Type species

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Cygnus cygnus, the whooper swan, is the type species of the genus Cygnus. Cygnus cygnus EM1B8407 (33625656403) (2).jpg
Cygnus cygnus, the whooper swan, is the type species of the genus Cygnus .

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 (or specimens). [1] A similar concept is used for suprageneric groups and called a type genus. [2]


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 name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name with that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. [3]

In bacteriology, a type species is assigned for each genus. [4] Whether or not currently recognized as valid, every named genus or subgenus in zoology 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.

Use in zoology

A type species is both a concept and a practical system that is used in the classification and nomenclature (naming) of animals. The "type species" represents the reference species and thus "definition" for a particular genus name. 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, the one that includes the type species.

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"). In the Glossary, type species is defined as

The nominal species that is the name-bearing type of a nominal genus or subgenus. [5]

The type species permanently attaches a formal name (the generic name) to a genus by providing just one species within that genus to which the genus name 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 Helix cartusiana, the name under which the species was first described, known as Monacha cartusiana when placed in the genus Monacha. 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. [6]


The International Code of Zoological Nomenclature states that the original name (binomen) of the type species should always be cited. It gives an example in Article 67.1. Astacus marinusFabricius, 1775 was later designated as the type species of the genus Homarus, thus giving it the name Homarus marinus (Fabricius, 1775). However, the type species of Homarus should always be cited using its original name, i.e. Astacus marinusFabricius, 1775, even though that is a junior synonym of Cancer grammariusLinnaeus, 1758. [1]

Although the International Code of Nomenclature for algae, fungi, and plants does not contain the same explicit statement, examples make it clear that the original name is used, so that the "type species" of a genus name need not have a name within that genus. Thus in Article 10, Ex. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum , not as the type of the species name Elodes aegyptica. [3] (Elodes is not now considered distinct from Hypericum .)

See also

Related Research Articles

Genus is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

<span class="mw-page-title-main">International Code of Zoological Nomenclature</span> Code of scientific nomenclature for animals

The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the International Commission on Zoological Nomenclature. The rules principally regulate:

<span class="mw-page-title-main">Holotype</span> Example of an organism used to describe its species

A holotype is a single physical example of an organism used when the species was formally described. It is either the single such physical example or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept.

<span class="mw-page-title-main">Type (biology)</span> Specimen(s) to which a scientific name is formally attached

In biology, a type is a particular specimen of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage, a type was a taxon rather than a specimen.

<i>Homarus gammarus</i> Species of lobster

Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of 60 cm (24 in) and a mass of 6 kilograms (13 lb), and bears a conspicuous pair of claws. In life the lobsters are blue, only becoming "lobster red" on cooking. Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles.

<span class="mw-page-title-main">Type genus</span> Term in biological taxonomy

In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name.

<span class="mw-page-title-main">Botanical name</span> Scientific name for a plant, alga or fungus

A botanical name is a formal scientific name conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups ."

<span class="mw-page-title-main">Cape lobster</span> Species of crustacean

The Cape lobster, Homarinus capensis, is a species of small lobster that lives off the coast of South Africa, from Dassen Island to Haga Haga. Only a few dozen specimens are known, mostly regurgitated by reef-dwelling fish. It lives in rocky reefs, and is thought to lay large eggs that have a short larval phase, or that hatch directly as a juvenile. The species grows to a total length of 10 cm (3.9 in), and resembles a small European or American lobster; it was previously included in the same genus, Homarus, although it is not very closely related to those species, and is now considered to form a separate, monotypic genus – Homarinus. Its closest relatives are the genera Thymops and Thymopides.

<i>Nomen dubium</i> Doubtful name in taxonomy

In binomial nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application.

In biological nomenclature, a syntype is any one of two or more biological types that is listed in a description of a taxon where no holotype was designated. Precise definitions of this and related terms for types have been established as part of the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants.

In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon or infraspecies. A "taxon", plural "taxa", is a group of organisms to be given a particular name. The scientific names of botanical taxa are regulated by the International Code of Nomenclature for algae, fungi, and plants (ICN). This specifies a three part name for infraspecific taxa, plus a connecting term to indicate the rank of the name. An example of such a name is Astrophytum myriostigma subvar. glabrum, the name of a subvariety of the species Astrophytum myriostigma.

In biology, a homonym is a name for a taxon that is identical in spelling to another such name, that belongs to a different taxon.

In botanical nomenclature, autonyms are automatically created names, as regulated by the International Code of Nomenclature for algae, fungi, and plants that are created for certain subdivisions of genera and species, those that include the type of the genus or species. An autonym might not be mentioned in the publication that creates it as a side-effect. Autonyms "repeat unaltered" the genus name or species epithet of the taxon being subdivided, and no other name for that same subdivision is validly published. For example, Rubus subgenus Eubatus is not validly published, and the subgenus is known as Rubus subgen. Rubus.

<span class="mw-page-title-main">Paratype</span> Taxonomic term

In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype. Often there is more than one paratype. Paratypes are usually held in museum research collections.

The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently.

<span class="mw-page-title-main">Taxonomic rank</span> Level in a taxonomic hierarchy

In biology, taxonomic rank is the relative level of a group of organisms in an ancestral or hereditary hierarchy. A common system of biological classification (taxonomy) consists of species, genus, family, order, class, phylum, kingdom, and domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics.

In zoology, the principle of coordination is one of the guiding principles of the International Code of Zoological Nomenclature.

Under the International Code of Zoological Nomenclature (Code), the name-bearing type is the biological type that determines the application of a name. Each animal taxon regulated by the Code at least potentially has a name-bearing type. The name-bearing type can be either a type genus, type species, or one or more type specimens. For example, the name Mabuya maculata has often been used for the Noronha skink, but because the name-bearing type of the former, a lizard preserved in the Muséum national d'histoire naturelle in Paris, does not represent the same species as the Noronha skink, the name maculata cannot be used for the latter.

In zoological nomenclature, emendations are intentional alterations made to the spelling of taxon names. In bacteriological nomenclature, emendations are made to the circumscription of a taxon.

<span class="mw-page-title-main">Glossary of scientific naming</span> List of terms and symbols used in scientific names for organisms, and in describing the names.

This is a list of terms and symbols used in scientific names for organisms, and in describing the names. For proper parts of the names themselves, see List of Latin and Greek words commonly used in systematic names. Note that many of the abbreviations are used with or without a stop.


  1. 1 2 "International Code of Zoological Nomenclature, Fourth Edition, adopted by the International Union of Biological Sciences". International Commission on Zoological Nomenclature. 1999. Article 67.1
  2. "Article 63. Name-bearing types". International Commission on Zoological Nomenclature. Retrieved 16 November 2023. The name-bearing type of a nominal family-group taxon is a nominal genus called the "type genus"; the family-group name is based upon that of the type genus
  3. 1 2 International Code of Nomenclature for algae, fungi, and plants (ICN) articles 7 through 10 (Melbourne Code, 2012)
  4. "Chapter 3: Rules of Nomenclature with Recommendations; Section 4. Nomenclatural Types and Their Designation", International Code of Nomenclature of Bacteria: Bacteriological Code, 1990 Revision, ASM Press, 1992
  5. ICZN Code Glossary
  6. Claude Dupuis (1974). "Pierre André Latreille (1762–1833): the foremost entomologist of his time". Annual Review of Entomology . 19: 1–14. doi:10.1146/annurev.en.19.010174.000245.