Under the ''

International Code of Zoological Nomenclature 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 I ...

'' (''Code''), the name-bearing type is the

biological type In biology, a type is a particular specimen (or in some cases a group of specimens) 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 centralizes the ...

that determines the application of a name. Each animal

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

regulated by the ''Code'' at least potentially has a name-bearing type.''Code'', Article 61.1 The name-bearing type can be either a

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...

(

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

group),''Code'', Article 63

type species 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 specim ...

(

genus Genus ( plural genera ) 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 nom ...

group),''Code'', Article 67.1 or one or more

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) 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 centralizes th ...

s (

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

group).''Code'', Article 72.1.2 For example, the name ''Mabuya maculata'' (Gray, 1839) has often been used for the Noronha skink (currently ''Trachylepis atlantica''), but because the name-bearing type of the former, a lizard preserved in the

Muséum national d'histoire naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loc ...

in Paris, does not represent the same species as the Noronha skink, the name ''maculata'' cannot be used for the latter.

Effect on synonymy

Under the ''ICZN'', two names of the same rank that have the same name-bearing type are objective synonyms, as are two whose name-bearing types are themselves objectively synonymous names;''Code'', Glossary, "objective synonym" for example, the names ''Didelphis brevicaudata'' Erxleben, 1777, and ''Didelphys brachyuros'' Schreber, 1778, were both based on a specimen (now in the

British Museum of Natural History The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum ...

) described by Seba in 1734 and are therefore objective synonyms (the species they refer to, a small South American opossum, is currently known as ''

Monodelphis brevicaudata The northern red-sided opossum or the Guianan short-tailed opossum, ''Monodelphis brevicaudata'', is an opossum species from South America. It is found in Bolivia, Brazil. French Guiana, Guyana, Suriname and Venezuela. Characteristics Body len ...

''). In contrast, a subjective synonym is based on a different name-bearing type, but is regarded as representing the same taxon;''Code'', Glossary, "subjective synonym"; Article 61.3.1 for example, the name ''Viverra touan'' Shaw, 1800, is based on a different name-bearing type (a specimen in the

Field Museum of Natural History The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational ...

), but is currently regarded as representing the same species as ''Didelphis brevicaudata'' and ''Didelphys brachyuros''.

Family group

"Family-group" ranks include the

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

and all other ranks below it and above the

, including the

and

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...

.''Code'', Article 35.1 The name of a family-group taxon is based on the stem of a designated

;''Code'', Article 63 for example, the Central American rodent tribe Nyctomyini has '' Nyctomys'' as its type genus and its name consists of the stem of the type genus, Nyctomy-, and the appropriate ending for a tribe, -ini.

Genus group

"Genus group" ranks consist of the

and

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between ...

.''Code'', Article 42.1 The name-bearing type for a genus-group taxon is the

, which must be one of the species included when that taxon ("genus" hereafter for brevity) was first formally named''Code'', Article 67.2 or, when no species were included when the genus was named, one of the first species that were subsequently included in it.''Code'', Article 67.2.2 A genus described after 1930 (1999 for

ichnotaxa An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

) must have its type species fixed when first named;''Code'', Article 67.4 in taxa described earlier without such an explicit designation, the type species can be fixed subsequently.''Code'', Article 69.1 For example, the

skink Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. ...

genus ''Euprepis'' contained nine species when first described by Wagler in 1830, but no type species was designated. In 2002, Mausfeld and others used the name for a mainly African group of skinks, designating ''Lacerta punctata'' Linnaeus, 1758, as the type species (currently ''

Lygosoma punctatum ''Lygosoma'' is a genus of lizards, commonly known as supple skinks or writhing skinks, which are members of the family Scincidae. ''Lygosoma'' is the type genus of the subfamily Lygosominae. The common name, writhing skinks, refers to the way ...

''), but in 2003, Bauer noted that Loveridge had already fixed the type species of ''Euprepis'' in 1957 as ''Scincus agilis'' (currently ''

Mabuya agilis ''Mabuya'' is a genus of long-tailed skinks restricted to species from various Caribbean islands. They are primarily carnivorous, though many are omnivorous. The genus is viviparous, having a highly evolved placenta that resembles that of eutheri ...

''), invalidating the later fixation by Mausfeld and others. Accordingly, ''Euprepis'' is now a subjective synonym of ''

Mabuya ''Mabuya'' is a genus of long-tailed skinks restricted to species from various Caribbean islands. They are primarily carnivorous, though many are omnivorous. The genus is viviparous, having a highly evolved placenta that resembles that of eutheri ...

'' and the mostly African group Mausfeld and others incorrectly called ''Euprepis'' is known as ''

Trachylepis ''Trachylepis'' is a skink genus in the subfamily Mabuyinae found mainly in Africa. Its members were formerly included in the " wastebin taxon" ''Mabuya'', and for some time in ''Euprepis''. As defined today, ''Trachylepis'' contains the clade ...

''.

