Isabella Brooklyn Illustrated by Haude Levesque

Transcription

1 Isabella Brooklyn Illustrated by Haude Levesque A Charlesbridge Imprint

2 Text copyright 2010 by Sudipta Bardham Quallen Illustrations copyright 2010 by Haude Levesque All rights reserved, including the right of reproduction in whole or in part in any form. Charlesbridge and colophon are registered trademarks of Charlesbridge Publishing, Inc. An Imagine Book Published by Charlesbridge 85 Main Street Watertown, MA (617) Library of Congress Cataloging-in-Publication Data Brooklyn, Isabella. If you were raised by a dinosaur / Isabella Brooklyn ; illustrated by Haude Levesque. p. cm. isbn Dinosaurs Juvenile literature. 2. Dinosaurs Behavior Juvenile literature. 3. Dinosaurs Growth Juvenile literature. 4. Parental behavior in animals Juvenile literature. I. Levesque, Haude, ill. II. Title. QE861.5.B dc Designed by Marc Cheshire

3 Contents If You Were Raised by a Dinosaur What Came First, the Dino or the Egg? Were Dinosaurs Good Parents? The Case of the Lizard King The Future of Studying the Past A Word about Wording Pronunciation Guide Index

4 If You Were Raised By a Dinosaur People do it every day. So do birds, monkeys, butterflies, and platypuses. We have babies. For the 160 million years that the dinosaurs walked the earth, they did it, too. Every living animal reproduces in some way, but how each cares for its young differs from species to species. Humans buy them toys, create nurseries, and organize playdates. Birds built nests and sit patiently on their eggs to warm them with their own body heat. After the eggs hatch, the parents provide food and protection until the chicks are ready to take care of themselves. Sea turtles also build nests for their eggs. But once the eggs have been laid, the mother leaves them behind and never returns. The father sea turtle isn t involved at all. It s hard for paleontologists to know for sure how dinosaurs took care of their babies. After all, there are no living dinosaurs All living animals reproduce, but how they care for their young differs from species to species. 5

5 IF YOU WERE R AISED BY A DINOSAUR to observe in their natural environments. The only way scientists have to learn about dinosaurs and their parenting techniques is by studying the clues that have been left behind. But even this is easier said than done. The first dinosaurs appeared 230 million years ago, and the last to walk the earth were around until about 65 million years ago. That s a really long time for fossils to wait to be excavated! Scientists have found lots of adult dinosaur bones, but the bones of young dinosaurs are harder to find. Their smaller, less-formed skeletons are easily damaged by trampling feet, geological shifts, or the jaws (and digestive systems) of hungry predators. Still, there are many things we have come to know or at least think we know about dinosaur mommies, daddies, and babies. But to understand all of this, we need to start at the beginning. WHO WERE THE DINOSAURS? The geological timescale is divided into three eras: the Paleozoic, the Mesozoic, and the Cenozoic. The Paleozoic era lasted from 250 to 550 million years ago. During this era, amphibians, fish, and land plants ruled the earth. Next came the Mesozoic era. The Mesozoic era is divided into the Triassic, Jurassic, and Cretaceous periods. The first dinosaurs evolved during the Triassic period, between 206 and 250 million years ago. During the Jurassic period, which extended from 144 to 204 million years ago, the number of 6 Scientists learn about dinosaurs by studying their bones.

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8 IF YOU WERE R AISED BY A DINOSAUR dinosaur species expanded, and the first birds appeared. Flowering plants came into being and dinosaurs became extinct in the Cretaceous period. The Cenozoic era, which is the period we live in, started 65 million years ago. Mammals, including humans, evolved during this time. Dinosaurs shared the earth with lots of other animals. One of the problems that scientists face when studying fossils is that not all bones from millions of years ago are actually from dinosaurs. In addition to birds and plants, dinosaurs shared the earth with other reptiles, like aquatic plesiosaurs, flying pterosaurs, and land-dwelling Dimetrodons. They even walked alongside some ancient mammals, like the badger-sized Didelphodon which likely scavenged dinosaur eggs for food and Repenomamus robustus, whose fossil was found with the remains of a small dinosaur in its stomach. These creatures are often grouped with dinosaurs, but they definitely were not. When scientists talk about dinosaurs (a term coined by Sir Richard Owen in 1842 that means terrifying lizard ), they mean a specific group of reptiles that lived only in the Mesozoic era. Paleontologists look at several factors to decide if the fossil they have found comes from a dinosaur. First, dinosaurs lived only on land. There is no evidence that any dinosaur could fly, and though many species lived near bodies of water, they definitely did not live in the water. 9