In taxonomy, a superseded combination is a scientific name that has been replaced by a new combination as a result of a species being moved to a new genus after the initial species description. The original name is called a "superseded combination", and the new name is called the "new combination" or "" ("")
Some but not all superseded combinations are basionyms, and some basionyms are not superseded combinations. In zoological nomenclature, the superseded combination is not the same as a synonym and technically should not be called that.
If the species is moved again to a third genus, both of the older names are considered superseded combinations. The original name is the superseded original combination and the second name is the superseded recombination. If the species were moved back to a previous genus, the International Commission on Zoological Nomenclature would not consider the current name to be a new combination.
The specific epithet is kept in all these name changes, with perhaps some modification of the suffix to harmonize with the genus name.
For example, in 1766 Peter Simon Pallas described a new species of marine polychaete worm he called Aphrodita flava.Pallas, P.S. (1766) Miscellanea zoologica. Quibus novae imprimis atque obscurae animalium species describuntur et observationibus iconibusque illustrantur. Petrum van Cleef. Hagí Comitum., xii + 224 pp.;14 pls., available online at https://archive.org/details/pspallasmedicina00pall page(s): 97, plate 8, figures 7-11; note: Indian Ocean (2 locations) In 1867, that name became a superseded (original) combination when Hjalmar Kinberg moved the species to Thesmia, creating the new combination Thesmia flava.Kinberg, Johan Gustaf Hjalmar. (1867). Om Amphinomernas systematik. Öfversigt af Kongliga Vetenskaps-Akademiens Förhandlingar, Stockholm. 24(3): 83-91., available online at https://biodiversitylibrary.org/page/32326623 page(s): 86 The genus Thesmia was later synonymized with Chloeia,Read, G.; Fauchald, K. (ed.) (2024). World Polychaeta Database. Thesmia Kinberg, 1867. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=326050 on 2024-07-08 creating a new combination of Chloeia flava.Read, G.; Fauchald, K. (ed.) (2024). World Polychaeta Database. Chloeia flava (Pallas, 1766). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=209687 on 2024-07-08 Aphrodita flava is the superseded original combination, Thesmia flava is the superseded subsequent recombination, and the current name Chloeia flava is the new combination.
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