Species group

Official "species-group" ranks consist of just the

and

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

.''Code'', Article 45.1 (Note: a ''species group'' defined as a taxon, rather than as a category of ranks, has an unofficial rank, one of several such ranks between the subgenus and species levels sometimes used by zoologists in taxa with many species; see

Taxonomic rank In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family, order, class, phylum, kingdom, domain. While ...

.) The name-bearing type of a species-group taxon (hereafter "species" for brevity) is an actual specimen or set of specimens; the ''Code'' recommends that great care should be exercised to ensure the preservation of such specimens. It can either be designated in the publication establishing the name or designated later. In the former case, there is either a single name-bearing type, a

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

,''Code'', Article 73.1 or a set of

syntype 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 ...

s. In species named before 2000 without explicit designation of a holotype, all specimens in the

type series In biology, a type is a particular specimen (or in some cases a group of specimens) 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 centralizes the ...

are considered as syntypes.''Code'', Article 73.2 Name-bearing types designated after the original publication include lectotypes and

neotype In biology, a type is a particular specimen (or in some cases a group of specimens) 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 centralizes the ...

s. If a taxon has syntypes, one of those can be selected as the lectotype,''Code'', Article 74.1 upon which act the others lose the status of syntype.''Code'', Article 73.2.2 A neotype may be designated to replace the previous name-bearing type when the original type is lost or by application to the Commission when the previous name-bearing type cannot be identified.''Code'', Article 75 For example, Shaw's name ''Viverra touan'' was based on a description of "Le Touan" by

Georges-Louis Leclerc, Comte de Buffon Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste. His works influenced the next two generations of naturalists, including two prominent ...

, which left the identity of the name uncertain, and in 2001 Voss and others selected as the neotype a specimen in the

, which thereby becomes the name-bearing type. Sittardus Scyllarides latus

The name-bearing type is usually an individual animal in a museum collection; for example, the name-bearing type (in this case, lectotype) of the skink species currently known as ''

Trachylepis maculata ''Trachylepis maculata'', the spotted mabuya, is a species of skink in the genus '' Trachylepis'' recorded from Demerara in Guyana, northern South America. It is placed in the genus '' Trachylepis'', which is otherwise mostly restricted to Afri ...

'' (Gray, 1839) is a lizard preserved in the collections of the French Muséum national d'histoire naturelle.Miralles et al., 2009, fig. 7, p. 62 Other kinds of name-bearing types are also allowed by the ''Code'', including colonies of asexually reproducing animals, natural casts of fossils, a series of stages of the life cycle of a living protistan (a

hapantotype In biology, a type is a particular specimen (or in some cases a group of specimens) 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 centralizes the ...

), and some others.''Code'', Article 72.5 If an illustration or description is used as the basis of a species, the specimen or group of specimens illustrated or described is the name-bearing type (not the illustration or description itself), even if no longer in existence.''Code'', Articles 72.5.1, 73.4.1

Notes

:''References to ''"Code"'' refer to the International Code for Zoological Nomenclature (International Commission on Zoological Nomenclature, 1999).''

Literature cited

*Bauer, A.M. 2003. "On the identity of ''Lacerta punctata'' (Linnaeus 1758), the type species of the genus ''Euprepis'' (Wagler 1830), and the generic assignment of Afro-Malagasy skinks." ''African Journal of Herpetology'' 52:1–7. *Groves, C.P. 2005. "Order Primates." Pp. 111–184 in Wilson, D.E. & Reeder, D.M. (eds.).
Mammal Species of the World: a taxonomic and geographic reference
3rd ed.'' Baltimore: Johns Hopkins University Press, 2 vols., 2142 pp. *Holthuis, L.B. 1996.
Original watercolours donated by Cornelius Sittardus to Conrad Gesner, and published by Gesner in his (1558–1670) works on aquatic animals
. ''Zoologische Mededelingen'' 70:169–196. *International Commission on Zoological Nomenclature. 1999.
International Code of Zoological Nomenclature, 4th ed.
' London: International Trust for Zoological Nomenclature. *Mausfeld, P. and Vrcibradic, D. 2002.
On the nomenclature of the skink (''Mabuya'') endemic to the western Atlantic archipelago of Fernando de Noronha, Brazil
' (subscription only). ''Journal of Herpetology'' 36(2):292–295. *Miralles, A., Chaparro, J.C. and Harvey, M.B. 2009.
Three rare and enigmatic South American skinks
(first page only). ''Zootaxa'' 2012:47–68. *Musser, G.G. and Carleton, M.D. 2005. "Superfamily Muroidea." Pp. 894–1531 in Wilson, D.E. and Reeder, D.M. (eds.). "
Mammal Species of the World: a taxonomic and geographic reference
3rd ed." Baltimore: Johns Hopkins University Press, 2 vols., 2142 pp. {{ISBN, 978-0-8018-8221-0 *Voss, R.S., Lunde, D.P. and Simmons, N.B. 2001.
The mammals of Paracou, French Guiana: a Neotropical lowland rainforest fauna. Part 2. Nonvolant species
" ''Bulletin of the American Museum of Natural Histor''y 263:1–236. Zoological nomenclature