human footprint
(Photo : Pixabay / Falco )

In a new study, scientists made use of various techniques to show that the footprints of humans spotted in White Sands National Park are roughly 23,000 years old.

Oldest Known Human Footprints in North America

With their age of 23,000 to 21,000 years, the paleo-human footprints spotted in White Sands National Park serve as the oldest known human footprints in North America.

This new study serves as a response to an earlier 2021 study done by the same research team. In this earlier study, the researchers used unreliable material, an aquatic plant's seeds, for checking the footprints' age. Some archaeologists pointed this out in a 2022 rebuttal. These archaeologists also suggested the use of optically stimulated luminescence (OSL) dating, which involves the estimation of time passed since the exposure of feldspar or quartz grains to intense sunlight or heat.

For the new study, the researchers made use of two dating methods, including OSL dating, for checking the age of the trackway. They found that the footprints' layers were at least 21,500 years old.

Aside from this, the team also isolated and then performed radiocarbon dating on three earth samples with each on respectively containing 75,00 conifer pollen grains from the same layers of footprints of the aquatic plant. The 23,000-year age aligned with the quartz grains and seeds.

Now, with the three studies' results consolidated, findings suggest that the age of the tracks range from 23,000 to 21,000 years. This makes them date back to the Last Glacial Maximum period roughly 26,500 to 19,000 years ago. This period was the last ice age's coldest time.

Jefrey Pigati, co-leader of the study, explains that when the first study was released, several archaeologists reached out to the group and expressed that it was just a matter of time as they knew that humans arrived much earlier. Now, the study offers concrete evidence that humans were present during the Last Glacial Maximum.

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Criticisms Surface

However, anthropology professor Loren Davis from the Oregon State University, who is an author of the rebuttal, explains that based on the map that shows where the team took the samples for OSL dating, it is clear that the three OSL ages are from sediments that are stratigraphically situated between the horizons of the trackways. Hence, it is possible that the quartz grains could have been deposited first and then the footprints were later on deposited over them roughly 19,800 to 16,200 years ago.

Davis explains that this is why it is important that the authors get OSL ages from samples that kept the footprints buried, adding that pollen samples could have shifted through the layers of the site as time passed.

Nevertheless, other experts were impressed by the study findings.

Proof of Inhabitants Before the Arrival of the Clovis People

The age of the trackways are quite essential. In the past, archaeologists believed that Clovis people were the first settlers in the Americas roughly 13,00 years ago. These people were known to have lead-shape and sharp-edged stone points that were spotted at North American archaeological sites.

It was only in the last few decades that archaeologists were able to find solid proof that there were pre-Clovis inhabitants in the area. However, several of these areas harbored evidence that is shaky, while others were only found to be a couple of thousands of years before the Clovis settlement.

These trackways in the White Sands now serve as the oldest North American site that offers direct human evidence. It also remarkably pushes back the first Americans' arrival date.

RELATED ARTICLE: Fossilized Footprints From 21,000 Years Ago Fuels New Speculation When Humans Arrived in the Americas

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