Physeter Macrocephalus Linnaeus, 1758, the valid name for the sperm whale

No uniformity exists in the use of the scientific name for the Sperm Whale, one of the earliest known and most familiar of the whale species. Both the names Physeter macrocephalus Linnaeus, 1758, and Physeter catodon Linnaeus, 1758, have been widely used for it. Hershkovitz (1966: 116120) in his check-list of the Cetacea listed 18 references (1758-1964) to the specific epithet catodon (an epithet that he accepted himself) and 24 references (1758-1957) to macrocephalus; as only the most important literature was cited by Hershkovitz, the usage of both epithets is far greater. In view of the lack of uniformity in the usage of the scientific name of the Sperm Whale, it is essential that its valid name be established. Of the two names, which were published simultaneously by Linnaeus (1758: 76) in the 10th edition of his Systema Naturae, Physeter macrocephalus unequivocally refers to the Sperm Whale and no doubt has ever been attached to the identity of that species. Linnaeus's description and references given under Physeter catodon, however, are rather obscure and for a long time were not well understood. Therefore the epithet macrocephalus before 1911 was used for the Sperm Whale by practically all authors. In that same period the epithet catodon was thought to refer either to (a) a distinct species, (b) a juvenile of Physeter macrocephalus, or (c) Delphinapterus leucas (Pallas, 1776); but before 1911 it was never adopted for the Sperm Whale, not even by those authors who thought P. catodon to be a juvenile of P. macrocephalus. In 1911 Thomas (1911: 157), who at that time was one of the foremost authorities on mammalian systematics, decided that P. catodon and P. macrocephalus were definitely synonymous and he accepted the name P. catodon for the species, as that name had line priority over P. macrocephalus. Thomas