The Denver-based U.S. Geological Survey scientists who this month confirmed the oldest known human footprints in the Americas at White Sands National Park say their findings open the door for fossil hunting at hundreds of ancient basins around the country, including the Great Salt Lake.
The findings based on repeated testing, using multiple dating methods, place humans in North America thousands of years earlier than previously thought, a scientific paradigm shift.
“This is going to open a whole new avenue in the field of archaeology,” said USGS research geologist Kathleen Springer, co-lead author of a paper published in the journal Science. “We were working in White Sands around one dried-up lake. Well, there’s hundreds of those around the United States.”
A colleague recently found a footprint in Utah near the Great Salt Lake, which has yet to be dated, Springer said. “Maybe more and more older sites will be found.”
The footprint confirmation is reverberating among archaeologists who study the timing of humans moving from Asia into North America. A dominant view has held that humans first arrived around 13,000 years ago, based on the dating of tools found in Clovis, N.M.
In September 2021, USGS and National Park Service researchers found the footprints at White Sands and announced, after initial radiocarbon testing of grass seeds, that they were 21,000 to 23,000 years old – implying humans lived in North America up to 10,000 years earlier than once thought and evolved for thousands of years alongside large Ice Age animals.
Their discovery was met with skepticism. Now they’ve buttressed their initial results through painstaking radiocarbon testing of fossilized pine pollen found in the footprints and through luminescence testing that measured the age of quartz crystals.
“Now we have evidence humans were here” between 21,000 and 23,000 years ago, well before the end of the Ice Age, Springer said. “This is a time stamp – footprints on the ground. The question is how they got here. People may have come down the West Coast.”
And how did they live? Ancient lakes that held water would have attracted humans and animals, said USGS research geologist Jeff Pigati, co-lead author of the study. At White Sands, thousands of footprints preserved in clay give a window into the lives of human ancestors and interactions with animals. Some prints came from adults walking with small children. Others came from humans surrounding a giant sloth before it fled.
Standard textbook science has held that glaciers receded and that “people came in and wiped out animals” by over-hunting, Pigati said. “But these results show that people and the mega-fauna co-existed for thousands of years before the Ice Age animals went extinct.”
