There are different marine mammals in the world oceans e.g. whales, dolphins, sea otters and seals. Seals are divided into 3 families, True seals (Phocidae), Walruses (Odobenidae) and Eared seals (Otariidae). There are a lot of differences between the families but the main ones are that the Walrus have large whiskers and tusks, Eared seals have external earflaps while the True seals only have a hole.
In the Eared seal family there are 2 subfamilies, the Fur seals and the Sea lions. Most of them look similar, and genetic wise they are closely related. The features to distinguish them from each other are that Fur seals have a much thicker fur then Sea lions. Sea lions are larger in size then Fur seals, while the sexual dimorphism (size difference between male and females) is larger in Fur seals then Sea lions. Sea lions have a longer nose with their eyes set futher back in their heads while Fur seals have a shorter nose with the eyes closer to the nose. The ear flaps on Fur seals are larger and sticking father out from the head then Sea lions, and their flipper are proportionally longer on Fur seals then Sea lions.
