What is "type species"

n. (context biology taxonomy English) A species which has been designated as typical of a genus, and is chosen as the species according to which the genus is named.

n. (biology) the species that best exemplifies the essential characteristics of the genus to which it belongs

In zoological nomenclature, a type species (species typica) is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). A similar concept is used for suprageneric groups called a type genus.

In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus is a specimen (or, rarely, an illustration) which is also the type of a species. The species that has that type can also be referred to as the type of the genus. Genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types.

In bacteriology, a type species is assigned for each genus.

Every named genus or subgenus in zoology, whether or not currently recognized as valid, is theoretically associated with a type species. In practice, however, there is a backlog of untypified names defined in older publications when it was not required to specify a type.