Both male and female sea lions have a pointy, whiskered nose and long, narrow muzzle. Young pups are almost dog-like in profile. Another characteristic that defines the sea lion is the pinnae of the external ears, which distinguish them from seals. The foreflippers have a short fur extending from the wrist to the middle of the dorsal fin surface, but other than that, the flippers are covered in black, leathery skin. Curving posteriorly, the first digit of the flipper is the largest, giving it a swept-back look. At the end of each digit is a claw, usually reduced to a vestigial nodule that rarely emerges above the skin. Although clumsy on land, sea lions are agile in water. With their streamlined bodies and flipper-like feet, they easily propel themselves through crashing surf and sharp coastal rocks. They also have the ability to control their flippers independently and thus change directions with ease.