Researchers have discovered new evidence indicating that humans may have existed in the Americas thousands of years earlier than previously assumed, a report published Thursday in the academic journal Science shows.
The discovery of ancient fossilized footprints in New Mexico's White Sands National Park revealed proof that humans inhabited in North America during the Last Glacial Maximum, which occurred between 21,000 and 23,000 years ago.
"This study illustrates the process of science - new evidence can shift long-held paradigms," U.S. Geological Survey acting Rocky Mountain director Allison Shipp said in a statement Thursday.
The widely believed view is that people came to North America from Asia around 13,000 to 16,000 years ago via Beringia, a land bridge that previously connected the two continents.
Researchers from White Sands National Park, the National Park Service, the U.S. Geological Survey, the University of Arizona, Bournemouth University, and Cornell University examined multiple footprint surfaces discovered buried between layers of gypsum soil on a dry lake in the park, which has the country's largest gypsum dune field.
In the study, archeologists utilized radiocarbon dating - a method for establishing the age of organic material - to evaluate macroscopic seeds found among the fossils. The footprints have "good anatomical definition," with prominent heel impressions and toe pads.
The humans who left the imprints, largely teenagers and children, lived in New Mexico during the last Ice Age.
During the Last Glacial Maximum, between 19,000 and 26,000 years ago, two vast ice sheets covered the northern third of the continent and reached as far south as New York City, Cincinnati, and Des Moines, Iowa.
The ice and freezing weather would have rendered traveling between Asia and Alaska impossible at the time, implying that the people who left the footprints arrived considerably earlier.
However, scholars remarked how perplexing it was that no artifacts, such as stone tools, had been discovered in the area.
The team highlighted, however, that precisely dating the earliest individuals to come and reside in the Western Hemisphere is still "uncertain and contested."
"What we present here is evidence of a firm time and location when humans were present in North America," the report said.
