History of the Polar Bear - Canadian Museum of Nature

Ursus maritimus

Polar bears probably diverged from brown bear ancestors near the Arctic coast of Eurasia early in the Ice Age. They may have evolved from coastal scavengers into active hunters of seals on sea ice. The oldest known fossil (nearly 70,000 years old) is from near Kew, England, and represents a bear much larger than those currently living.

Other fossils are from Hamburg, Germany, Yamal Peninsula (the former Soviet Union), and several sites in Sweden and Denmark. The species may have been known to Paleolithic artists, for what appear to be two polar bears are depicted on a wall in the cave of Ekain, near the northern coast of Spain.

Hence, polar bears appear to have decreased in size and retreated northward since the end of the last glaciation.

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