at the peak o the elephant seal breeding season. Te researchers discovered that the tagged white sharks spent up to ve months o the year swimming in the deep waters o the open ocean, oen swimming at a depth o

75

76


approximately 1,000 eet (305 m). Why did those sharks travel such long distances in the open ocean? No one knows or sure. According to Burney Le Boeu, one o the researchers involved in the study, “What they were doing out there is a mystery. Since they were hunting or seals when tagged, such a long migration suggests a possible rendezvous or mating, or a move to eed on diferent prey.” As impressive as ipn’s journey to and rom Hawaii was, it pales in comparison to the record-setting voyage undertaken by Nicole, a emale white shark tagged in the shallow waters near pinniped rookeries of the coast o South Arica. Nicole was one o 32 white sharks tagged in November o 2003 by scientists rom the Marine and Coastal Management Department o South Arica. While the sharks commonly migrated up and down the east coast o South Arica, 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 oen swam at the incredible depth o more than 3,200 eet (976 m). Nicole’s pop-up tag detached and oated to the surace while she was in Australian waters, but scientists know that she returned to South Arican waters the next summer: Tey spotted her uniquely marked dorsal n—identical to photos taken the year beore—slicing through the waves along the South Arican coast in August o 2004. Te results o these studies o white shark migration might encourage people to believe that Megalodon still exists. Aer all, i ipn, Nicole, and other white sharks have been ound to spend a lot o time hidden rom view in the deep water o the open ocean, who is to say that Megalodon doesn’t do the same? Te truth o 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

Myte ie Fom te Deep blue sea

come up empty. Still, Ellis’s reasoning is hard to argue with: I Megalodon were still around, we should have seen it—or at least some o its huge, white teeth—by now.

LOrD OF ThE DEEP One other point needs to be presented beore we close the book on Megalodon. Recall rom the preace that the rst step in any cryptozoological investigation involves gathering as much inormation about the cryptid as possible. O particular value is inormation provided by people who live where the cryptid hangs out. Te story o 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-n was not unknown to natives o the Comoros Islands, located of the east coast o Arica. Fishermen rom the Comoros occasionally catch coelacanths on their shing lines. Tey even have a name or the lobe-n: gombessa. Tis example is proo positive that native people o so-called “primitive” cultures are likely to know more about the natural world that they work and live in than do highly educated scientists o modern, “advanced” cultures rom other parts o the world. Te coelacanth isn’t the only animal discovered by scientists long aer it became known to local inhabitants. Many animals now commonly seen running, swimming, or ying in zoos, on the pages o nature magazines, and on V documentaries were known to native cultures or countless generations prior to their discovery by scientists and explorers rom Europe and elsewhere. Examples include the white-backed tapir rom India, a distant relative o the rhinoceros, “discovered” in 1816; the Arican pygmy hippo in 1849; China’s giant panda in 1869; and the mountain gorilla, the largest o all the apes, in 1903. By noting instances such as these, it is obvious why cryptozoologists begin their cryptid quests by gathering as much

77

78


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).


inormation as possible rom people who are neighbors o their quarry. What does all this have to do with Megalodon? It just so happens that native shermen o some islands in the South Pacic believe in the existence o a 100-oot-long (30 m) sharklike creature that they call the Lord o the Deep. It’s a traditional belie that goes back many generations. As unbelievable as such a beast would appear to modern science, one can’t help but wonder i there is more than just a grain o truth behind this belie. It might also make one wonder whether some o those cases we’ve explored are not quite so ar-etched afer all. Te stories related by Zane and Loren Grey appear to be cases o mistaken identity. But what about the lobstermen’s, crewmen’s, and captain’s tales? Even though the evidence—or lack thereo—casts a cloud o doubt and suspicion over the truth and accuracy o these accounts, they can’t be ruled out with absolute certainty. Afer all, we weren’t there to witness what, i anything, actually happened. Even though it’s a long shot, maybe, just maybe, these suspicious-sounding stories are based on actual sightings o that mysterious creature known in some places as the Lord o the Deep. Te point is, we shouldn’t be totally surprised i, someday, the ront pages o newspapers throughout the world scream out with the headline “Cryptozoologist Captures ‘Lord o the Deep’ ”. Such a headline would be accompanied by a photo o 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 beore. Tey will probably happen again.

