Stanford to carbon-date molar donated by open-space district
The Midpeninsula Regional Open Space District announced the discovery Wednesday, identifying the molar as that of a Pacific mastodon, a large herbivore related to modern elephants. The animal was “most prominent in the American west including what is now California, Oregon, the northern Rocky Mountain region and parts of Mexico,” according to the district’s news release.
Lynch, who studies landforms and surface processes, was working at the preserve when she came across what initially appeared to be an unusual rock. Paleontologists subsequently confirmed the specimen as a Pacific mastodon molar, the district said. The tooth has been turned over to Stanford’s School of Sustainability, where geoscience researchers will apply carbon dating to refine the age estimate.
Wayne Thompson, the paleontologist who examined the specimen, said in a statement provided by the district that the tooth’s condition was exceptional. “The tooth itself is in immaculate condition,” Thompson said. “It’s the most complete mastodon molar from our area, and the most spectacular mastodon molar that I’ve ever seen. I had chills and shivers up and down my spine.” He described the find as “another puzzle in the Ice Age saga that we can put into place.”
Christine Garcia, a curator and manager of the geoscience specimen collection at Stanford, framed the fossil’s scientific value in broader terms. “Fossils are our only opportunity to see into past biodiversity,” Garcia said. “We can study fossils to better understand Earth’s past, past wildlife and the ecosystem they were a part of, and to help us make better predictions and better decisions about how to help our ecosystems and biodiversity thrive into the future.”
Pacific mastodons ranged across western North America for roughly 2.5 million years before disappearing more than 10,000 years ago. The district’s release attributes their extinction to the combined effects of climate-driven habitat change and hunting by humans.
Several other mastodon fossils have surfaced in recent years. In 2024, a New York state resident found a mastodon jaw beneath the surface of their lawn. A year earlier, in 2023, a woman discovered a foot-long ancient mastodon tooth protruding from sand on a beach near California’s central coast.