Practical: When a biological species is named a single specimen is designated to carry the name. It is a standard of reference and if the species is already described or two species are merged types are maintained in case of dispute. This single specimen is the holotype. Other types are recognized: lectotype is the most significant.
Official: A term used in previous editions of the Code for a holotype, lectotype or neotype, or for any syntype; also used generally for any specimen of the type series. (From the Glossary of the International Code of Zoological Nomenclature).
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