4 8 fossil detectives (earth science)

Genre

Nonfiction

Comprehension Skill

Summarize

Text Features

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•
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Captions
Labels
Text Boxes
Glossary

Science Content

Rocks and
Minerals

Scott Foresman Science 4.8

ISBN 0-328-13882-7

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Vocabulary

Extended Vocabulary

igneous rock
luster
metamorphic rock
mineral
sediment
sedimentary rock

anatomy
Cretaceous
extinct
Jurassic
paleontology
protruding
quarry

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.

What did you learn?
1. How is a fossil formed?
2. What is Mary Anning famous
for discovering?
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.

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.
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

by Joyce A. Churchill

What You Already Know
You can learn a great deal about Earth, and the
plants and animals that live on it, from rocks. Rocks can
form both above and below the surface of Earth. They
form in many layers. By studying the different layers,
scientists can figure out Earth’s past and present.
Minerals, which are natural, nonliving crystals,
combine to form rocks. Scientists can identify
rock-forming minerals through their properties. Color
and luster are properties of minerals that relate to the
way light reflects from the surface of rocks. A mineral’s
hardness is measured by how easily it can be scratched.
The color of the powder that the mineral leaves behind
after being scratched is another property called streak.
Three kinds of rock have been found on Earth:
igneous, metamorphic, and sedimentary. All three kinds
can change from one to another over time. This process
is called the rock cycle.
igneous rock

metamorphic rock

sedimentary rock

Igneous rocks form from molten (melted) or partly
molten rock deep below Earth’s surface. Rock is melted
by the intense heat that causes volcanic eruptions. Dead
plant and animal matter combines with bits of rock to

form soil, which settles on the bottoms of lakes, rivers,
and oceans. This is called sediment. This material can
be moved by water, ice, wind, or gravity to form layers.
These layers press together and become sedimentary
rock. Metamorphic rock can form from any kind of
rock as a result of heat and pressure deep below
Earth’s surface.
Fossils in sedimentary rock give scientists clues to
what lived on Earth hundreds of millions of years ago.
Fossils are the bones, teeth,
leaves, or any evidence
of a living thing from
long ago. Scientists
must be good
detectives to find
and figure out
the clues.
fossil of a
dinosaur footprint

2

3


Layers of Clues
Do you like to spend hours solving riddles, playing
games, and fitting together puzzles? Then you might want
to become a paleontologist. You would be a scientist who
studies fossils to discover what Earth was like long ago.

You would be a fossil detective!
Paleontologists search for the answers to many
questions. What creatures lived on Earth? What did they
eat? Were these creatures mammals? Were they reptiles?
Were they birds? Why did they disappear? The list of
questions goes on and on.
Over the past 200 years, fossil detectives have
answered some of these questions. Giant birds and
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.

A paleontologist
searches for fossils.

4

Scientists have developed
a geologic time scale to study
fossils in the layers and layers
of sedimentary rock. They agree
fossilized fish
that dinosaurs first appeared, lived,
and then disappeared during the Mesozoic era on their
scale. This is the middle period in the history of Earth.
Using pieces of skeletons and other fossils as clues,
scientists have figured out what some dinosaurs looked
like and how they lived. But before they can figure all
that out, they first have to find the pieces and put
them together!

How a Fossil Is Formed

Fossils are the
remains of plants
and animals that
once lived. When a
dinosaur died, its
body was slowly
covered by layers of
sedimentary rock.

The hard parts of the
animal, such as the
bones, are preserved
in the layers. Eggs,
skin, and even
footprints of dinosaurs
harden as they slowly
become fossils.

After millions of
years of erosion and
weathering, the
bones appear at the
surface. They poke
through the soil,
where they are
discovered.

5


Paleontology Pioneers
Before the 1800s, a few large fossil bones were
found sticking out of the ground. No one knew what
they were from. Once scientists identified the fossils as
the remains of dinosaurs, they became fascinated with
these mysterious creatures.

Mary Anning
You might not think of a young,
uneducated girl as being an important
dinosaur fossil collector, but Mary
Anning was one. Anning, born in 1799,
and her brother collected fossils with
their father. After his death, they
Mary Anning
continued scouring the cliffs near their
home in Lyme Regis in southern England. They sold
the fossils they found to help support the family.

Plesiosaurus fossil

When she was twelve years old,
Anning uncovered the skeleton of a marine
reptile in a cliff. She chipped away the rock to
reveal four flippers and a long jaw with sharp teeth.
This was the first Ichthyosaurus ever found, and it was
more than thirty-two feet long. This was just one of

Anning’s many discoveries.
The leading scientists of the time did not want
to give Anning credit for her findings. Finally, after
Anning’s many years of hard work, they recognized
the importance of her discoveries.

pick
Anning and her brother
looking for fossils

brush

hammer

6

chisel

Tools for Fossil Hunting
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
away any remaining dirt.

7

Gideon Mantell

Othniel Charles Marsh

Gideon Mantell was a doctor,
but he loved hunting for fossils. As a
young boy he hunted for them in the
quarries near his home in Lewes,
Sussex, England.
Gideon Mantell
In 1822, he and his wife were
exploring Tilgate Forest, a quarry near their
home. They stumbled across a large, fossilized tooth.
This was unlike anything the doctor had seen before,
so he took it to several leading paleontologists to find
out what it was. One scientist told him that it was a
tooth from a rhinoceros. Mantell didn’t believe him.
Finally, in 1825, the tooth Mantell found
was linked to the Iguanodon, a large,
plant-eating dinosaur.

