Odobenidae

Odobenidae is a family of pinnipeds that includes the walrus and its extinct relatives. It is one of the three extant pinniped families, alongside Otariidae (eared seals) and Phocidae (true seals). The only living genus in the family is Odobenus, represented today by a single species, Odobenus rosmarus, commonly known as the walrus. There are two widely recognized subspecies: the Pacific walrus (Odobenus rosmarus divergens) and the Atlantic walrus (Odobenus rosmarus rosmarus). The fossil record shows that odobenids once comprised a broader and more diverse group, with several extinct genera such as Dusignathus, Imagotaria, and Paleodobenus known from Miocene to Pliocene deposits in the North Pacific and adjacent regions.

Walruses are large, aquatic mammals characterized by prominent tusks— elongated canine teeth present in both sexes— that are used for defense, social display, and aiding in hauling themselves out onto ice. They have a thick blubber layer and a robust body, with sensitive vibrissae (whiskers) that help locate prey on the seafloor. Walruses are highly social and form large groups on sea ice and beaches. Their diet consists mainly of benthic invertebrates, especially clams and other mollusks, which they extract from the substrate using suction and scooping techniques.

Geographically, Odobenidae is circumpolar, inhabiting Arctic and subarctic seas where seasonal ice provides resting sites and access to prey. Reproduction is seasonal, and calves are nourished by extended lactation. Conservation concerns for walruses center on climate-driven loss of sea-ice habitat and increasing human activities in Arctic regions, including hunting and shipping. The group’s fossil record highlights a once richer evolutionary history, with ongoing research refining its taxonomy and paleobiology.