Scientists studying the habitat of an endangered frog species in San Mateo County, California, noticed an unusually shaped object in a streambed. What initially appeared to be a stone turned out to be a mastodon tooth dating back approximately 10,000 years.
Scientists studying the habitat of an endangered frog species in San Mateo County, California, noticed an unusually shaped object in a streambed. What initially appeared to be a stone turned out to be a mastodon tooth dating back approximately 10,000 years.