Sea Lions, courtesy of Laskeek Bay Conservation Society
Harbor Seal, courtesy of Jessie Huggins
Steller Sea Lions, courtesy of NOAA
Pinniped refers to the group of marine mammals that have front and rear flippers and includes seals and sea lions. These animals live in the ocean but are able to come on land for long periods of time.
Earless seals (or true seals) can easily be identified by looking at their ears and flippers. They have ear holes but no external ear flaps. They also have small front flippers and move on land by flopping along on their bellies. At sea, true seals move their rear flippers back and forth like a fish’s tail to propel themselves through the water.
Another family of pinnipeds which includes sea lions are referred to as eared seals. Unlike true seals, they have external ear flaps. Their front flippers are large, and on land they are able to bring all four flippers underneath their bodies and walk on them. In the water, they swim using their front flippers like oars.