Fur seals and sea lions (Otariidae): Identification of species and taxonomic review

Abstract

Abstract The standard anatomical descriptions given to identify species of the family Otariidae (fur seals and sea lions), particularly those for the genus Arctocephalus, have been largely inconclusive. Specimens of some species conformed more to the description of others, overlapping in many identifying characteristics. Recent re‐examination of the genetic basis of taxonomic diversity within otariids required matching by comprehensive new studies of skull morphometry based on large sample sizes, to provide a sound basis for re‐appraisal of species limits in the family. The typical skull morphology of otariids fall into two general characteristics: a short, mesocephalic skull observed primarily in the fur seals and a more dolichocephalic skull common in most sea lions. Subfamily separation of otariid seals was not supported. Instead, a separation of genus, species and subspecies was proposed, with re‐arrangement of taxonomy at the levels of genus, species and subspecies. Arctocephalus australis, A. forsteri and A. galapagoensis appeared congeneric, with only subspecific differences in morphology. Arctocephalus townsendi and A. philippii appeared congeneric, yet were morphologically divergent from the remainingArctocephalus. Skulls of Zalophus californianusjaponicus were significantly different from those of Z. c. californianus and Z. c. wollebaeki, and were considered a separate species of Zalophus.