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(s). [1] A similar concept is used for suprageneric groups and 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 name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name that has 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. [2]

In bacteriology, a type species is assigned for each genus. [3]

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.

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. [4]

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. [5]


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. [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. [2] (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 biology. 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.

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:

Holotype The example of an organism used to describe its species

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, 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.

<i>International Code of Nomenclature for algae, fungi, and plants</i> Code of scientific nomenclature

The International Code of Nomenclature for algae, fungi, and plants (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". It was formerly called the International Code of Botanical Nomenclature (ICBN); the name was changed at the International Botanical Congress in Melbourne in July 2011 as part of the Melbourne Code which replaced the Vienna Code of 2005.

Type (biology) 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 attached. In other words, a type is an example that serves to anchor or centralize the defining features of that particular taxon. In older usage, a type was a taxon rather than a specimen.

Type genus

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

Botanical name 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 ."

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.

Nomenclature codes or codes of nomenclature are the various rulebooks that govern biological taxonomic nomenclature, each in their own broad field of organisms. To an end-user who only deals with names of species, with some awareness that species are assignable to families, it may not be noticeable that there is more than one code, but beyond this basic level these are rather different in the way they work.

In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon. 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 zoological nomenclature, the valid name of a taxon is the sole correct scientific name. The valid name should be used for that taxon, instead of any other name that may currently be being used, or may previously have been used. A name is valid when, and only when, it is in harmony with all the relevant rules listed in the International Code of Zoological Nomenclature (ICZN). A valid name is the correct zoological name of a taxon.

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.

A conserved name or nomen conservandum is a scientific name that has specific nomenclatural protection. That is, the name is retained, even though it violates one or more rules which would otherwise prevent it from being legitimate. Nomen conservandum is a Latin term, meaning "a name to be conserved". The terms are often used interchangeably, such as by the International Code of Nomenclature for Algae, Fungi, and Plants (ICN), while the International Code of Zoological Nomenclature favours the term "conserved name".

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.


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. In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies. This name is no longer in use: it is now a synonym of the current scientific name, Picea abies. In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination, rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refer to a taxon at that rank - for example, the name Papilio prorsaLinnaeus, 1758 is a junior synonym of Papilio levanaLinnaeus, 1758, being names for different seasonal forms of the species now referred to as Araschnia levana(Linnaeus, 1758), the map butterfly. However, Araschnia levana is not a synonym of Papilio levana in the taxonomic sense employed by the Zoological code.

In zoological nomenclature, an available name is a scientific name for a taxon of animals that has been published conforming to all the mandatory provisions of the International Code of Zoological Nomenclature for the establishment of a zoological name.

Taxonomic rank Level in a taxonomic hierarchy

In biological classification, taxonomic rank is the relative level of a group of organisms in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc.

In zoology, the Principle of Coordination is one of the guiding principles of the International Code of Zoological Nomenclature.

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. 1 2 International Code of Nomenclature for algae, fungi, and plants (ICN) articles 7 through 10 (Melbourne Code, 2012)
  3. "Chapter 3: Rules of Nomenclature with Recommendations; Section 4. Nomenclatural Types and Their Designation", International Code of Nomenclature of Bacteria: Bacteriological Code, 1990 Revision
  4. ICZN Code Glossary
  5. 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.