Some 14,500 years ago, ancient Floridians were carrying sharpened tools, chopping up mastodon tusks (and probably eating their gooey ends), and might even have kept pet dogs, according to new evidence unearthed at an underwater archaeological dig—unique in North America—that has changed our understanding of how the continent was settled.
Based on radiocarbon dating of stone artifacts and mastodon remains, researchers say that the Page-Ladson site, which is on the Aucilla River near Tallahassee, is the oldest submerged archaeological site in the Americas, and one of the oldest on the continent.
In a new report in Science Advances, a team describes their four-year study of the site, which was once a pond. There, they found, hunter-gatherers butchered megafauna that roamed during that period. Alongside a dog's jaw bone, which suggests that dogs were living around the settlement, they found signs that humans and large mammals (like mastodons) probably co-existed in Florida for some 2,000 years before they went extinct, 12,600 years ago.
"The excavation was successful beyond our dreams," said Jessi Halligan, assistant professor of anthropology at Florida State University, in a media conference announcing the discoveries.
We now need to push back the timeline of the peopling of the Americas, scientists say. A sharpened blade was apparently used a thousand years before the time of the Clovis people—who were thought to be the first to settle in North America, based on other evidence from digs in New Mexico in the 1920s. The agreed-upon theory was that the Clovis used the land bridge between Alaska and Siberia to populate the American continents some 13,000 years ago. But it looks like another migration began closer to 16,000 years ago.
For a long time, the Page-Ladson site, which was originally discovered in the 1980s, wasn't given its due by most of the archeological community, as it did not necessarily align with agreed-upon human migration theories, according to these researchers.
"You were a complete quack if you thought there [were] pre-Clovis sites in the Americas," said Halligan. "You were clearly presenting flawed data in some way, shape or form, and I think over the ensuing 25, 30 years, that has started to slowly change."
This dig was always going to be challenging, these archeologists explained, which is one reason that it remained relatively unexplored for so long. "It's 30 feet under water," said Halligan. "The number of people who are specialists in prehistoric archeology and work underwater… There are less than ten of us across the entire continent."
What the archeologists were after was at the bottom of what's now a sinkhole in the Aucilla River, 26 feet deep. So they combined traditional land-based techniques with underwater methods, like the kind used for shipwreck sites. The river is very dark, and silt and dirt filter into it, so lights were required. The diving archeologists could only see what was in front of them.
"We were excavating very much like you would excavate a terrestrial site," said Halligan. "We would excavate with trowels like people on terrestrial archeological projects do," except they were wearing SCUBA gear and carrying other underwater equipment.
"If we could blow the water out of the Page-Ladson site and let you take a picture while you were excavating, it would look—except for the fact that we're ridiculous in wet suits—just like a traditional site," said Halligan.
Michael Waters, director of the Center for the Study of the First Americans at Texas A&M University, said that he feels there are more discoveries to be made at Page-Ladson, and wouldn't hesitate to go back.
"In the archeological community, there's still a terrific amount of resistance to the idea that people were here before Clovis," said Waters. "I think the beauty of the Page-Ladson site is that it provides everything people want to see. It adds to our growing knowledge of these people, now we know they've made it all the way to Florida."