The naming systems used in various branches of science are called nomenclature .
Most branches have strict rules about the naming of organisms or celestial bodies or compounds.
Paleontology is the study of life of the geologic past, including analysis of plant and animal fossils. According to the rules of paleontology, the name given the first fossils of a previously unknown species becomes the name of the species. The name of one well-known dinosaur species has had an interesting history. In 1892 paleontologist Edward Cope discovered remains of a dinosaur. The 1902 discovery of a more complete dinosaur fossil led to the species name Tyrannosaurus rex.