Ancient tools and bone found in Florida could help rewrite the story of the first Americans

Thousands of years ago, some of the first Americans knelt beside a pond in what is now Florida. Clutching sharp stone knives, they hacked at the tusk of a slain mastodon, slicing meat away from the long bone. Then, with their work completed, they got up and walked away, leaving behind some tools and the stripped carcass .

Centuries passed. Sea levels rose. The ancient site was submerged by layers of sediment, and then by a rising river. Wave after wave of human inhabitants came and went: hunters, farmers, explorers, colonizers, retirees from New York. Until, in 2012, a team of archaeologists descended into the river's murky depths to dig up the artifacts below.

The ancient tools and bone are 14,550 years old, they reported Friday in the journal Science Advances, making them the most ancient human remnants ever found in the southeastern United States. The researchers say the find is unequivocal proof that people were in Florida more than 1,000 years earlier than anyone had imagined — a discovery that could help rewrite the history of humans on the continent.