The primary economic importance of paleontology lies in the use of fossils to determine the age and nature of the rocks that contain them or the layers above or below. This information is vital to the mining industries and especially the petroleum industry. Simply looking at the fossils contained in a rock remains one of the fastest and most accurate means of telling how old that rock is.

Fossils were known by primitive man and were sometimes identified correctly as the remains of ancient lifeforms. The organized study of paleontology dates from the late 18th century.