binomial system of nomenclature

In biology, the system in which all organisms are identified by a two-part Latinized name. Devised by the biologist Linnaeus, it is also known as the Linnaean system. The first name is capitalized and identifies the genus; the second identifies the species within that genus, for example the bear genus Ursus includes Ursus arctos, the grizzly bear, and Ursus maritimus, the polar bear.

Usually the names are descriptive. Thus, the name of the dog, Canis familiaris, means the ‘familiar species of the dog genus’, Canis being Latin for ‘dog’. Each species is defined by an officially designated type specimen housed at a particular museum. The rules for naming organisms in this way are specified in a number of International Codes of Taxonomic Nomenclature administered by two International Commissions on Nomenclature, one zoological and one botanical.

See also classification.