Scott Foresman Science
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Genre Comprehension Skill Text Features Science Content Nonfi ction Summarize • Captions Rocks and • Labels Minerals • Text Boxes • Glossary Scott Foresman Science 4.8 ì<(sk$m)=bdiicb<ISBN 0-328-13882-7 +^-Ä-U-Ä-U 13882_01-04_CVR_FSD.indd Cover1 5/11/05 1:22:25 PM Vocabulary Extended Vocabulary What did you learn? igneous rock anatomy luster Cretaceous 1. How is a fossil formed? metamorphic rock extinct mineral Jurassic 2. What is Mary Anning famous sediment paleontology for discovering? sedimentary rock protruding quarry 3. What led to the feud between Othniel Charles Marsh and Edward Drinker Cope? 4. The people in this book enjoyed the study of fossils. Explain on your own paper why you think someone would want to become a paleontologist. Include details from the book to support your answer. 5. Summarize Write a brief summary of the life and work of Barnum Brown. Picture Credits Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd). 4 Richard T. Nowitz/Corbis; 6 (CR) ©The Natural History Museum, London; 8 (TR) Photo Researchers, Inc.; 12 (T, B) Bettmann/Corbis; 14 (TR) ©The Natural History Museum, London. Scott Foresman/Dorling Kindersley would also like to thank: 9 (BR) Natural History Museum, London/DK Images; 15 (TR) Natural History Museum, London/DK Images. by Joyce A. Churchill Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson. ISBN: 0-328-13882-7 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05 13882_01-04_CVR_FSD.indd Cover2 13882_05-20_FSD.indd 1 5/11/05 1:22:451:26:11 PM What You Already Know You can learn a great deal about Earth, and the Igneous rocks form from molten (melted) or partly plants and animals that live on it, from rocks. Rocks can molten rock deep below Earth’s surface. Rock is melted form both above and below the surface of Earth. They by the intense heat that causes volcanic eruptions. Dead form in many layers. By studying the different layers, plant and animal matter combines with bits of rock to scientists can fi gure out Earth’s past and present. form soil, which settles on the bottoms of lakes, rivers, Minerals, which are natural, nonliving crystals, and oceans. This is called sediment. This material can combine to form rocks. Scientists can identify be moved by water, ice, wind, or gravity to form layers. rock-forming minerals through their properties. Color These layers press together and become sedimentary and luster are properties of minerals that relate to the rock. Metamorphic rock can form from any kind of way light refl ects from the surface of rocks. A mineral’s rock as a result of heat and pressure deep below hardness is measured by how easily it can be scratched. Earth’s surface. The color of the powder that the mineral leaves behind after being scratched is another property called streak. Fossils in sedimentary rock give scientists clues to Three kinds of rock have been found on Earth: what lived on Earth hundreds of millions of years ago. igneous, metamorphic, and sedimentary. All three kinds Fossils are the bones, teeth, can change from one to another over time. This process leaves, or any evidence is called the rock cycle. of a living thing from long ago. Scientists igneous rock metamorphic rock sedimentary rock must be good detectives to fi nd and fi gure out the clues. fossil of a dinosaur footprint 2 3 13882_05-20_FSD.indd 2 5/11/05 1:26:17 PM 13882_05-20_FSD.indd 3 5/11/05 1:26:19 PM Layers of Clues Do you like to spend hours solving riddles, playing Scientists have developed games, and fi tting together puzzles? Then you might want a geologic time scale to study to become a paleontologist. You would be a scientist who fossils in the layers and layers studies fossils to discover what Earth was like long ago. of sedimentary rock. They agree You would be a fossil detective! that dinosaurs fi rst appeared, lived, fossilized fi sh Paleontologists search for the answers to many and then disappeared during the Mesozoic era on their questions. What creatures lived on Earth? What did they scale. This is the middle period in the history of Earth. eat? Were these creatures mammals? Were they reptiles? Using pieces of skeletons and other fossils as clues, Were they