Bears, comprising the family Ursidae, are widespread carnivoran mammals found across North America, South America, and Eurasia, typically recognized by their large bodies, stocky legs, and plantigrade paws with five nonretractable claws. While the polar bear is mostly carnivorous and the giant panda mostly herbivorous, the other six species are omnivores; these generally solitary animals are surprisingly adept runners, climbers, and swimmers, and most species hibernate in dens for up to 100 days each winter. Historically, bears have been hunted since prehistoric times for meat and fur, exploited in harsh entertainment like bear-baiting, and have played a prominent role in human art, mythology, and culture. Today, the IUCN lists six of the eight species as vulnerable or endangered, facing threats from habitat loss and illegal trade in bear parts, particularly the Asian bile market, while even least-concern species like the brown bear face local extirpation. The English word "bear" itself originated as a taboo euphemism meaning "the brown one" or "wild animal" in Germanic tongues, while fossil evidence shows the earliest ancestors, such as Parictis, were small, raccoon-like creatures living roughly 38 million years ago.