Davy Villanueva hoped the fish would be biting when he went out to the San Antonio River a few weeks ago, but he never imagined he’d see a tooth bigger than the size of his two fists.

The Karnes City, Texas, fisherman found what he believes is a tooth from a mastodon, the big-tusked behemoths that roamed North America as far back as 3.75 million years ago, according to Illinois State Museums. The mammoth-related beasts became extinct 11,000 years ago.

Villanueva told KENS 5 TV in San Antonio that the recent drought had lowered river levels so much that he found the tooth in about a foot of water.

“I walked in the river and reached down in there and pulled it out, and wow, I have never seen anything like this,” Villanueva told the local station.

Villanueva won’t reveal exactly where he found the pronged tooth — not even to his wife, Patty Cruz. He thinks there may be more remains at the spot, but recent rains have raised water levels too high to explore further.