What does cotype mean?
In biological classification, a cotype is a specimen that shares status with the holotype — the single specimen that serves as the definitive reference for a species' name. A cotype may be a duplicate prepared or collected from exactly the same material as the holotype, or one of several specimens that together formed the basis of the original species description. The term arises most often in older botanical and zoological literature, since modern nomenclatural codes favor sharper distinctions between syntypes (specimens cited jointly in the original description) and paratypes (additional specimens beyond the type). For researchers working with historical collections — herbarium sheets, insect drawers, museum skins — knowing whether a specimen is labelled a cotype matters, because such material carries particular weight in verifying identifications and resolving disputes about a species' identity. Though rarely encountered outside specialist circles, the word offers a neat illustration of how science refines its vocabulary: what was once a broad label has been replaced by more precise terms, leaving 'cotype' as a window into earlier taxonomic practice.
nounIn taxonomy, a cotype is a duplicate specimen of a type — one of two or more specimens on which a species description was originally based, or a duplicate made from the same material as the holotype.
- A taxonomic specimen that duplicates the holotype, made or collected at the same time and place, bearing equal standing as name-bearing material.
- (Historically) One of several specimens collectively serving as the type series when a species was originally described without a single designated holotype.
"The herbarium holds a cotype of the species, gathered by the original collector alongside the holotype."
"The botanist compared the new collection against a cotype housed in the Kew herbarium to confirm the identification."
"Because no holotype was fixed when the beetle was first described, each of the specimens in the original series was treated as a cotype."
As a countable noun referring to individual specimens, 'cotype' pluralizes normally; multiple specimens from a single original type series are often described collectively.
"The original description listed three cotypes among the type material deposited in Paris."
'Cotype' literally means 'same type' — it's the scientific world's way of saying two specimens are twins of a single named species.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cotype
The word 'cotype' combines the prefix 'co-' (from Latin, meaning together or jointly) with '-type', a suffix borrowed ultimately from Greek 'typos', meaning mark or impression. It emerged in nineteenth-century natural history, when collectors and museums needed a term for specimens duplicating or sharing type status with a holotype. Its sibling terms — genotype, phenotype, stereotype, prototype — all derive their endings from the same Greek root, which entered English largely through Latin.
How cotype is actually used
A technical term confined chiefly to taxonomy and natural-history literature; modern codes of nomenclature have largely replaced 'cotype' with more precisely defined terms such as syntype and paratype, so it now appears mostly in older descriptions.
Easily confused with cotype
A prototype is an original first model or version of something, whereas a cotype is a taxonomic specimen duplicate associated with the naming of a species.
A stereotype is either a printing plate or a fixed oversimplified belief, while a cotype refers to a botanical or zoological specimen linked to a species' original type material.