Fossils

When you hear the word extinct, what comes to mind? You might think about giant dragonflies and fierce dinosaurs. Maybe you imagine ancient bones buried deep in the ground. You may have seen the bones of an extinct organism in a museum.

A species is extinct when there are no longer any living members of that species on Earth. Many different kinds of species have become extinct. In fact, most of the species that have existed on Earth are no longer around. Some extinct species you might have heard of include the woolly mammoth, the saber-tooth tiger, and the Tyrannosaurus rex. Each of these species once existed on Earth, but there are none of them around today.

Because there are no living members of extinct species on Earth, scientists must look for other clues to learn about these organisms. This is why many scientists study fossils. A fossil is any remains or trace of an organism that lived in the past. Fossils give scientists clues about species that are extinct.

There are many types of fossils. One type of fossil is fossilized bone. Every once in a while, scientists will find an entire fossilized skeleton. However, they usually find only parts of a skeleton.

Another type of fossil is an imprint. An imprint is a copy of the shape of an organism. Scientists have found imprints of leaves, plants, or animals in rocks. Organisms that lived long ago can also leave behind footprints. Footprints are a type of imprint fossil.

What do fossils tell us about extinct species? Scientists can get clues about the organism’s size, about how it moved, or about its shape. Fossilized footprints help scientists learn whether an animal was two-legged or four-legged. They can help scientists determine how fast the animal could move. Fossilized teeth give scientists clues about what an animal ate. Fossils tell us quite a bit about organisms that are now extinct!

These fossilized bones may be from humans that lived long ago.

This fossil is an imprint of a scallop shell in clay rock.

This fossilized dinosaur footprint gives scientists clues about how the animal moved.

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