Sometimes, slowly, the wind and rain wash away the layers of rock covering the fossil, leaving it lying on the surface of the ground. Other times hammers, shovels and other tools must be used to dig the fossil out of the rock. People interested in fossils, called paleontologists, collect the fossils and study them to learn about the plants and animals which lived long, long ago.

trilobite

ammonite

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Many of the plants and animals which lived in the past were very different from those which are living now. In rocks which formed on the ocean floor, squidlike animals called ammonites and buglike trilobites are commonly found as fossils. These animals are now extinct, meaning that none of them are still alive today.

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