Sea Lion Evolution

California Sea Lion Taxonomy

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pinnipedia

Family: Otariidae

Genus: Zalophus

Species: Californianus 

Evolution

Within the scientific community, there are several theories behind where the sea lion originated from, and until this day its origin is somewhat of a mystery. Scientific evidence suggests that pinnipeds evolved from a bear-like creature millions of years ago. Pinnipeds are spilt into three different families; eared seals, true seals, and walruses. Pinnipeds have bodies that are well adapted to their aquatic habitats and are known for their wide wing-like flippers.Their sleek bodies are perfect for diving and swimming and often stay submerged under water for up to a half hour. The California Sea lion belongs to the Otariidae family and is thought to have shown up about 10-12 million years ago in the North Pacific. The sea lions family name Otariidae comes from the Greek word Otarion which means "little ear". The sea lions external ear flaps and its distinguished dog-like head shape are the only things that make it distinguishable from the true seals. The earliest sea lions were believed to be much smaller, about the size of a modern day otter, and spent the majority of their time on land. "Eared seals" such as the sea lion are better adapted to terrestrial habitats and have an easier time moving around on all fours. The sea lions large layer of blubber is what regulates its body temperature in the cold ocean water. 

Sources

http://www.newworldencyclopedia.org/entry/Eared_seal

http://sealion-world.com/sea-lion-evolution.html