Posted: Monday, November 14, 2011
Although the walrus (Odobenus rosmarus) is one of the iconic mammals of the Arctic, its evolutionary story actually began in the tropics. By adapting to cold conditions, the distant ancestors of walruses were able to prosper in the harsh conditions of the northern polar regions. This took time; walruses are distantly related to fur seals and sea lions, but they have been on their own as a separate lineage for more than twenty million years. Although moderately diverse in the past, the walrus family declined over time and is now represented by just one species.