birds? Why did they disappear? The list of scientists have fi gured out what some dinosaurs looked questions goes on and on. like and how they lived. But before they can fi gure all Over the past 200 years, fossil detectives have that out, they fi rst have to fi nd the pieces and put answered some of these questions. Giant birds and them together! reptiles that we now call dinosaurs lived from 65 million to over 200 million years ago. Scientists know that these strange creatures lived on each of Earth’s continents. How a Fossil Is Formed Fossils are the The hard parts of the After millions of remains of plants animal, such as the years of erosion and and animals that bones, are preserved weathering, the once lived. When a in the layers. Eggs, bones appear at the dinosaur died, its skin, and even surface. They poke body was slowly footprints of dinosaurs through the soil, A paleontologist covered by layers of harden as they slowly where they are sedimentary rock. become fossils. discovered. searches for fossils. 4 5 13882_05-20_FSD.indd 4 5/11/05 1:26:22 PM 13882_05-20_FSD.indd 5 5/11/05 1:26:41 PM Paleontology Pioneers Before the 1800s, a few large fossil bones were Plesiosaurus fossil found sticking out of the ground. No one knew what they were from. Once scientists identifi ed the fossils as the remains of dinosaurs, they became fascinated with these mysterious creatures. When she was twelve years old, Mary Anning Anning uncovered the skeleton of a marine You might not think of a young, reptile in a cliff. She chipped away the rock to uneducated girl as being an important reveal four fl ippers and a long jaw with sharp teeth. dinosaur fossil collector, but Mary This was the fi rst Ichthyosaurus ever found, and it was Anning was one. Anning, born in 1799, more than thirty-two feet long. This was just one of and her brother collected fossils with Anning’s many discoveries. their father. After his death, they The leading scientists of the time did not want Mary Anning continued scouring the cliffs near their to give Anning credit for her fi ndings. Finally, after home in Lyme Regis in southern England. They sold Anning’s many years of hard work, they recognized the fossils they found to help support the family. the importance of her discoveries. pick Tools for Fossil Hunting Anning and her brother chisel brush looking for fossils Uncovering a skeleton embedded in rock takes time and patience. The hammer and chisel remove fossils from a rock. The pick chips away dirt from a bone. The brush dusts hammer away any remaining dirt. 6 7 13882_05-20_FSD.indd 6 5/11/05 1:26:45 PM 13882_05-20_FSD.indd 7 5/11/05 1:26:50 PM Gideon Mantell Othniel Charles Marsh Gideon Mantell was a doctor, Othniel Charles Marsh was a but he loved hunting for fossils. As a respected vertebrate paleontologist in young boy he hunted for them in the the 1800s. Marsh was an “armchair quarries near his home in Lewes, paleontologist,” who collected fossils Sussex, England. as a hobby. He didn’t like to go into In 1822, he and his wife were Gideon Mantell the fi eld to collect the fossils. Marsh Othniel Charles Marsh exploring Tilgate Forest, a quarry near their preferred to quietly sort and catalog home. They stumbled across a large, fossilized tooth. fossils at the Peabody Museum at This was unlike anything the doctor had seen before, Yale University, where he worked. so he took it to several leading paleontologists to fi nd His friend Edward Drinker out what it was. One scientist told him that it was a Cope, a younger paleontologist, tooth from a rhinoceros. Mantell didn’t believe him. had proudly assembled the Finally, in 1825, the tooth Mantell found skeleton of the Elasmosaurus, was linked to the Iguanodon, a large, a giant dinosaur. So Marsh went to plant-eating dinosaur. look at the skeleton. He quickly pointed out to Cope where the Mantell lecturing body parts were mixed up. This on his discoveries started a bitter feud between the Marsh discussing his two men that lasted more than fossil fi nds twenty years. fossilized Keeping Records Iguanodon tooth Keeping accurate records of where bones are found is important. Paleontologists can match the location of fossils in sedimentary rock with the times that animals lived on the Earth.