Sea lions are related to walruses and seals. Together with the fur seals, they constitute the family Otariidae, collectively known as eared seals. Until recently, sea lions were grouped under a single subfamily called Otariinae, whereas fur seals were grouped in the subfamily Arcocephalinae. This division was based on the most prominent common feature shared by the fur seals and absent in the sea lions, namely the dense underfur characteristic of the former. Recent genetic evidence, suggests "Callorhinus", the genus of the northern fur seal, is more closely related to some sea lion species than to the other fur seal genus, "Arctocephalus". Therefore, the fur seal/sea lion subfamily distinction has been eliminated from many taxonomies.