Editing Holotype

{{Short description|Example of an organism used to describe its species}}
{{Use dmy dates|date=March 2023}}
[[File:AgriasPhlacidonBertradiF2.JPG|thumb|Holotype with red type label affixed]]
[[File:Marocaster coronatus MHNT.PAL.2010.2.2 (Close up).jpg|thumb|Holotype of ''[[Marocaster coronatus]]'', [[MHNT]]]]
[[File:Movie of live Eupolybothrus cavernicolus Komerički and Stoev male holotype.webm|thumb|Live holotype of ''[[Eupolybothrus cavernicolus]]'']]
[[File:In situ video of Santjordia pagesi holotype specimen HD84GS1 (DLSI063) as recorded by remotely operated underwater vehicle Hyper-Dolphin.webm|thumb|thumbtime=2:54|Video of the capture of the holotype for the jellyfish species ''[[Santjordia|Santjordia pagesi]]'', as recorded by a [[remotely operated underwater vehicle]].]]

A '''holotype''' ([[Latin]]: ''holotypus'') is a single physical example (or illustration) of an [[organism]] used when the [[species]] (or lower-ranked [[taxon]]) was [[Species description|formally described]]. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the [[International Code of Zoological Nomenclature]] (ICZN), a holotype is one of several kinds of [[name-bearing type]]s. 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.

For example, the holotype for the butterfly ''[[Plebejus idas|Plebejus idas longinus]]'' is a preserved specimen of that subspecies, held by the [[Museum of Comparative Zoology]] at [[Harvard University]]. In [[botany]] and [[mycology]], an '''isotype''' is a duplicate of the holotype, generally pieces from the same individual plant or samples from the same genetic individual.

A holotype is not necessarily "typical" of that taxon, although ideally it is. Sometimes just a fragment of an organism is the holotype, particularly in the case of a [[fossil]]. For example, the holotype of [[Duriatitan|''Pelorosaurus humerocristatus'' (Duriatitan)]], a large [[herbivore|herbivorous]] dinosaur from the early [[Cretaceous]] period, is a fossil leg bone stored at the [[Natural History Museum, London|Natural History Museum]] in [[London]]. Even if a better specimen is subsequently found, the holotype is not superseded.

==Replacements for holotypes==
[[File:Encarsia accenta holotype slide.jpg|thumb|left|Modern holotype label for ''[[Encarsia|Encarsia accenta]]'']]

Under the ICN, an additional and clarifying type could be designated an ''epitype'' under article 9.8, where the original material is demonstrably ambiguous or insufficient.

A ''conserved type'' (ICN article 14.3) is sometimes used to correct a problem with a name which has been misapplied; this specimen replaces the original holotype.

In the absence of a holotype, another type may be selected, out of a range of different kinds of type, depending on the case, a [[lectotype]] or a [[neotype]].

For example, in both the ICN and the ICZN a neotype is a type that was later appointed in the absence of the original holotype. Additionally, under the ICZN the commission is empowered to replace a holotype with a neotype, when the holotype turns out to lack important diagnostic features needed to distinguish the species from its close relatives. For example, the crocodile-like [[archosaur]]ian reptile ''Parasuchus hislopi'' [[Richard Lydekker|Lydekker]], 1885 was described based on a [[premaxilla]]ry [[rostrum (anatomy)|rostrum]] (part of the snout), but this is no longer sufficient to distinguish ''Parasuchus'' from its close relatives. This made the name ''Parasuchus hislopi'' a ''[[nomen dubium]]''. Indian-American paleontologist [[Sankar Chatterjee]] proposed that a new [[type specimen]], a complete skeleton, be designated.<ref>Case 3165, [http://www.iczn.org/BZNMar2001cases.htm ''Bulletin of Zoological Nomenclature'' 58:1] {{webarchive|url=https://web.archive.org/web/20070928063845/http://www.iczn.org/BZNMar2001cases.htm |date=2007-09-28 }}, 30 March 2001.</ref> The [[International Commission on Zoological Nomenclature]] considered the case and agreed to replace the original type specimen with the proposed neotype.<ref>Opinion 2045, [http://www.iczn.org/BZNJune2003opinions.htm ''Bulletin of Zoological Nomenclature'' 60:2] {{webarchive|url=https://web.archive.org/web/20070928063853/http://www.iczn.org/BZNJune2003opinions.htm |date=2007-09-28 }}, 30 June 2003.</ref>

The procedures for the designation of a new type specimen when the original is lost come into play for some recent, high-profile [[species description]]s in which the specimen designated as the holotype was a living individual that was allowed to remain in the wild (e.g. a new species of capuchin monkey, genus ''[[Cebus]]'',<ref>Mendes Pontes, A.R., Malta A. and Asfora, P.H. 2006. A new species of capuchin monkey, genus ''Cebus'' Erxleben (Cebidae, Primates): found at the very brink of extinction in the Pernambuco Endemism Centre. Zootaxa 1200: 1–12.</ref> the bee species ''[[Marleyimyia xylocopae]]'', or the [[Arunachal macaque]] ''Macaca munzala''<ref>Sinha, A.,Datta, A., Madhusudan, M. D. and Mishra,  C.  (2004). "The Arunachal macaque ''Macaca munzala'': a new species from western Arunachal Pradesh, northeastern India". [[International Journal of Primatology]] volume: 26 issue: 977 pages: 989.</ref>). In such a case, there is no actual type specimen available for study, and the possibility exists that—should there be any perceived ambiguity in the identity of the species—subsequent authors can invoke various clauses in the ICZN Code that allow for the designation of a neotype. Article 75.3.7 of the ICZN<ref>{{Cite web|url=https://www.iczn.org/the-code/the-code-online/?article=75&nfv=|title=The Code Online &#124; International Commission on Zoological Nomenclature|website=www.iczn.org}}</ref> requires that the designation of a neotype must be accompanied by "a statement that the neotype is, or immediately upon publication has become, the property of a recognized scientific or educational institution, cited by name, that maintains a research collection, with proper facilities for preserving name-bearing types, and that makes them accessible for study", but there is no such requirement for a holotype.

==See also==
* [[Allotype (nomenclature)|Allotype]] (zoology)
* [[Genetypes]]—genetic sequence data from type specimens
* [[Paratype]]
* [[Type (biology)]]
* [[Type species]]

==References==
{{Reflist}}

==External links==
*{{Commons category-inline|Holotypes}}
*[http://www.butterfliesofamerica.com/L/Neotropical.htm BOA] Photographs of type specimens of Neotropical Rhopalocera.

{{Authority control}}

[[Category:Zoological nomenclature]]
[[Category:Botanical nomenclature]]