Type Definitions

Unsure of any scientific type definitions? Then take a look through our list of types and related terms

Making Sense of Type Specimens

Dragonfly Linnaean Coll Type

Do you know your 'neotype' from your 'holotype'? Many of the specimen collections we hold (both Carl Linnaeus's and James Edward Smith's) are type specimens studied by scientists from all over the world.

Our specimen collections include plants, insects, shells and fish, and are accessible globally online, with all of their label information. (Note: examples listed in these definitions are botanical.) Here is your alphabetical guide to decoding it.

Authority

The name of the author (abbreviated following Brummitt & Powell 1992), appended to the binomial name which he or she published, e.g. Lotus mauritanicus L., "L." indicating Linnaeus. Where two author names appear, as in Indigofera mauritanica "(L.) Thunb.", this is an indication that Thunberg transferred an earlier name (Lotus mauritanicus), described by the author in parenthesis (Linnaeus), to a different genus (Indigofera).

Autonym

A name established automatically. For example, the publication of Lotus corniculatus var. tenuifolius L. (1753) automatically created Lotus corniculatus L. var. corniculatus to accommodate the "typical" part of the species (see Art. 6.8), even though this varietal name does not appear in Species Plantarum.

Basionym

A previously published legitimate name or epithet-bringing synonym from which a new name is formed. Lotus mauritanicus L. is the basionym of Indigofera mauritanica (L.) Thunb.

Binomial

The name of a species, composed of two parts in Latin: the name of the genus followed by a single species (specific) name (or epithet), e.g. Lichen caperatus L.

Cytotype

Where a species displays significant variation in its chromosome numbers or structures, these different forms may be termed cytotypes. In species such as these, it may be important to establish the cytotype to which the type specimen belongs, in order to apply infraspecific names correctly.

Diagnosis

A short phrase, or polynomial, usually in Latin for Linnaean names, giving the characters by which the author believes the taxon can be distinguished. Also known as a diagnostic phrase name, or nomen specificum legitimum.

Epithet

A single word, usually applied to a species, which when appended to the name of a genus, forms a binomial.

Epitype

A specimen or illustration selected to serve as an interpretative type when the identity of the primary type (e.g. the lectotype) cannot be precisely established.

Generitype

The type of the name of a genus (which is the type of the name of a species). For purposes of designation or citation of a type, the species name alone suffices, i.e. it is considered as the full equivalent of its type (Art. 10.1).

Heterotypic synonym

A synonym based on a type different from that of the accepted name.

Homonym

A name spelled exactly like another name published for a taxon of the same rank and based on a different type. The later of two such names will be illegitimate.

Homotypic synonym

A synonym based on the same type as that of another name at the same rank.

IBC

International Botanical Congress.

ICBN

International Code of Botanical Nomenclature.

Iconotype

Sometimes used to indicate an illustration that serves as a type.

Iso-

Indicating a duplicate, hence isolectotype, isoneotype.

Isotype

A duplicate of a holotype.

L.

Authority abbreviation for Linnaeus.

Lectotype

A specimen or illustration designated from the original material as the nomenclatural type when no holotype was indicated.

Monospecific

Of a genus, which contains only a single species.

Monotypic

See monospecific.

Neotype

A specimen or illustration selected to serve as a nomenclatural type when all of the material upon which the name was based is missing.

Nomenclatural type

See type.

Nomen specificum legitimum

See diagnosis.

Nomen ambiguum/nomina ambigua

A name(s) whose application is uncertain or unknown.

Original material

Those specimens and illustrations from which a lectotype can be chosen.

Phrase name

See diagnosis.

Protologue

Everything associated with a name at its valid publication, i.e. description or diagnosis, illustrations, references, synonymy, geographical data, citation of specimens, discussion and comments.

Rank

Any position in a taxonomic hierarchy – order, family, genus, species and variety are examples of different ranks.

Single gathering

Several specimens collected simultaneously.

Superfluous name

A name applied to a taxon circumscribed by its author to include the type of an earlier name (the name of which ought to have been adopted).

Syntype

Any specimen cited in the protologue when no holotype was designated, or any of two or more specimens simultaneously designated as types (Art. 9.4).

Taxon

A taxonomic group at any rank.

Topotype

Any collection of a taxon made at its type locality.

Type

A specimen or illustration to which the name of a taxon is permanently attached.

Type method

Establishing the correct application of names through the use of types.

Typotype

Herbarium material from which a type illustration was prepared.

Typus

Latin for type.

Voucher specimen

Herbarium material believed to be associated with an illustration, or a specimen preserved when a part of it is used for more detailed study (e.g. micromorphological, chemical, cytological, molecular).