Brigid Lynch, a scientist who studies the Earth’s surface, was walking through a preserve in the Midpeninsula Regional Open Space District (Midpen) in San Mateo County when she came across an important find: a giant Ice Age tooth. Lynch was working in a stream bed on a field study for the threatened California red-legged frog when he saw the “oddly shaped rock” in the water. Paleontologists later confirmed it was a molar from an adult Pacific mastodon, a huge herbivore that resembled an elephant and roamed the Earth for 2.5 million years before becoming extinct about 11,000 years ago. “As a geologist, I’ve gone out and seen things in the field, but definitely nothing as exciting as this,” Lynch said in a news release. The name mastodon, which is formed from two Greek words meaning “breast” and “tooth,” refers to the animal’s molars, which are described as nipple-shaped protuberances, according to the American Museum of Natural History. Mastodons differ from woolly mammoths in their head shape and their diet, which went beyond grass and included twigs, leaves and fruits. Scientists only differentiated the Pacific mastodon from the American mastodon in 2019, based on its thicker leg bones and narrower teeth. Paleontologist Wayne Thompson, owner of Pacific Paleontology, said in the news release that the tooth is “another puzzle in the Ice Age saga that we can solve.” “The tooth itself is in perfect condition. It’s the most complete mastodon molar in our area and the most spectacular mastodon molar I’ve ever seen,” Thompson said. “I felt chills and chills ran down my spine.” Following the discovery, the Midpeninsula Regional Open Space District donated the tooth to Stanford University’s Doerr School of Sustainability, where scientists will determine its age. Later, the researchers plan to 3D print copies of the tooth for educational use. “Fossils are our only chance to see the biodiversity of the past,” Christine Garcia, curator and manager of the Geosciences Specimen Collection at Stanford University, said in the news release. “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 in the future.”
