Human footprints found in New Mexico may be even older than scientists originally thought, dating back to more than 20,000 years ago.
In 2021, American and British archaeologists estimated prints found at White Sands National Park in southern New Mexico were about 21,000 to 23,000 years old. This suggests some of the earliest evidence of human activity in the Americas, about 10,000 years earlier than previously believed.
However, many scientists were skeptical. But a follow-up study published Thursday in the journal Science has confirmed those findings based on radiocarbon dating, which examines decay that’s up to 60,000 years old.
Footprints found in White Sands National Park in New Mexico date to 23,000 years ago, making them the first ‘unequivocal evidence’ of homo sapiens in the New World thousands of years before most estimates
Dr Jeff Pigati, lead researcher of the 2021 study and geologist at the US Geological Survey (USGS) in Denver, said: ‘Every dating technique has strengths and weaknesses, but when three different techniques all converge on the same age range, then the resulting ages are exceptionally robust.’
Study co-author Dr Kathleen Springer of the USGS added: ‘Our original results were controversial, and we knew all along that we needed to independently evaluate the seed ages to develop community confidence in them. This paper is that corroborative exercise.’
Homo sapiens arose in Africa more than 300,000 years ago and later migrated across the globe. Scientists believe our species entered North America from Asia by trekking across a land bridge that once connected Siberia to Alaska.
The prints – which are flat, a possible sign the people were barefoot – reveal more than just a date, the researchers said. They offer a glimpse into what life was like during the Upper Paleolithic Era, which started about 40,000 years ago.
Previous archaeological evidence had suggested human occupation of North America started roughly 16,000 years ago, according to study co-author Dr Matthew Bennett, a professor of environmental and geographical sciences at Bournemouth University in England.
‘Indigenous peoples were there earlier than thought, before the great ice barrier at the height of the last glacial maximum closed the way south from Alaska. By what route and how they got there is yet to be determined. White Sands is just one point on the map for now,’ he said.
‘The work confirms the chronology we set out in 2021 for the site using independent methods, labs and approaches.’
Most of the prints were left by teens and younger children, with occasional tracks from adults, as well as some from mammoths, giant ground sloths, and dire wolves, researchers said.
‘The footprints left at White Sands give a picture of what was taking place — teenagers interacting with younger children and adults,’ Dr Bennett said in 2021.
Earlier prints found on the White Sands trackway indicate young humans were hunting giant ground sloths in the area by purposely stepping in the animal’s tracks.
Other studies have found evidence of people living on the North American continent thousands of years earlier than previously believed.
In July 2020, stone tools were discovered in a cave in Mexico known as Chiquihuite that revealed archaeological evidence of human occupation dating back to 27,000 years ago.
In 2018, 150,000 ‘unique’ stone tools were found northwest of Austin, Texas that suggested people lived on the continent as far back as 20,000 years ago.
Human footprints dating back 15,600 years were found in Chile in 2019, which at the time, were believed to be the oldest known human footprint tracks in the Americas.
Designated a megatrack site in 2014, White Sands contains the world’s largest collection of fossilized footprints from the Pleistocene era, which is dated from 2.58 million to 11,700 years ago.