10,000-Year-Old Mastodon Tooth Found in San Mateo Creek

Paleontologists confirmed a tooth recovered by Brigid Lynch, a geomorphologist who studies landforms, from a San Mateo County creek bed is an adult Pacific mastodon molar — a chewing tooth — about 10,000 years old, the Midpeninsula Regional Open Space District announced. Immaculate, it provides a rare Ice Age record for the Bay Area.