odobenids

Odobenids, or the walrus family Odobenidae, are a small group of pinnipeds that includes the living walrus (Odobenus rosmarus) and several extinct taxa. The only living genus is Odobenus, with two widely recognized subspecies: the Pacific walrus (Odobenus rosmarus divergens) and the Atlantic walrus (Odobenus rosmarus rosmarus). Modern odobenids inhabit Arctic and subarctic seas of the North Pacific and North Atlantic, relying on sea ice for resting, social activity, and breeding.

Walruses are among the largest pinnipeds. Adults show marked sexual dimorphism, with males larger than females. They are distinguished by long upper tusks, which are elongated canines, prominent vibrissae (whiskers) for sensing prey, a thick blubber layer, and broad foreflippers that aid movement on land and ice. Their coloration ranges from dark brown to gray, often appearing lighter with age or after shedding.

Ecology and feeding in benthic environments are central to odobenids. They forage mainly for mollusks, such as clams, on the seafloor and use suction feeding to extract soft tissues. Tusks assist in manipulating prey, social display, and hauling themselves out onto ice or shores. Walruses are highly social and form large groups on ice floes or beaches. Reproduction takes place in late winter to spring, with females birthing a single calf after a long gestation and lactation period; calving intervals are typically about two years, and males compete for access to harems.

The fossil record shows a once-diverse Odobenidae across the North Pacific and Arctic from the Miocene onward. Today’s walrus is the sole surviving member of the family, and climate-driven loss of sea ice remains the primary conservation concern. The IUCN lists the walrus as vulnerable.