Experts confirmed in January that they likely were 17-million-year-old clam shells, barnacles and snail shells from the Miocene epoch, between 23 million and 5.3 million years ago. John Foster, coordinator of Cal State Fullerton’s John D. Cooper Archaeological and Paleontological Center, said Laguna Beach would have been hundreds of feet underwater millions of years ago and that the fossils likely came from shallower depths closer to where the shoreline would have been.
Source: latimes.com – Los Angeles Times