Dinosaurs, page 1
A Note from
Mary Pope Osborne About the
When I write Magic Tree House® adventures, I love including facts about the times and places Jack and Annie visit. But when readers finish these adventures, I want them to learn even more. So that’s why my husband, Will, and my sister, Natalie Pope Boyce, and I write a series of nonfiction books that are companions to the fiction titles in the Magic Tree House® series. We call these books Fact Trackers because we love to track the facts! Whether we’re researching dinosaurs, pyramids, Pilgrims, sea monsters, or cobras, we’re always amazed at how wondrous and surprising the real world is. We want you to experience the same wonder we do—so get out your pencils and notebooks and hit the trail with us. You can be a Magic Tree House® Fact Tracker, too!
Here’s what kids, parents, and teachers have to say about the Magic Tree House® Fact Trackers:
“They are so good. I can’t wait for the next one. All I can say for now is prepare to be amazed!”
—Alexander N.
“I have read every Magic Tree House book there is. The [Fact Trackers] are a thrilling way to get more information about the special events in the story.”
—John R.
“These are fascinating nonfiction books that enhance the magical time-traveling adventures of Jack and Annie. I love these books, especially American Revolution. I was learning so much, and I didn’t even know it!”
—Tori Beth S.
“[They] are an excellent ‘behind-the-scenes’ look at what the [Magic Tree House fiction] has started in your imagination! You can’t buy one without the other; they are such a complement to one another.”
—Erika N., mom
“Magic Tree House [Fact Trackers] took my children on a journey from Frog Creek, Pennsylvania, to so many significant historical events! The detailed manuals are a remarkable addition to the classic fiction Magic Tree House books we adore!”
—Jenny S., mom
“[They] are very useful tools in my classroom, as they allow for students to be part of the planning process. Together, we find facts in the [Fact Trackers] to extend the learning introduced in the fictional companions. Researching and planning classroom activities, such as our class Olympics based on facts found in Ancient Greece and the Olympics, help create a genuine love for learning!”
—Paula H., teacher
Text copyright © 2000 by Will Osborne and Mary Pope Osborne
Illustrations copyright © 2000 by Sal Murdocca
Cover photograph copyright © Martina Pohl. All rights reserved.
All rights reserved. Published in the United States by Random House Children’s Books, a division of Random House, Inc., New York. Originally published by Random House Children’s Books, New York, in 2000.
Random House and the colophon are registered trademarks and A Stepping Stone Book and the colophon are trademarks of Random House, Inc. Magic Tree House is a registered trademark of Mary Pope Osborne; used under license.
The Magic Tree House Fact Tracker series was formerly known as the Magic Tree House Research Guide series.
Visit us on the Web!
MagicTreeHouse.com
randomhouse.com/kids
Educators and librarians, for a variety of teaching tools, visit us at
randomhouse.com/teachers
Library of Congress Cataloging-in-Publication Data Osborne, Will. Dinosaurs : a nonfiction companion to Magic tree house #1 : dinosaurs before dark / by Will Osborne and Mary Pope Osborne; illustrated by Sal Murdocca.
p. cm. — (Magic tree house fact tracker)
“A stepping stone book.”
eISBN: 978-0-307-97508-9
1. Dinosaurs—Juvenile literature. I. Osborne, Mary Pope. II. Murdocca, Sal, ill. III. Title.
QE861.5.O83 2011 567.9—dc22 2010053304
Random House Children’s Books supports the First Amendment and celebrates the right to read.
v3.1
For Marjorie Osborne
Scientific Consultant:
RAYMOND RYE, Museum Specialist, Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, D.C.
HEIDI JOHNSON, Earth Science and Paleontology, Lowell Junior High School, Bisbee, Arizona
Education Consultant:
MELINDA MURPHY, Media Specialist, Reed Elementary School, Cypress Fairbanks Independent School District, Houston, Texas
We would also like to thank Alison Brooks at George Washington University for help with our time line; Helen McGovern at the American Museum of Natural History in New York City for her kind assistance; Paul Coughlin for his imaginative photography; and at Random House, Cathy Goldsmith for her wonderful and creative design, Joy La Brack for her long hours of photo research, Mallory Loehr for her ongoing guidance and support, and most especially, our editor, Shana Corey, for her diligence, insight, and joyful enthusiasm throughout the process of creating this book.
Cover
Title Page
Copyright
Dedication
1. A World of Dinosaurs
2. Fossils
3. Dinosaur Hunters
4. Flesh-eaters
5. Plant-eaters
6. Sea Monsters and Flying Creatures
7. What Happened to the Dinosaurs?
8. Dinosaur Neighbors
Doing More Research
Index
About the Authors
Long ago, the world was very different than it is now. Today, all the land on earth is divided into seven continents. Millions of years ago, there was just one continent.
A continent is one of the earth’s large land masses.
Scientists have named that ancient continent Pangaea (pan-JEE-uh).
Some parts of Pangaea were very dry, like deserts. Other parts were damp and rainy, like swamps. There were forests and jungles, plains and mountains, rivers and lakes.
