The footprints found in the White Sands National Park, in New Mexico, constitute the first unequivocal evidence of human activity in America and allow us to discover life more than 23,000 years ago. The findings are described in a Science journal article co-authored by University of Arizona archaeologist Vance Holliday.
For decades, archaeologists have debated when people first arrived in the Americas said Holliday, a professor in the School of Anthropology and the Department of Geosciences at the University of Arizona. Few archaeologists see reliable evidence of sites older than about 16,000 years. Some believe that the arrival was later, no more than 13,000 years ago, by the manufacturers of the so-called Clovis points. The White Sands footprints provide a much earlier date. There are multiple layers of well-dated human footprints in the stream beds where water flowed into an ancient lake. This was 10,000 years before the Clovis people.
Researchers Jeff Pigati and Kathleen Springer of the US Geological Survey used radiocarbon dating of the seed layers above and below the tracks to determine their age. The dates vary in age and confirm human presence over at least two millennia, with the oldest footprints dating back 23,000 years.
This corresponds to the height of the last glacial cycle, during the period known as the Last Glacial Maximum, and makes them the oldest known human footprints in the Americas.
Previously it was thought that humans entered the Americas much later, after the melting of the North American ice sheets, which opened migratory routes. Our seed dates are closely grouped and maintain stratigraphic order above and below multiple track horizons; this was a remarkable result , Springer said.
The footprints tell an interesting story of what life was like at that time. Judging by their size, the footprints were left primarily by teenagers and young children, with the occasional adult. The footprints left at White Sands offer a picture of what was going on, teenagers interacting with younger children and adults said study lead author Matthew Bennett of Bournemouth University in England. We might think that our ancestors were quite functional, hunting and surviving, but what we see here is also play activity, and of different ages gathering together. A true insight into these early people .
Holliday and study co-author Brendan Fenerty, a doctoral student at the University of Arizona in the Department of Geosciences, documented basic geological stratification and trench dating in the White Sands Missile Range , near the discovery site, several years before the footprints were found. We were interested in reconstructing the evolution of the landscape in the context of environmental changes and some younger archaeological sites in the area Holliday said. We had no idea what was buried nearby.
At the White Sands site there are also tracks of mammoths, giant ground sloths, wolves and birds. It is an important site because all the tracks we have found there show an interaction of humans in the landscape with extinct animals , like mammoths and giant sloths said study co-author Sally Reynolds of Bournemouth University. We can see the coexistence between humans and animals throughout the site, and by being able to accurately date these footprints, we are building a larger picture of the landscape .
The White Sands human footprints were first discovered by David Bustos, the park's director of resources. It is incredible to have confirmation of the age of the human footprints, and exciting but also sad to know that this is only a small part of the 80,000 acres in which the footprints have been revealed and that they are being rapidly lost to pollution. continuous soil erosion said Bustos.
The team also pioneered the use of non-invasive geophysical techniques to help locate the reservoir. Tommy Urban of Cornell University led this part of the work. Detection and imaging with non-destructive technology has greatly expanded our ability to study these remarkable footprints in their larger context he said.
Traditional archeology is based on the discovery of bones and tools, but can often be difficult to interpret. Human footprints provide unequivocal evidence of presence as well as behavior. White Sands provides the first unequivocal evidence of human habitation in the Americas during the Last Glacial Maximum said study co-author Dan Odess of the National Park Service. Not all archaeological sites contain such unequivocal evidence. One reason this discovery is important is that it makes the idea that other supposedly ancient sites really are evidence of human habitation much more plausible, even if the evidence they contain is less unequivocal. This does not mean that all these deposits are legitimate, but it does mean that they cannot be dismissed out of hand .