Dinosaurs! Read online

  The author and editor would like to thank Dr. John S. McIntosh, Professor Emeritus, Wesleyan University, for his assistance in the preparation of this book.

  Text copyright © 2005 by Dr. Robert T. Bakker.

  Illustrations copyright © 2005 by Luis V. Rey.

  All rights reserved under International and Pan-American Copyright Conventions. Published in the United States by Random House Children’s Books, a division of Random House, Inc., New York, and simultaneously in Canada by Random House of Canada Limited, Toronto.

  randomhouse.com/kids

  Library of Congress Cataloging-in-Publication Data

  Bakker, Robert T.

  Dinosaurs! / by Robert T. Bakker; illustrated by Luis V. Rey. — 1st ed.

  p. cm. — (Random House pictureback reader)

  ISBN: 978-0-375-83141-6 (trade)

  ISBN: 978-0-307-98269-8 (eBook)

  1. Dinosaurs—Juvenile literature. I. Rey, Luis V., ill. II. Title. III. Series.

  QE861.5.B344 2005 567.9–dc22 2004014240

  PICTUREBACK, RANDOM HOUSE and colophon, and PLEASE READ TO ME and colophon are registered trademarks of Random House, Inc.

  v3.1

  Title Page

  Copyright

  First Page

  Dinosaurs ruled the world for 160 million years. Some had fins. Some had big horns. Some had armor like a tank. The biggest were ten times larger than an elephant!

  We find out about dinosaurs by digging up fossils—bones and footprints buried in sand and mud that’ve turned into rock. That’s what I do. I’m a paleontologist (PAY-lee-un-TOL-uh-jist).

  Dinosaurs didn’t all live at the same time. There were three dinosaur periods—the Triassic (try-ASS-ick), the Jurassic (juh-RASS-ick), and the Cretaceous (krih-TAY-shus). At the end of each period, many kinds of animals died out—they became extinct.

  The three periods together make up the Mesozoic (MES-uh-ZOH-ick) Era. Almost all the dinosaurs died out at the end of the Mesozoic, 65 million years ago.

  The earliest dinosaurs were little meat-eaters, like Chindesaurus (CHIN-dee-SAW-rus). It lived in the Late Triassic Period. Chindesaurus had to be careful. Giant meat-eaters like Smilosuchus (SMY-luh-SOOK-us), a relative of crocodiles, liked to eat these small early dinosaurs.

  Smilosuchus lived in lakes and rivers. Another giant crocodile relative, Poposaurus (POH-poh-SAW-rus), chased Chindesaurus on land. But the early dinosaurs survived! And some grew bigger and BIGGER!

  Many dinosaurs became huge—bigger than elephants—in the Jurassic Period! Stegosaurus (STEG-uh-SAW-rus) lived in the Late Jurassic. It was a plant-eater with armor plates sticking out of its back and sharp spikes on its tail.

  Stegosaurus fought a big Jurassic meat-eater called Allosaurus (AL-uh-SAW-rus). We dug up an Allosaurus skeleton that had a hole in its hipbone. The hole fit the tail spike of a stegosaur. So we know the stegosaur had scored a direct hit.

  Many giant long-necked dinosaurs lived in the Late Jurassic Period. We dug up the footprints of a baby Apatosaurus (uh-PAT-uh-SAW-rus). Danger was nearby! Close to the baby’s tracks we found tracks from a huge meat-eater, Torvosaurus (TOR-vuh-SAW-rus).

  But the baby Apatosaurus was safe. Right next to its tracks were the footprints of an adult Apatosaurus, probably its mother or father. An adult Apatosaurus fought with its long, whiplike tail. The tail was 30 feet long—as long as a school bus!

  Fossil teeth tell us that meat-eaters worked hard to raise their babies. Dinosaurs lost teeth when they fed. And then they grew new ones. They grew new teeth all through their lives. Crocodiles do that today.

  We dug up the bones of a Brachiosaurus (BRACK-ee-uh-SAW-rus), a Late Jurassic plant-eater. And mixed in with the bones, we found teeth from an adult and a baby Ceratosaurus (suh-RAT-uh-SAW-rus)—a meat-eater. That means the ceratosaur adult and baby ate together—just like a mom lion does with her cubs.

  During the Cretaceous Period, some dinosaurs became very fast and very smart. Deinonychus (dy-NON-ih-kus) was a meat-eater that lived in the Early Cretaceous. It was only as heavy as a big dog.

  But Deinonychus was speedy and had a big brain. Packs of Deinonychus attacked like kickboxers. They slashed with their super-sharp hind claws. That’s why Deinonychus could kill large plant-eaters like the long-tailed Tenontosaurus (teh-NON-tuh-SAW-rus).

  The Late Cretaceous dinosaurs grew the biggest fins and frills. Spinosaurus (SPY-nuh-SAW-rus) was a gigantic fish-eater with a sail on its back. The sail made its body look taller and scarier.

  Spinosaurs fought each other over the best fishing spots. They would huff and puff and stand on their tiptoes trying to frighten each other. Lizards with tall sails fight this way today.

  Parasaurolophus (PAIR-uh-SAW-ruh-LOH-fus) was a Late Cretaceous plant-eater. Its nickname is “Trombone Dinosaur.” It had a head with a crest of bone that stuck out behind. Inside the crest was a tube. When a Parasaurolophus snorted, its breath went up through the tube. The noise was so loud and so low, it made the ground shake!

  Parasaurolophus herds used the noise to call to each other miles away. Hypacrosaurus (hy-PACK-ruh-SAW-rus) was a close relative that had a curved crest on its head for noisemaking.

  Torosaurus (TOR-uh-SAW-rus) was a plant-eater with long horns. It lived 66 million years ago, at the very end of the Mesozoic Era. Torosaurus had the biggest, strongest head of any dinosaur. Its skull was eight feet long!

  Torosaurus needed its long horns and strong head to fight the meat-eater Tyrannosaurus (ty-RAN-uh-SAW-rus). Tyrannosaurus had the strongest jaws and thickest teeth of any meat-eating dinosaur. One bite could crush a hipbone or rib cage.

  Plant-eaters fought each other, too. Male plant-eaters would fight to impress females. Stygimoloch (STIJ-ih-MOH-lock) was a plant-eater the size of a sheep. It had a built-in helmet made from bone and a thick neck like a football player. One Stygimoloch would try to ram another Stygimoloch in the stomach.

  Edmontonia (ED-mun-TONE-ee-yuh) was an armored plant-eater with spikes on its shoulders. The spikes were long and sharp. One blow could kill a Tyrannosaurus.

  Microraptor (MY-kroh-RAP-tur) was a tiny relative of Deinonychus. It lived in the Early Cretaceous and was no larger than a big crow. Microraptor had long fingers with sharp claws. It could climb trees by digging its claws into the bark.

  And Microraptor could soar like a flying squirrel! Fossils dug in China show that Microraptor skin was covered in feathers, just like a bird’s!

  That means…

  …some dinosaurs are

  still alive today. All birds—ostriches and hummingbirds, eagles and parrots—came from an ancestor like Microraptor. When you pet a parakeet, you’re petting a genuine great-great-GREAT-grandchild of a dinosaur!

 

 

  Dr. Robert T. Bakker; Illustrated by Luis Rey, Dinosaurs!

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