Othniel Charles Marsh was a
respected vertebrate paleontologist in
the 1800s. Marsh was an “armchair
paleontologist,” who collected fossils
as a hobby. He didn’t like to go into
Othniel Charles Marsh
the field to collect the fossils. Marsh
preferred to quietly sort and catalog
fossils at the Peabody Museum at

Yale University, where he worked.
His friend Edward Drinker
Cope, a younger paleontologist,
had proudly assembled the
skeleton of the Elasmosaurus,
a giant dinosaur. So Marsh went to
look at the skeleton. He quickly
pointed out to Cope where the
body parts were mixed up. This
started a bitter feud between the
two men that lasted more than
Marsh discussing his
fossil finds
twenty years.

Mantell lecturing
on his discoveries

fossilized
Iguanodon tooth

8

Keeping Records
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.

9


Edward Drinker Cope

Werner Janensch

Edward Drinker Cope was a hardworking paleontologist who looked for
dinosaur remains. He explored in the
western United States between 1870
and 1890.
Edward Drinker Cope
Some of the biggest dinosaur
graveyards are in the western United
States. The bones of giant animals such as the Diplodocus,
Stegosaurus, and Triceratops have been found there.
In the science of paleontology, if you find a new
dinosaur species, you have the honor of naming it.
After Othniel Charles Marsh insulted Cope, they became
enemies. They competed in the West to find, document,
and name new species. This was called the Bone War.

The huge Brachiosaurus, or “arm
lizard,” was a giant land animal from
the late Jurassic period. Werner
Janensch, a German paleontologist,
first collected its bones during an
Werner Janensch
expedition to East Africa, in what is

now the country of Tanzania, from 1909 to 1913.
Janensch shipped tons of bones back to the Natural
History Museum of Berlin. He and other scientists
unpacked the bones and assembled them piece by piece
into a giant skeleton. Their work was like putting
together a jigsaw puzzle that
is as tall as a four-story
building!
Janensch and
workers with a
Brachiosaurus bone

Cope used dynamite to blast his
way through to hidden bones.

Extracting Fossils

removing a fossil

Fossils have to be chipped
out of rocks with great care.
The more carefully
preserved the fossil is,
the more scientists can
learn from it.

10

11

Barnum Brown
Barnum Brown was named after
P. T. Barnum, the nineteenth-century
American showman and circus
founder. He began picking up the
fossils of extinct animals as a boy in
Kansas. He collected fossils for more
Barnum Brown
than sixty-six years as a paleontologist.
Brown loved working in the field collecting fossils.
He searched for dinosaur remains in the United States,
Canada, South America, India, and Ethiopia.
Brown discovered the skeletal remains of
Tyrannosaurus rex. The T rex was displayed in the
American Museum of Natural History in New York
City, where Brown was the curator for many years.
Barnum Brown supervised the
assembly of many dinosaur
skeletons.

Brown discovered his first T rex in 1902. He
then discovered an even better skeleton in 1908.
He assembled both in the Museum of
Natural History. Years later, the first
skeleton Brown discovered was
moved to the Carnegie Museum
in Pittsburgh, Pennsylvania.
The fossils revealed that the T rex
had a huge jaw that helped it devour

nearly any food it wanted. It was
between fifteen and twenty feet tall
and almost forty feet long. It weighed
between five and seven tons.
Barnum Brown also discovered the
duck-billed Corythosaurus from the
Cretaceous period. He found its skeleton
in the Red Deer River in Alberta, Canada. Tyrannosaurus rex
Reconstructing Fossils
Putting together the
skeleton of a giant, extinct
reptile such as the Allosaurus
is a challenging job. You
must know anatomy and the
bone structure of similar
animals in order to put each
part in the right place.
reconstructing an
Allosaurus skeleton

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13


John R. Horner
John R. Horner had trouble in
school as a boy because of a learning
disability. Yet he has collected and
cataloged fossils since he was seven

years old.
In 1978, he found the first nest of
baby dinosaurs in Montana. He named
John R. Horner
this new dinosaur the Maiasaura. The
babies were about the size of a crow.
The next year he found the remains of a herd of
more than ten thousand Maiasaurs. He also has found
eggs and more nesting grounds. Horner’s discoveries
show that some dinosaurs were cared for by their
parents, instead of having to fend for themselves as
soon as they hatched.
model of a
Maiasaura nest

14

Horner explains that hunting
for dinosaur fossils is not a
simple or exact science. It is not
just collecting and organizing
fossil bones. You have to look
carefully at the clues you collect.
Then you need to consider many
possibilities about how these
animals lived.
Men and women have been
hunting and collecting dinosaur
fossils for more than 200 years.
Yet they still don’t know the

The Archaeopteryx was
complete history of dinosaurs.
They know that these giants once both a bird and a reptile.
lived on each of the Earth’s
continents. They know what some of them looked
like and how they lived. But they don’t know exactly
why they suddenly became extinct.
Some scientists say we have only found and
collected a small number of the fossilized remains of
dinosaurs. We don’t know the full story yet. We have
to keep digging. There is still much work for fossil
detectives to do.

15


Vocabulary

Glossary
igneous rock

Extended Vocabulary

anatomy
luster
Cretaceous
anatomy
the scienceextinct
of the parts of living things
metamorphic rock

mineral
Jurassic
sediment
Cretaceous
a period ofpaleontology
time at the end of
sedimentary rock
protruding
the Mesozoic era that ended
quarry
66.4 million
years ago
extinct

no longer existing

Jurassic

a period of time in the middle of the
Mesozoic era when dinosaurs lived

paleontology

the science of studying fossils

protruding

sticking out from its surroundings

quarry

a place where stone is dug, cut,
or blasted out

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.
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

16

What did you learn?
1. How is a fossil formed?
2. What is Mary Anning famous
for discovering?
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.