Enaliarctos barnesi

fossil mammal

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June 17, 2026

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Enaliarctos barnesi is an extinct species of mammal that represents the oldest known member of Pinnipedia, the group that includes modern seals, sea lions, and walruses. This species lived during the late Oligocene Epoch, approximately 29 million years ago, in the marine communities off the coast of North America.1

Enaliarctos had hind limbs specialized as flippers, enabling strong swimming abilities. Unlike modern seals, they could also use their hind limbs for movement on land, similar to sea lions. These early pinnipeds were fish predators and are classified within the order Carnivora, which also includes bears and cats. The evolution of pinnipeds like Enaliarctos was influenced by changes in ocean circulation that increased marine productivity.1

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Enaliarctos
The oldest of the five, E. barnesi and E. tedfordi, were found in rocks of the Yaquina Formation of Oregon that could be as old as 29.3 million years. A third species called E. mealsi, which is also the best-known of the group, is known from rocks in central California…
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The oldest of the five, E. barnesi and E. tedfordi, were found in rocks of the Yaquina Formation of Oregon that could be as old as 29.3 million years. A third species called E. mealsi, which is also the best-known of the group, is known from rocks in central California…
Read More