And there were dinosaurs almost everywhere.
Some dinosaurs were bigger than buildings. Others were as small as ducks.
Some dinosaurs walked on all four legs, like dogs. Others walked on two legs, like people.
Some dinosaurs had many rows of sharp teeth. Others had no teeth at all.
But in some ways, all dinosaurs were alike.
They all were reptiles. They all lived on land. They all laid eggs. They almost all had scaly skins. None of them had fur or hair.
Reptiles are cold-blooded, usually scaly-skinned animals. Snakes, turtles, and lizards are reptiles.
The Age of Reptiles
Scientists think that the first dinosaur hatched over 225 million years ago. They say almost all the dinosaurs died about 65 million years ago. That means there were dinosaurs on earth for more than 160 million years!
Almost all the dinosaurs lived during what is called the Mesozoic (mez-uh-ZO-ick) Era. Scientists also call this time the “Age of Reptiles” or the “Age of Dinosaurs.”
Scientists divide the Mesozoic Era into three parts, or periods. The first is the Triassic (try-AA-sick) Period. The middle is the Jurassic (jur-AA-sick) Period. The last is the Cretaceous (krih-TAY-shus) Period.
Different kinds of dinosaurs lived in each period. The ones we know best today lived during the Jurassic and Cretaceous periods. That’s over 60 million years before the first human was born.
So how can we know about these dinosaurs if no human has ever actually seen one?
We know about them because they left their bones and teeth and footprints all over the world.
When people find dinosaur bones today, they aren’t really finding unchanged bones. They’re finding fossils (FAH-sulz).
Fossils are any traces of life from a long-ago age.
Sometimes a dinosaur died near a stream or river. If the stream or river overflowed, the dinosaur’s body would be covered by mud and sand. Over millions of years, the mud and sand turned into solid rock. And the dinosaur’s skeleton was still inside!
At the same time, water in the earth seeped into the dinosaur’s bones. Miner-als in the water turned the bones to stone, too.
Minerals are natural substances in the earth that do not come from plants or animals.
So a dinosaur fossil is really a rock that used to be a bone buried inside another rock that used to be some mud and sand!
Fossils can tell us a lot about dinosaurs.
People used to call anything that was dug out of the ground a fossil. (Even potatoes!)
Fossil teeth can tell us the kind of food a dinosaur might have eaten. Flat teeth are good for chopping up plants. Sharp, pointed teeth are good for ripping flesh.
Fossil leg bones can tell us how a dinosaur might have walked. Long leg bones are good for fast running. Short, thick leg bones mean the dinosaur prob-ably moved slowly.
Footprint fossils can help us guess how much a dinosaur weighed. Deep footprints mean the dinosaur who made them must have been very heavy. Shal-low footprints mean the dinosaur must have been a lightweight.
Footprint fossils can even tell us how dinosaurs traveled. Many footprints going the same way mean the dinosaurs were probably moving in packs or herds. Big footprints beside little footprints mean the dinosaurs may have been traveling with their families.
Almost everything that we know about dinosaurs we know from fossils. But fossils can only give us clues about dinosaurs and the Age of Reptiles. We have to use our imaginations to picture how these amazing creatures really looked, how they lived, and how they died.
Fossils can even tell us about dinosaur eggs, dinosaur nests, and dinosaur bab
Dinosaur eggs are usually found in nests. But dinosaur nests are not like the ones birds build in trees. Most dinosaur nests were dug in sand or mud.
Scientists say that some dinosaurs returned to the same nesting grounds year after year.
The biggest dinosaur egg fossils ever found are about the size of a football. But the mother dinosaur that laid them was over 40 feet long!
Why did huge dinosaurs lay small eggs? Scientists think that if dinosaur eggs had been bigger, the shells would have been too thick for baby dinosaurs to break out of.
The first people who discovered dinosaur fossils didn’t know what they were.
The ancient Chinese thought they came from the skeletons of dragons.
Native Americans thought they came from giant snakes.
Other people who found fossils thought they came from very large elephants—or even giant humans!
In 1822, an English couple named Mary Ann and Gideon Mantell found some large fossil teeth near their home.
Gideon took the fossils to a museum and looked at them next to teeth from other animals.
Gideon didn’t see any teeth that were like the fossils he and Mary Ann had found. He decided the fossils belonged to an animal that didn’t live on earth anymore.
Gideon thought the fossil teeth looked most like giant iguana teeth. So he called the animal they came from an Iguanodon (ih-GWAH-nuh-don).
An iguana is a large South American lizard.
At about the same time, a professor in England named William Buckland was studying the fossil of a very large jawbone. Dr. Buckland decided that this fossil was also from an animal that no longer lived on earth. He called the creature it came from Megalosaurus (MEG-uh-luh-SOAR-us). That means “big lizard” in Greek.
Nearly 20 years later, an English scientist named Richard Owen studied the Iguanodon and Megalosaurus fossils. He could tell that both these creatures were totally different from any animals still living on earth. He decided that creatures like these should have a special name.
