Scientists believe that Ursus maritimus, the "sea bear," evolved about 200,000 years ago from brown bear ancestors. Polar bears are the world's largest land predators. They top the food chain in the Arctic, where they dine primarily on seals. Polar bears are the largest land carnivore. Male polar bears, which are called boars, grow two to three times the size of female polar bears, which are called sows. Boars weigh about 350 to more than 650 kg that's 772 -1,433 pounds, and they are about 8 ½ to 10 feet long! Sows weigh about 300 to 600 pounds and are about 6.6 to 8.2 ft. long. Pregnant females can weigh as much as 1,102 pounds! The largest polar bear ever recorded was a male weighing 2,209 pounds and measuring and enormous 12 ft. long. Compared to other bears such as the brown and black bears, polar bears have elongated bodies and long slender necks. Mostly used for swimming in the water. Their heavy fur coat can be pure white to creamy yellow to light brown depending on the season and angle of light your looking at it.
Polar bears hind limbs are longer than the forelimbs. This makes the large, muscular hind end stand higher than the shoulders. Although both there hind and forelimbs are very large and stocky. They have huge paws compared to their body size, there feet can get up to a foot in diameter. The large paws of a polar bear act like snowshoes, spreading out the bear's weight as it moves over ice and snow. They have 5-toed paws and each toe has a thick, curved, non-retractable claw. The claws are used for grasping prey and for traction when running or climbing on ice. The sole of a polar bear's foot has thick, black pads covered with small, soft papillae or dermal bumps. The papillae create friction between the foot and ice to prevent slippage. Long hairs growing between pads and toes also help prevent slipping on the ice. A polar bear's head is relatively small compared to its body size; its muzzle is elongated with a slightly arched snout.