(abbreviation nom. cons., plural nomina conservanda – latin for "a name to be preserved") A nomen conservandum is a name that, under strict application of the appropriate code of nomenclature, should be invalid, but which the relevant commision has decided should be upheld in the interests of stability and communication. This may, for instance, involve the preservation of a well-known name for a taxon rather than its otherwise mandatory replacement with an unfamiliar or poorly-defined senior synonym. To what extent a name is conserved depends on the case - a name can be universally conserved, so that it takes priority over any non-conserved synonym, whether already known or recognised later, or it may only be conserved relative to the specific name(s) recognised in competition at the time.
For instance, the name Meganthropus africanus was established for a fossil hominid by Weinert in 1950. Later, this was synonymised with Australopithecus afarensis Johanson et al., 1978 within the genus Australopithecus. As there is already an Australopithecus africanus Dart, 1925, A. afarensis was the correct name. However, some authors have suggested that Australopithecus afarensis should be removed from Australopithecus and placed in the genus Praeanthropus. As the homonymy with Australopithecus africanus would then be removed, the technically correct name for the species would then be Praeanthropus africanus (Weinert, 1950). However, a request was made to the International Commission on Zoological Nomenclature for the preservation of the species name afarensis (nomen conservandum) due to its high public profile, and to prevent confusion with the equally well-known Australopithecus africanus. The ICZN upheld this request in 1999, meaning that even when placed in a different genus, Australopithecus afarensis remains afarensis.