Richard Owen chose a name that means “terrifying lizards” in Greek.
The name was dinosaurs.
After these early fossil discoveries, people became very interested in dinosaurs. Scientists wanted more fossils to study. Museums wanted dinosaur skeletons to put on display. There was a race to find more bones!
How Dinosaurs Get Their Names
Dinosaur hunters use Latin and Greek words to make up names for the different kinds of dinosaurs they discover.
Some are named for the place where they were found. Alamosaurus (AL-uh-muh-SOAR-us) fossils were found near the Alamo, in Texas.
Some are named after the person who discovered them. Marshosaurus (MARSH-uh-SOAR-us) was named for Othniel Charles Marsh, a famous dinosaur hunter.
Some are named for the way they looked. Corythosaurus (KOR-ih-thuh-SOAR-us) means “helmet lizard.”
The Bone Wars
Scientists who study fossils are called paleontologists (PAY-lee-un-TAH-luh-jists). Two of the most famous paleontologists were Othniel Charles Marsh and Edward Drinker Cope. They both were Americans who started hunting for fossils in the 1870s.
Marsh and Cope were so eager to find new fossils that they became enemies. They hid their discoveries from each other. They sent spies into each other’s camps. They even tried to steal each other’s bones!
These two dinosaur hunters fought for 20 years. But their bone battles led to the discovery of more than 130 different kinds of dinosaurs.
Over the last hundred years, people have hunted for dinosaurs all over the world. Dinosaur fossils have been found on every continent and in almost every country. Each time a dinosaur hunter digs up a fossil, we learn a little more about the Age of Dinosaurs.
Bone-Hunting Tools
Dinosaur hunters use lots of tools. Here are some things they always take along when they go digging for fossils.
Even famous dinosaur hunters sometimes goof!
The Name Game
For many years people visited museums to see a dinosaur called Brontosaurus (BRON-tuh-SOAR-us). But O. C. Marsh, the scientist who named it, did not realize that he had already given a differ-ent name to the same dinosaur. Marsh’s Brontosaurus was also missing its head, so he put the skull of another dinosaur on his reconstruction because he thought the real skull would look about the same. He was wrong! Finally the name was changed back to Apatosaurus (uh-PAT-uh-SOAR-us), and the head was replaced.
The Wrong End
Early in his career, E. D. Cope dug up the fossil bones of a giant sea reptile. When he put the bones together, he made a big mistake. He mixed up the tail bones with the neck bones. And he stuck the animal’s head on the end of its tail!
Horn or Claw?
When Gideon Mantell was studying Iguanodon fossils, he thought one of the dinosaur’s claws was a giant horn. He drew a picture of an Iguanodon with its claw growing out of its snout!
The Wrong Robber
About 80 years ago, dinosaur hunters in Asia found the fossil of a small dinosaur near a nest full of fossilized eggs. They thought the dinosaur was about to raid the nest. So they named it Oviraptor (OH-vuh-RAP-tur), which means “egg robber.” But paleontologists recently discovered that the Oviraptor wasn’t stealing another dinosaur’s eggs. It was sitting on its own nest to help the eggs hatch!
As dinosaur hunters dug up more and more fossils, they realized there were hundreds of different kinds of dinosaurs.
Soon they started sorting them into groups. The simplest way to sort dinosaurs is by what they ate.
Some dinosaurs ate flesh. Others ate only plants.
How Do We Know What Dinosaurs Ate?
Paleontologists use clues from fossils to figure out the kind of food different dinosaurs ate.
Sometimes bones from another animal are found inside the fossil of a dinosaur. That means the dinosaur must have been a flesh-eater.
Some fossil teeth are short and flat. They wouldn’t have been good for ripping flesh. So the dinosaur they belonged to must have been a plant-eater.
Sometimes a dinosaur’s droppings were fossilized. If the droppings contain seeds, it means the dinosaur was a plant-eater. If they contain ground-up pieces of bone, the dinosaur must have been a flesh-eater.
Paleontologists think all of the very first dinosaurs were flesh-eaters.
The earliest dinosaur fossil ever discovered was from a flesh-eater about the size of a goose. Paleontologists named this dinosaur Eoraptor (EE-oh-RAP-tur). Eoraptor means “dawn robber.” Eoraptor lived on earth over 225 million years ago—at the dawn of the age of dinosaurs.
Paleontologists think Eoraptor and other early dinosaurs probably ate insects and small lizards.
Flesh-eating dinosaurs came in many sizes. But they all had a similar shape.
The flesh-eaters walked and ran on their hind legs. They usually had small arms. Most of them had long, strong tails. Their mouths were full of very sharp teeth.
Paleontologists think the flesh-eaters hardly ever stood up straight when they ran. They used their tails for balance and leaned very far forward.
Flesh-eating dinosaurs had different ways of feeding themselves. Some hunted and killed smaller dinosaurs and other animals. Animals who hunt other animals for food are called predators. The animals they hunt are called their prey.
