The fossil of an ancient woolly mammoth's tusk has been discovered near a dairy farm in Tulare County.

According to Roger LaJeunesse, anthropology professor at California State University, the 10-foot-long tusk is estimated to be 100,000 years old.

The tusk was the only evidence found of the ancestor of the Asian elephant. The area of the discovery was once the site where two prehistoric rivers converged and archaeologists have recovered the bones of mammoths, saber-tooth cats, giant sloths, camels, and prehistoric horses.

Earlier in the week, scientists confirmed fossilized bones and a tusk found in Silicon Valley were likely those of a Columbian mammoth that roamed the area, between 10,000 and 40,000 years ago.

Dairyman Joey Airoso found the tusk and gave a chip of it to his daughter, a college student, who took it to the anthropology department at Fresno States.