The study of fossils is called _paleontology_ (Greek _palaios_, ancient;
_ontos_, a being; _logos_, word or discourse). Information gathered with
the help of paleontology has greatly increased the knowledge of ancient
plants and animals and of the world in which they lived.
Fossils represent the remains of such great numbers and various types of
organisms that paleontologists have found it helpful to establish four
main divisions within their science.