The question of when humans first migrated to North America has long been a matter of hot debate among researchers who have continually uncovered evidence of ever-earlier dates. Now, analysis of ancient fossilized human footprints in New Mexico has pushed the date back once again — to at least 21,000 years ago.
Writing in the journal Science, a team of researchers led by Matthew Bennett of Bournemouth University in England examined a set of human footprints preserved on an ancient lakeshore in New Mexico's White Sands National Park, a location now known for its expansive — and dry — chalk-colored dunes.
They concluded that the footprints were made between 21,000 and 23,000 years ago. The date would place human habitation in the Americas during the Last Glacial Maximum and at least 5,000 years earlier than widely accepted evidence has yet suggested.
The footprints were mostly made by children and teenagers
Bennett and his colleagues, whose paper was published Thursday, determined that the tracks belonged to numerous people, mostly children and teenagers. What's more, the footprints spanned a significant time period, suggesting that humans frequented the area for at least a few thousand years.
"One of the beautiful things about footprints is that, unlike stone tools or bones, they can't be moved up or down the stratigraphy," Bennett says, according to Science News, referring to the layers where artifacts and fossils are found. "They're fixed, and they're very precise."