Extremely rare Ice Age relic from massive extinct creature dating back more than 10,000 years is found in California creek
A geomorphologist surveying a San Mateo County creek in California this summer found what she initially thought was an oddly shaped rock, which paleontologists have since confirmed is an intact adult Pacific mastodon molar dating back at least 10,000 years. The find, announced by the Midpeninsula Regional Open Space District, is being hailed by experts as exceptionally rare and could deepen understanding of the Pacific mastodon, a species only formally recognised in 2019 that remains poorly understood.
Brigid Lynch, a geomorphologist with Balance Hydrologics, spotted the tooth in June while conducting field surveys for a project protecting the threatened California red-legged frog. Wayne Thompson of Pacific Paleontology described it as the most complete and spectacular mastodon molar he had ever seen from the region. Pacific mastodons, elephant-like browsers distinct from grass-eating mammoths, roamed the West Coast during the Pleistocene epoch until their extinction roughly 11,700 years ago. The tooth was donated in July to Stanford University's Doerr School of Sustainability, where researchers plan to carbon-date it and create a 3D-printed replica for public education.
- Rare 10,000-year-old Pacific mastodon molar found in California creek
- Discovered by chance during frog conservation fieldwork in June
- Tooth donated to Stanford for carbon dating and study
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Ice Age creatures once roamed what is now the west coast of the United States, and California's fossil record occasionally turns up traces of them. Mastodons were large, elephant-like mammals related to but distinct from mammoths, browsing on trees and shrubs rather than grazing on grass, before dying out roughly 11,700 years ago. The Pacific mastodon, a specific West Coast species, was only formally identified by scientists in 2019 and is still not well understood.
Fossil finds of this kind are uncommon, and discoveries are often made by chance rather than through dedicated digs. Researchers typically rely on institutions such as universities to examine, date and preserve such specimens once they surface, since accurately identifying an ancient bone or tooth requires specialist expertise.