A nomen oblitum (Plural: nomina oblita;
In its present meaning, the nomen oblitum came into being with the fourth, 1999, edition of the available name must be declared to be a nomen protectum; from then on, it takes precedence.
An example is the case of the scientific name for the leopard shark. Despite the name Mustelis felis being the senior synonym, an error in recording the dates of publication resulted in the widespread use of Triakis semifasciata as the leopard shark's scientific name. After this long-standing error was discovered, T. semifasciata was made the valid name (as a nomen protectum) and Mustelis felis was declared invalid (as a nomen oblitum).
Use in taxonomy
The designation nomen oblitum has been used relatively frequently to keep the priority of old, sometimes disused names, and, controversially, often without establishing that a name actually meets the criteria for the designation. Some taxonomists have regarded the failure to properly establish the nomen oblitum designation as a way to avoid doing taxonomic research or to retain a preferred name regardless of priority. When discussing the taxonomy of North American birds, Rea (1983) stated that "...Swainson's [older but disused] name must stand unless it can be demonstrated conclusively to be a nomen oblitum (a game some taxonomists play to avoid their supposed fundamental principle, priority)."
Banks and Browning (1995) responded directly to Rea's strict application of ICZN rules for determining nomena oblita, stating: "We believe that the fundamental obligation of taxonomists is to promote stability, and that the principle of priority is but one way in which this can be effected. We see no stability in resurrecting a name of uncertain basis that has been used in several different ways to replace a name that has been used uniformly for most of a century."
- ICZN 1999 (International Code of Zoological Nomenclature, 1999 Ed.) - http://www.nhm.ac.uk/hosted-sites/iczn/code/
- Pietsch, T.W.; Orr, J.W.; Eschmeyer, W.N. (2012). "Mustelus felis Ayres, 1854, a Senior Synonym of the Leopard Shark, Triakis semifasciata Girard, 1855 (Carchariniformes: Triakidae), Invalidated by "Reversal of Precedence"". Copeia 2012: 98–99.
- REA, A.M. (1983). Once A River. Tucson: University of Arizona Press.
- Banks, R.C., & Browning, M.R. (1995). "Comments on the status of revived old names for some North American birds." The Auk, 112(3): 633-648.