CSI CHAPTERS
NONFICTION
What has over 250 razor-sharp teeth,
eyes as big as basketballs, and a bite
more powerful than a T. rex?
Read on, if you dare…
terrifying beast of the deep
TRY…
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PL-6355
PL-6355
LEVEL
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Copyright © 2011 South Pacific Press Ltd/Pacific Learning Inc.
All rights reserved. No part of this book may be reproduced in any form
without the written permission of the publisher.
Written by Janice Marriott
Edited by Alison Auch
Designed by ThinkSpace Design
Illustrations by Spike Wademan
Published by South Pacific Press, P.O. Box 19088
Wellington, New Zealand 6149
www.csi-literacy.com
PL-6355
ISBN: 978-1-60457-871-3
Printed in the United States of America
C ntents
The Beast Attacks
2
When Was the Megalodon Alive?
6
How Do We Know about the Megalodon?
8
What Big Teeth You Have!
11
Open Wide!
16
How Big Was the Megalodon?
18
So Long, Megalodon!
20
Glossary
24
No one knows how the megalodon
became extinct after millions of
years of being the most terrifying
predator in the world. Some
scientists say that the megalodon
may have become extinct because
the oceans cooled down. About
3 to 5 million years ago, the lands
of North and South America became
linked. Scientists think this changed
the currents of the Earth’s oceans, and
that this change caused the ice age
that followed.
6
This ice age started about 2.5 million years ago, and during
that time, huge ice sheets spread out from the North and South
Poles and covered all of Antarctica and most of North America.
The ice age made the oceans much shallower (because lots of
water was trapped in ice) and made the water much colder. The
megalodon was huge, strong, and fierce, but it lived in warm
waters and probably couldn’t survive in the cold.
North and South America
became linked during the
time of the megalodon.
Megalodons also gave birth to their young in safe, warm places
that scientists call shark nurseries. There probably weren’t many
places left that made good nurseries during the ice age, so many
megalodon babies probably died shortly after birth.
7
Index
adapted – became used to a new situation
blubber – the layer of fat underneath the skin of whales or other sea mammals
blunt – not sharp, dull
camouflaged – when an animal or thing is blended into its surroundings so that
it is hidden
cartilage – bendy tissue found in the body
civilization – an advanced group of people who have things like written language
and laws
decaying – rotting
earthquakes 3, 6, 7 – sudden and violent movements of the Earth’s surface
expose – to show something that couldn’t be seen before
extinct – species is no longer alive
ferocious – extremely fierce
flexible – easily bent
fossil 3 – a record of earlier life buried in rock
ice age – one of the periods of time when ice sheets covered large parts of the Earth
landmasses – large bodies of land
landslides 3 – downward movements of earth and rock
ligaments – tough, string-like tissues that attach muscle to bone
massive – big and heavy, huge
predator 3 – an animal that kills and eats other animals
prehistoric – in a time before humans started recording history
preserved – kept safe from loss or decay
prey – an animal that is caught and eaten by another animal
scientists – people who have jobs in or study science
sensors – parts of an animal’s body that help it notice changes around it
sieve – a tool that separates bigger things from smaller things
thrived – were healthy and strong
volcanic eruptions 3 – the sudden, violent explosion of steam and volcanic materials
Academic Vocabulary Key
1 English Language Arts
2 Mathematics
3 Science
8
4
5
6
7
Economics
Civics
Geography
General History
8 US History
9 World History
10 Health
11 Physical Education
12
13
14
15
Technology
General Arts
Dance/Music
Theater/Visual Arts
appearance 4–5, 10–11, 16–19
babies 21
blue whales 18
camouflage 2, 4
diet 2–3, 16–17, 22
existence 4, 6–7
extinction 20–22
fossils 5, 8–9, 11, 22
great white shark 10, 14–15
habitat 7, 14, 21–22
ice age 20–21
jaws 13, 16-17
krill 18
paleontologist 9
shark nurseries 21
size 18–19, 22
teeth 11–16
weight 18–19
Acknowledgments
Photography and artwork: (cover and contents page, pp. 2–3, p. 4, p. 17 top) Spike Wademan; pp. 4–5, 105680943/Shark ©2010
Thinkstock/iStockphoto.com; (pp. 6–7) 95244946/Animal silhouettes © 2010 Thinkstock/iStockphoto.com; (p. 8) 93443992/Fossil
© 2010 Photos.com, a division of Getty Images; (p. 9) 95143815/Boy geologist © 2010 Thinkstock/Hemera; (p. 10) RTXL60Q/Great
White © REUTERS/Sea Change Technology; (p. 11) 91090184/Megalodon tooth © 2010 Photos.com, a division of Getty Images;
(p. 12) 91080045/Megalodon teeth © 2010 Photos.com, a division of Getty Images; (p. 13 top) 76549152/Boy with gap in teeth
© 2010 Thinkstock/Photodisc; (p. 13 bottom) © Kate W/CC-BY-SA-2.0; (p.14) JR002726/Teeth comparison © TRANZ/Jeffrey
L. Rotman/CORBIS; (p. 15, p. 16) Images are in public domain; (p. 17 bottom) 91285638/Megalodon jaw © Getty Images; (p. 19)
91683855/Basketball court © 2010 Thinkstock/iStockphoto.com; (pp. 20–21) 89097558/Boulders in ice age © 2010 Photos.com,
a division of Getty Images; (pp. 22–23) 101534676/Shark1 © 2010 Thinkstock/Hemera. All photographs and images have been
used with permission and copyright remains with the individual and/or the organization. Every effort has been made to contact
copyright holders of material reproduced in this book. If notified, the publishers will be pleased to rectify any errors or omissions
at the earliest opportunity.