Eared Seal Research Paper

Species and Origin:

Otariidae or eared seals one of the three groups of pinnipeds and are more known as sea lions or fur seals. The eared seal is adapted to live a semi-aquatic lifestyle, meaning they feed and migrate through water then breed and live on land or ice. They live in subpolar, temperate, and equatorial waters throughout the Pacific and Southern Oceans as well as the southern Indian and Atlantic Oceans. They are absent in the northern Atlantic Ocean.

They are called "eared seals" because of the little external ear flaps they have that distinguish them from the phocids.

The Otariidae, and the other two pinniped families, descended from a closely related ancestor of the modern bear or Ursidae. The Otariidae arose in the Miocene (15-17 million years ago) in the Pacific Ocean and became more diverse whilst spreading across the Southern Hemisphere where most species now reside.

The earliest fossil osariid was found in California, the Eotaria crypta was the first and is the oldest sea lion to date and is believed to have lived during the Miocene period in which it was hypothesized for Otariidaes to have risen. This is a recent discovery and filled the millions of years of evolutionary history for the eared seal. When the fossils were discovered in 1980, it was misidentified to be related to the walrus.
However through research Robert W. Boessenecker and Morgan Churchill were able to connect Eotaria crypta to the Otariidae. The Eotaria crypta was a small creature, no bigger than a sea otter and had to watch it's back from the Allodesmus, a much larger creature that may as well have viewed the Eotaria crytpa as prey. Fortunately the small creature didn't have to worry about being eaten by a megalodon.

Allodesmus and Eotaria crypta - prehistoric seals

Otariidaes have divided into two subfamilies, the Arctocephalinae and the Otariinae, their major distinction being the presence of thick underfur layer. Between these the sea lions and fur seals differ with sexual dimorphism (physical differences from female to male; ie: color, shape, size), fur seals having more of this as well as prey and foraging differences and physical differences such as their fur type.

The Juan Fernández Fur Seal:

The Juan Fernández (Arctocephalus philippii) fur seal was discovered in the 16th century by navigator Juan Fernández on what is now the Juan Fernández islands just off the coast of Chile.
These seals are the second smallest seal of the otariids, the Galápagos fur seal being the smallest. Soon after their discovery they became victim to sealers or seal hunters in the Maritime Fur Trade era, and were hunted to near extinction. A small population was rediscovered in the mid-20th century and was protected, helping it repopulate and flourish. It is estimated that about 10,000 animals now live on the islands and are a near threatened
species.

The seals have a husky muscled body, a long, slender and pointed snout and stubby foreflippers and hindflippers. They have a mane of long, coarse guard hairs from the top of their head to their shoulders. Males vary from dark browns to blacks and their coarse guard hairs can be tan or yellowish near the tips, they also have a more round nose and are longer. They range from 150-200 cm in length and weight about 146 kg.

The females are entirely brown and their coarse guard hairs can be yellow or tan at the tips like the males. Females also have less thickness at the chest, neck and shoulders compared to the males and are about 240 cm long and weight about 50 kg. The pups are born with black fur that will lighten within a few years.