Footprints found in White Sands National Park in New Mexico provide the first unequivocal evidence of human activity in the Americas and offer a glimpse into life over 23,000 years ago.
The footprints were formed in the soft mud on the edges of a shallow lake that is now part of Alkali Flat, a large beach in White Sands. Researchers at the US Geological Survey dated these traces using radiocarbon dating of the seed layers above and below the horizons of the imprint. The dates vary in age and confirm human presence for at least two millennia, with the oldest traces dating to around 23,000 years, which corresponds to the height of the last glacial cycle, making them the oldest human footprints. known in the Americas.
The research, published in Science on September 24, was conducted by scientists from Cornell, the University of Bournemouth, the National Park Service, the US Geological Survey and the University of Arizona. The White Sands trails were first discovered by David Bustos, the park’s resource manager.
In order to study the site, the team developed non-invasive geophysical techniques led by Thomas Urban, a researcher at the College of Arts and Sciences and with the Cornell Tree Ring Laboratory.
“Detection and imaging with non-destructive technology has dramatically expanded our ability to study these remarkable fingerprints in their larger context,” said Urban. “Now we have a unique window into life during the Pleistocene in North America, and this new study provides the first unequivocal evidence of a sustained human presence in the Americas thousands of years earlier than most archaeologists. didn’t think so. “
Footprints tell an interesting story of life during this time, researchers say. Judging by their size, the tracks were left mostly by teenagers and younger children, sometimes with adults. Traces of animals – mammoth, giant ground sloth, large wolves and birds – are also present.
“This is an important site because all the tracks we found there show an interaction of humans in the landscape alongside extinct animals,” said co-author Sally Reynolds of the University of Bournemouth. “We can see the coexistence between humans and animals at the site as a whole, and by being able to accurately date these footprints, we build a better picture of the landscape.”
Traditional archeology relies on the discovery of bones and tools but can often be difficult to interpret. Human footprints provide unequivocal evidence of the presence and also of the behavior. It was previously thought that humans entered America more than 16,000 years ago, after the melting of North American ice caps, which opened up migration routes. However, the footprints show a much earlier migration of humans to the Americas.
“The footprints left at White Sands give a picture of what was going on, of teens interacting with younger children and adults,” said Matthew Bennett, of the University of Bournemouth, who helped lead the study. “We can think of our ancestors as being quite functional, hunting and surviving, but what we see here is also a play and gathering activity of different ages. A real glimpse of these first people.