Researchers are reporting the discovery of 14,500-year-old stone tools and a mastodon tusk in a Florida river that is causing experts to rethink prior assumptions about migration routes used by the earliest Americans. The findings also show that humans settled the southeastern United States as much as 1,500 years earlier than generally believed.
The study is published online in the journal Science Advances.
The remains were found in a sinkhole 26 feet under Florida’s Aucilla River — an archaeological site called Page-Ladson that was first discovered in 1987 by former Navy seal diver Buddy Page on property owned by the Ladson family.
Original excavations turned up eight stone tools and a mastodon tusk bearing what looked like cut marks, but no one followed up on the find. However, when co-author Daniel Fisher, director of the University of Michigan Museum of Paleontology and professor in the Department of Earth and Environmental Sciences, took a second look, he concluded that the deep grooves running parallel in the tusk could only have been made by humans using stone tools.
“These grooves are clearly the result of human activity and, together with new radiocarbon dates, they indicate that humans were processing a mastodon carcass in what is now the southeastern United States much earlier than was generally accepted,” said Fisher, as reported by Phys.org.
Extensive radiocarbon dating shows the artifacts are 14,500 years old and therefore predate by 1,500 years the Clovis people who were thought to have been the first migrants to the Americas.
Because mastodons and other megafauna became extinct in the Americas by 12,500 years ago, the early date of the Page-Ladson artifacts suggests that the first settlers did not wipe them out as quickly as many experts have argued.
“Instead, the evidence from this site shows that humans and megafauna coexisted for at least 2,000 years,” Fisher said.
A fascinating question raised by the discovery is how these ancient hunters got to Florida.
Genetic evidence shows that the ancestors of the first Americans came from Asia, leading to the generally accepted view that humans crossed the Bering Strait by way of a land bridge that once connected eastern Russia and Alaska during the last ice age. Then, they are thought to have spread throughout the continent through a narrow corridor between the massive ice sheets that still covered much of the northern U.S. and Canada.
The monkey wrench in the Bering land bridge theory is that evidence now shows humans were in Florida some 500 years before the ice-free corridor opened up.
“There has been a lot of resistance to the idea that people could enter North America from anywhere other than the Bering Strait,” said Linda Scott Cummings, an archaeobotanist at the PaleoResearch Institute in Golden, Colorado, who was not involved in the study, in a report by Smithsonian Magazine. “It really thrills me to see that there is widespread interest in exploring the other possibilities.”