Paleontologist Meredith Rivin of the John D. Cooper Archaeological and Paleontological Center in Fullerton, California, presented the finds Feb. 17 at the annual meeting of the American Association for the Advancement of Science.

 

“In California, you need a paleontologist and an archaeologist on-site” during such projects, Rivin says. That was fortuitous: The Laguna Canyon outcrop, excavated between 2000 and 2005, turned out to be a treasure trove containing hundreds of marine mammals that lived 17 million to 19 million years ago. It included 30 cetacean skulls as well as an abundance of other ocean dwellers such as sharks, says Rivin, who studies the fossil record of toothed baleen whales. Among those finds, she says, were four newly identified species of toothed baleen whale—a type of whale that scientists thought had gone extinct 5 million years earlier.