Learning about prehistoric life

Scaly dinosaurs and flying reptiles disappeared from the earth about
sixty-five million years ago—long before there were people. Yet there
are pictures of these animals in books. How do we know what these
prehistoric animals looked like if no one ever saw a live dinosaur or a
flying reptile?

Scientists called paleontologists tell us what the plants and animals of
long ago were like. They examine fossils—the remains of plants and
animals left in stone and other places. These include fossil bones,
teeth, footprints, and leafprints. From such fossils, paleontologists
can tell a great deal about living things of the past—- how big they
were, what they looked like, how they walked, and even what food they
probably ate!

Where are fossils found? The search for fossils goes on just about
everywhere. Fossils have been uncovered on high mountaintops, under
layers of ice, in steep cliffs along rivers, and in coal mines. The
oldest fossils ever found are simple plants that lived more than three
billion years ago.

This paleontologist is looking at the fossil skeleton of a mammoth.