Fossils (the Restless Earth)

Th s s e Earth l t s e eR Fossils THE REsTlEss EARTH Earthquakes and Volcanoes Fossils Layers of the Earth Mountains and Valleys Rivers, Lakes, and Oceans Rocks and Minerals e s l T s s e e aRTh R e h T Fossils gary raham Fossils Copyright © 2009 by Infobase Publishing All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information, contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Raham, Gary. Fossils / by Gary Raham. p. cm. — (Restless earth) Includes bibliographical references and index. ISBN 978-0-7910-9703-8 (hardcover) 1. Fossils—Juvenile literature. I. Title. QE714.5.R34 2008 560—dc22 2008027077 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Text design by Erika K. Arroyo Cover design by Ben Peterson Printed in the United States of America Bang EJB 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. All links and Web addresses were checked and verified to be correct at the time of publication. Because of the dynamic nature of the Web, some addresses and links may have changed since publication and may no longer be valid. Contents ▲▲▲ 1 Fossils: From Natural Curiosities to Scientific Treasures 2 3 4 5 6 7 The Tortuous Road to Fossilhood 22 So Many Fossils, So Little Time 38 Marking Turning Points in Evolution 50 Finding and Excavating Fossils 66 Fossils in the Human Family 78 Glossary 91 Bibliography 97 Further Reading 101 Picture Credits 104 Index 105 About the Author 111 1 Fossils: FROM NATURAL CURIOSITIES TO SCIENTIFIC TREASURES ▲▲▲ The tyrannosaur hurt. The breeze off the great water relieved the sun’s heat, but her leg and side still ached where blood oozed from the gashes created by Three Horn’s nose spike. She blinked her eyes, but the tattered fern fronds nearby failed to focus properly. Suddenly, the sky tilted alarmingly and one side of her body struck the cool earth. She found that she could not move. The familiar forest odors of pine resins and molding leaf litter settled about her as the world became silent and faded to black. MORE THAN 65 MILLION YEARS PASSED. In the year 1992, a man named Charles Fickle took a walk with his dog through a half-built subdivision in Littleton, Colorado. He (or maybe his dog) found a large, rock-hard bone sticking out of the ground and suspected that it might be a fossil—the (usually) mineralized remains of a once-living creature. Fickle alerted the Denver Museum of Nature and Science. In response, the museum sent paleontologists—scientists who specialize in studying the remains of ancient plants and animals—to the site. They unearthed the entire right leg, ten teeth, a shoulder 7    Fossils blade, and a tail vertebra, all belonging to the meat-eating dinosaur Tyrannosaurus rex. Fickle’s dog did not get to chew on the bones, but Fickle got to chew on an unsettling thought: The world was once a vastly different place from what it is today. What other fossil mysteries lie buried in the Earth awaiting discovery? Can these fragments of former lives serve as a lens through which prehistoric wo