Fossils are produced over millions of years as sedimentary rocks form in layers around dead animals, plants and insects. A solid imprint forms on the rocks and that is the fossil. Fossils are extremely old. Fossils of creatures known as ammonites are thought to have lived between 408 and 66 million years ago.
People who study fossils are paleontologists. They can ascertain, by studying the number of layers surrounding the fossil, exactly when the animal was alive, or when the plant lived etc. In some cases bones are preserved in a fossil, but mostly minerals from the rocks filled the gaps that the plant or animal made when it decayed.
Generally, plants can only become fossils if they were buried in soil and then flattened quickly, otherwise they would decay before the fossil imprint would be made.
Paleontologists usually think that the best fossils are those of shellfish, because they die in water they are fossilized before they decay.
People who study fossils are paleontologists. They can ascertain, by studying the number of layers surrounding the fossil, exactly when the animal was alive, or when the plant lived etc. In some cases bones are preserved in a fossil, but mostly minerals from the rocks filled the gaps that the plant or animal made when it decayed.
Generally, plants can only become fossils if they were buried in soil and then flattened quickly, otherwise they would decay before the fossil imprint would be made.
Paleontologists usually think that the best fossils are those of shellfish, because they die in water they are fossilized before they decay.
