Type species
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In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature (naming) of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species to which the name of a genus is permanently linked. This is an important concept whenever a taxon containing multiple species must be divided into more than one genus; the type species automatically assigns the name of the original taxon to one of the resulting new taxa, thus reducing the potential for confusion.
Under both the zoological and botanical nomenclature codes, every named genus or subdivision of a genus, whether or not currently recognized as valid or correct, should have a type species. In practice however there is a backlog of untypified names.
A similar concept is used for supregeneric groups, the concept of a type genus.
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[edit] In zoology
The term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name-bearing type of the name of a genus or subgenus (a "genus-group name") is the "type species". In the Glossary, type species is defined as
- "The nominal species that is the name-bearing type of a nominal genus or subgenus".
The type species permanently attaches a genus to its formal name (its generic name) by providing just one species within that genus to which the genus is permanently linked (i.e. the genus must include that species if it is to bear the name). The species name in turn is fixed, in theory, to a type specimen.
For example, the type species for the land snail genus Monacha is Monacha cartusiana. That genus is currently placed within the family Hygromiidae. The type genus for that family is the genus Hygromia.
The concept of the type species in zoology was introduced by Pierre André Latreille.[1]
[edit] In botany
In botanical nomenclature, the type for any given taxonomic name - if it has a type - is technically a specimen (or illustration).[2] In the case of the name of a genus (or of a subdivision of a genus), its type will usually be the type for a species included within it and can be indicated by the name of this species alone.[3]
In modern nomenclature, the type of a genus (often referred to as the generitype) is systematically that of a published species (although that specific name might be currently regarded as a synonym), and thus only a species name is cited. As a result, despite the provisions of the code, it is not unusual to designate a genus' type without regard as to whether that species itself has a type (be in an holotype, lectotype or neotype). The term "type species", although of no formal standing under the Code (beyond performing an operation a code allows), has thus been borrowed from zoological nomenclature.
[edit] See also
[edit] References
- ^ Claude Dupuis (1974). "Pierre André Latreille (1762–1833): the foremost entomologist of his time" (PDF). Annual Review of Entomology 19: 1–14. doi:10.1146/annurev.en.19.010174.000245. http://www.annualreviews.org/doi/pdf/10.1146/annurev.en.19.010174.000245.
- ^ ICBN, articles 10.1, 8.1 and 10.4 (Vienna Code, 2005)
- ^ ICBN Art 10.1 (Vienna Code, 2005)
