It all flies in the face of what has long been believed about how humans came to North America—the dominant theory being that humans used the Bering land bridge connecting Siberia and Asia to North America during the Ice Age, and moved south as ice melted and exposed routes of exploration. During the southward migration, scientists believe people left behind various fluted stone projectile points (known as a Clovis point, as the people group considered the first to come to the Americas were named for a town in Clovis, New Mexico).

Lowery tells the Washington Post that he found what he believed was a Clovis point—something he had seen on a Smithsonian television program—around his home near Parsons Island, Maryland as a 9-year-old. That piqued his interest in the region, and he has been focused on the 78-acre, privately owned island ever since.

Lowery and other geologists got permission to study the island from the owners, and have used 93 visits to the site for excavation and studying sediment to help determine the dating of the geological layers. What is now coastline wasn’t always, and the team believes they may have found a pond that helped attract both animals and people to the site, leaving behind the stone tools now in question.

Sebastien Lacombe, an archaeologist at Binghamton University, tells the Washington Post that the rapid erosion of the island is likely pushing artifacts deep into the waters of the bay, meaning we’ve likely already lost much of our opportunity to scour the site for additional finds.

From fresh research in New Mexico to the Parsons Island details, the updated perspectives don’t allow for the tidy history-book account of the Ice Age bridge from Siberia to be the full explanation of how we found our way to North America—if correct.

But that “if correct” remains the sticking point—some scientists claim that the dating techniques of these “pre-Clovis” sites aren’t reliable, and others believe in the dating techniques but simply don’t agree with anything that doesn’t conform to the Clovis theory. Still others are willing to discuss the intriguing find, even if questions remain. “The case is not as tight as we like to see it with other sites,” Steven Forman, a geoscientist at Baylor University who helped date the sediment layers at Parsons Island, told the Washington Post.

With so many of the artifacts now moving from their original location due to erosion, the “bulletproof geological context” is hard to find. But that won’t stop experts from looking, or from debating what they find.