Pinniped Fossil: Enaliarctos mealsi
This fossil represents one of the earliest members of the group of animals that includes living seals, sea lions and walruses. Like its living relatives, this animal had flippers and was clearly at home in the water. But its bones also retain features of its land-living ancestors. Thus, it helps us understand this land-to-sea evolutionary transition. It was discovered, beautifully preserved and nearly complete, by an amateur paleontologist who donated it to the National Museum of Natural History so that it could be studied by scientists.
Photo by Michael Brett-Surman / Smithsonian Institution