Pinniped Pinniped Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 33 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora and their
Pinniped into two monophyletic subfamilies: Monachinae, which consists of "Mirounga", Monachini and Lobodontini; and Phocinae, which includes "Pusa", "Phoca", "Halichoerus", "Histriophoca", "Pagophilus", "Erignathus" and "Cystophora". In a 2012 review of pinniped taxonomy, Berta and Morgan Churchill suggested that, based on morphological and genetic criteria, there are 33 extant species and 29 subspecies of pinnipeds, although five of the latter lack sufficient support to be conclusively considered subspecies. They recommend that the genus "Arctocephalus" be limited to "Arctocephalus pusillus", and they resurrected the name "Arctophoca" for several species and subspecies formerly placed in "Arctocephalus". More than 50 fossil species have been described.