The word fossil comes from the Latin word fossillis, which means digging. Fossil is the main research object of paleontology, which provides evidence for studying the life history of animals and plants in geological period. The records of fossils in ancient books in China, such as Ji Ran in the Spring and Autumn Period and Wujin in the Three Kingdoms Period, all mentioned the bones and teeth of vertebrate paleontology in Shanxi.
In the long geological age, countless creatures lived on the earth, and many of their dead bodies or traces left by life were buried by the sediment at that time. In the following years, the organic matter in these biological remains was completely decomposed, and the hard parts such as shells, bones, branches and leaves were petrified into stones with the surrounding sediments, but their original shapes and structures (even some subtle internal structures) remained.