A "killer walrus" thought to have terrorized the North Pacific 15 million years ago may not have been such a savvy slayer after all, researchers say.
A new analysis of fossil evidence of the prehistoric beast shows it was more of a fish-eater than an apex predator with a bone-crushing bite.
Traces of the middle Miocene walrus, named Pelagiarctos thomasi, were first found in the 1980s in the Sharktooth Hill bone bed of California. A chunk of a robust jawbone and sharp pointed teeth, which resembled those of the bone-cracking hyena, led researchers to believe the walrus ripped apart birds and other marine mammals in addition to the fish that modern walruses eat today.
But a more complete lower jaw and teeth from the long-gone species were recently discovered in the Topanga Canyon Formation near Los Angeles. Researchers say the shape of the teeth from this new specimen suggest the walrus was unlikely adapted to regularly feed on large prey. Instead, they think it was a generalist predator, feasting on fish, invertebrates and the occasional warm-blooded snack.