True Seals Lack Visible Ears

Unlike sea lions, true seals are completely earless. They lack external ear flaps, possessing only small openings on their heads that stay closed while swimming to stay streamlined.

While they are often called crawling seals, these animals are masters of underwater movement despite their clunky appearance on land. Because they lack external ear flaps, their heads look perfectly smooth and aerodynamic in the water. Interestingly, one species, the Baikal seal, actually lives entirely in freshwater lakes rather than the ocean. This group of seals has evolved a unique body plan that makes them the true athletes of the polar seas.