79

7 Final Report: Megalodon ll the Megalodon data has been collected and analyzed, and a brie summary o our ndings is now in order. Te lobstermen’s tale (Case #1) describes an incredibly huge (between 115- and 300-oot-long, or 35- and 91-m-long), white shark with a taste or lobster. Studies o the great white shark, megalodon’s closest living relative, suggest that Mighty ooth might indeed make a meal o the lobstermen’s catch, even though marine mammals, especially whales, are probably this shark’s preerred prey. So this part o the account is believable. Te all-white coloration claimed or this sh, however, fies in the ace o what scientists know about sh color patterns. Countershading is the rule, rather than the exception, or stealthy predators such as the great white and, presumably, or Megalodon. A monstrously huge, all-white

A

80

Final repot: Megalodon

shark would have an awully hard time sneaking up on intelligent, sharp-eyed, whales. Finally, by using Gottried’s ormula, the ront teeth o a shark the size reported in this case were calculated to be up to 3 eet (91 cm) long. Since the largest o the hundreds o Megalodon teeth that have been ound 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. Te problem with the shark’s color and size, combined with a possible nancial motive to make up such a wild story to explain the costly loss o the ship owner’s lobster traps, makes the lobstermen’s tale a poor source o evidence justiying belie in the modern-day existence o Megalodon. Te crewmen’s tale (Case #2) does not are any better under careul analysis, and or pretty much the same reasons. Te white color and the incredible size claimed or the sh in this account make or a story as hard to believe as Case #1. Although there does not appear to be a monetary motive or making up this tale, the coincidence in the timing o the telling o this story and the publication o Case #1 in David Stead’s Sharks and Rays of Australian Seas suggests that the crewmen’s tale is simply a copycat hoax. Te author’s and teenager’s tales (Cases #3 and #4, respectively) are both clear-cut cases o mistaken identity. Comparative studies o the teeth o Megalodon and the great white shark indicate that Megalodon looked like a supersized, beey version o the great white. Te accounts by Zane Grey and his son Loren o the huge sharks they encountered on their South Pacic shing excursions describe sharks that look very much like whale sharks, which look very diferent rom great whites. Furthermore, Loren’s mention o a blotch o yellow water near the shark he saw is the real clincher. Tat yellow smudge was almost certainly a cloud o plankton, the whale shark’s preerred ood.

81

82


Troughout history, people have been captivated by the thought o a giant shark that stalks the seas, such as the erocious creature in the blockbuster flm Jaws. In this photo, two children play with the amous lead character at Universal Studios, Florida.


Te 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-oot-wide mouth. Tat mouth size is appropriate or a shark the size o a large Megalodon, and the reported attack on the cutter’s propeller is entirely consistent with the known behavior o Mighty ooth’s little cousin, the great white. No one, however, appears to have saved any o the extremely valuable 4-inch-long teeth that were reportedly ound stuck in the cutter’s hull. In addition, the source or the story provided no reerences that could be checked or accuracy and honesty. Tereore, the whole story is unortunately just that: a story . . . and nothing more. o sum things up, we’ve analyzed all ve eyewitness accounts o possible Megalodon sightings. Tree o the accounts (Cases #1, #2, and #5) are unveriable at best and hoaxes at worst, and two (Cases #3 and #4) are obvious cases o 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. Te evidence obtained rom all ve cases is strictly hearsay, and while some o it agrees with what scientists know about shark behavior (or example, attacks on lobster traps and boats), some o it conicts with known acts about shark size and coloration. Tere is no way the inormation extracted rom these ve cases can override two important acts: rst, no actual specimen o Megalodon, dead or alive, has ever been ound; and second, all o the Megalodon teeth ound to date are ossils no less than 1.5 million years old. On top o that, scientists have come up with a very convincing explanation or Megalodon’s probable demise: the triple whammy efect o the Ice age (which resulted in cooler water temperatures and the disappearance o shallow seas), the

83

84


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. Te jaw was part of a collection of prehistoric fossils, but the costly fossil did not sell that day.

disappearance o the shark’s avorite whale prey, and erce competition rom the ancestors o the killer whale. Afer taking all the above ndings into consideration, we must conclude that there is no reason to believe Megalodon still exists—except in hopeul imaginations. Still, the stories o megamouth and the coelacanth show that the ocean is


