Nomenclature of Organisms

Nomenclature of Organisms

Every recognised species needs one, and only one, scientific name that is understood the same way anywhere in the world — this is the purpose of nomenclature.

Binomial nomenclature, introduced by Carl Linnaeus, gives every species a two-part Latinised name: the first word is the genus name (capitalised) and the second is the specific epithet (lower case), e.g. Panthera leo. Both parts are italicised or underlined in print.

Trinomial nomenclature extends this system by adding a third name to denote a subspecies — a geographically or morphologically distinct population within a species that is not yet considered a full species in its own right, e.g. Panthera tigris tigris (the Bengal tiger) as a subspecies of Panthera tigris. The trinomial format is: Genus + species + subspecies.

Tautonymy is the situation in which the genus name and the specific (or subspecific) epithet are identical, e.g. Naja naja (the Indian cobra) or Rattus rattus (the house rat). Tautonymous names are permitted under zoological rules but are explicitly not allowed in botanical nomenclature. …