In biology, the type species is the species used to define a taxonomic group of higher rank, such as the genus or the family. From the characteristics of this species, the description and characterization of the group of species sharing these characteristics is established.
Strictly speaking, a "type species" exists only in zoological nomenclature. As specified in Article 42.3 of the ICZN (International Code of Zoological Nomenclature), the "type species" is the type of the name of a genus or subgenus. The glossary defines it as follows:
The species name, in turn, is attached to a type specimen or holotype. Ideally, any named genus or subgenus should have a type species, but in practice there is an accumulation of names without an assigned type.
In botany and mycology
In botanical nomenclature, the nomenclatural type is “the element to which the name of a taxon, whether correct or synonymous, is permanently attached. (Art 7.2 of the International Code of Botanical Nomenclature - CINB).
In botanical nomenclature, the type of a name, genus or otherwise, is a specimen (or illustration) (ICBN, Articles 10.1, 8.1 and 10.4). In the case of the name of a genus (or a subdivision of a genus) this type will usually be the type of a known species (art 10.1). This species is sometimes called informally "type species" but this designation has no formal character in botany.
Generally, only a species, or an infraspecific taxon, can have its own type. For new taxa (published after January 1, 1958) of these levels, a type can no longer be an illustration.
A genus (almost always) has the same type as one of the subordinate species. We can, for convenience, call it "type species", but this is not an official term. There is one exception: a genus can have its own type only by preservation (Art 10.4).
A family (or any subdivision of a family) has the same type as one of the subordinate genera (which is, almost always, the type of a species). We can, for convenience, call this genre the "typical genre", but it is not an official term.
A taxon of higher rank than family may share the type of one of the subordinate families, but only if its name is derived from that of that family (Magnoliales shares the type of family Magnoliaceae). Descriptive names (Angiospermae, Monocotyledones, Hepaticae, Fungi, etc.) do not have a nomenclatural type.
A list of nomenclatural types is provided in art 9 of the CINB, the most important of which is the holotype. It should be noted that the term “type” is used in the botanical literature in expressions without official value within the framework of the CINB: for example a clonotype.
(en) This article is partially or totally taken from the Wikipedia article in English entitled "Type species" (see the list of authors). All or part of this article is based on the Nomenclatural vocabulary of Guy Redeuilh (2002) , Valérie Malécot (2010) and Samantha Bazan (2015)
Notes and References
Nomenclatural type (zoological)
Nomenclatural type (botanical)
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