85

teeth depend on their size, color, and condition, and can range rom $10 or a 1.5-inch (3.8-cm) weathered, chipped, and/or cracked specimen, to $7,000 or a 6-inch (15-cm) tooth in pristine condition— having nice, sharp serrations along the edges, and ew i any cracks or chips in the enamel. Te enamel in the most valuable specimens has beautiul color patterns that rival those seen in fne jewelry and gemstones. In act, some dealers polish little Megalodon teeth and mount them as shimmering pendants in unique, eye-catching necklaces. Fossil dealers usually sell their Megalodon ossils one tooth or necklace at a time, but there are exceptions. In April 2009, the worldamous auction house Christie’s conducted its third annual Natural History exhibit and auction in its Paris gallery. Displayed alongside spectacular ossilized skeletons o an ichthyosaur (an extinct marine reptile) and other prehistoric animals were the amazingly lielike reconstructed jaws o a large Megalodon. (Reconstructed Megalodon jaws are models made o fberglass.) Adorned with 168 ossil teeth, the huge, wide-open jaws stood 7.2 eet (2.2 m) tall and had an estimated value o well over $200,000. Although Christie’s sold the ichthyosaur skeleton or an impressive $242,652, no one bought the Megalodon jaws; those pricey teeth apparently threatened to take too big a bite out o ossil 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?

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 Anal fin 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. Biomolecule A molecule produced by a living organism (for example, hemoglobin, the oxygen-carrying molecule in blood cells) 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 Camouflage A disguise that helps an animal blend in with its surroundings in order to avoid detection Caudal fin The tail fin of a fish that is used to propel the fish through the water 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 organisms; a class is composed of closely related taxonomic orders, and closely related classes are in turn grouped together into a phylum. Cloaca A chamber or cavity beneath the ventral surface of a shark’s body (also found in other fishes, amphibians, and 86

Glossary

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 Dorsal fin 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. 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

87

88

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 organisms; 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. Genus (plural: genera) 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. Geological time scale 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. Gill A feathery-looking respiratory (breathing) organ that extracts life-giving oxygen from the water Gill raker A stiff, comblike structure in a gill that strains small food organisms from water as it passes through the gills Gill slit 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 Ichthyologist

A scientist who studies fishes

Invertebrate An animal without a backbone (for example, worms, insects, and crustaceans) Kingdom One of the levels of taxonomic classification of organisms; a kingdom is composed of closely related phyla. 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.

Glossary

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. Mooring line A rope that connects an object on the sea floor, such as a lobster trap, to a marker buoy floating on the surface above Nasal capsule A tiny chamber connected to a shark’s nostril that contains sensory cells that can detect biomolecules, such as blood, in the water Neuromast A pressure-sensitive nerve cell found in the lateral line system Order One of the levels of taxonomic classification of organisms; 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 Pelvic fin 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. 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. Phylum (plural: phyla) 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.

89

90

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 Rendezvous Retina

Made over or rebuilt to look like the original

A meeting place

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. Root The portion of a tooth that is beneath the blade and attached to the jaw Sedimentary rock A rock formed by the settling and compacting of soil particles, stones, mud, and silt on the bottom of rivers, lakes, and oceans Semicircular canal A structure in the ear that helps an animal to maintain balance and coordinate movement Species A particular type of organism, such as a great white shark; closely related species are grouped together into a genus. Spiracle A small opening behind a shark’s eye; water entering the spiracle passes over the gills and then exits through the gill slits. Tapitum lucidum 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 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 Ventral Lower or bottom; used here to refer to the lower or “belly” surface of an animal

Glossary Vertebrate

An animal with a backbone; fishes, amphibians, reptiles, birds, and mammals are all vertebrates.

Weather

To be worn away by exposure to wind, rain, sunlight, freezing, and thawing, etc.

91

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: Uni verse 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.

92

biliography

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.

93

94

biliography

“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.

biliography

“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.

95

further r esourCes 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

Futhe resouces

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.

97

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

98

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

D

deep water, 75–77 dentine, 62–63 Devonian Cleveland shales, 53–55 99

100

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

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

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

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

101

102

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

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

Megalodon Fact or Fiction

Recommend Documents