A field survey in San Mateo County led to the discovery of an intact adult Pacific mastodon molar, a fossil researchers believe is about 10,000 years old.
Brigid Lynch, a geomorphologist with Balance Hydrologics, was conducting research for the Midpeninsula Open Space Preserve related to the threatened California red-legged frog when she encountered what appeared to be an unusually shaped rock. After an image search suggested it could be a mastodon tooth, Midpen contacted paleontologist Wayne Thompson of Pacific Paleontology for an assessment. Thompson confirmed the identification.
Midpen has not released the fossil’s precise location. The preserve said it was found in redwood forests in the Santa Cruz Mountains portion of San Mateo County. Thompson, who has worked as a paleontologist for five decades, said the tooth is unusually well preserved.
Mastodon teeth commonly break apart, he said, while this specimen is mostly intact, indicating that the animal’s skull may be close to where the molar was found.
Mastodons disappeared roughly 11,700 years ago. Researchers say the animals once occupied regions that include present-day California, Oregon, the northern Rocky Mountain area and parts of Mexico. Thompson also said Ice Age fossils are increasingly being exposed, including at construction locations that are subject to environmental protections.
