Fossil of Oldest Known Fur Seal Discovered

Posted on February 14, 2015

Scientists have discovered the fossil of the oldest known fur seal. The fossil was discovered in a 15-17 million year old rock formation in Southern California in 1980, but was misidentified as a walrus.

Robert Boessenecker from New Zealand's University of Otago came across the fossil in a collection at the John D. Cooper Archaeological and Paleontological Center. He realized it was not a small walrus fossil but the fossil of a tiny, early fur seal. Boessenecker and colleague Morgan Churchill from the University of Wyoming named the new genus and species of fur seal, Eotaria crypta. The genus name Eotaria stands for "dawn sea lion." The researchers say the ancient fur seal would have been about the size of a sea otter as an adult. The fossil discovery helps provide a missing link and fills a 5-million-year gap in fur seal and sea lion evolutionary history.

Boessenecker says in a statement, "This was very exciting as fur seals and sea lions--the family Otariidae--have a limited fossil record that, up until now, extended back to about 10-12 million years ago. Yet we know that their fossil record must go back to around 16-17 million years ago or so, because walruses--the closest modern relative of the otariids--have a record reaching back that far."

Boessenecker says the teeth of newly discovered species are an intermediate between the complex bear-like teeth of the earliest known pinnipeds and the more simplified teeth of modern sea lions.

A research paper on the new species is published here in the journal, Biology Letters.

ANIMALS