Brief
University of Arizona team dates White Sands footprints to 23,500‑21,700 years ago
Researchers used pollen and radiocarbon data to pinpoint the age and environmental context of the footprints.
By Felo News Desk · Published
Researchers at the University of Arizona have confirmed that the human footprints discovered in White Sands National Park, New Mexico, date to the last Ice Age, roughly 23,500–21,700 years ago, according to a study published this week in Science Advances.
What happened
The footprints were first uncovered in 2006 in a dry lakebed that once held Lake Otero. By analysing hundreds of thousands of prehistoric pollen grains extracted from the sediment surrounding the prints, the team determined the age range and reconstructed the climate conditions experienced by the track‑makers.
What the reports add
Popsci reported that the USGS Radiocarbon Laboratory provided the radiocarbon dates, while the University of Arizona geoscientist Jessica Tierney explained that the unique sediment allowed reconstruction of plant distribution, precipitation, temperature and aridity at a high temporal resolution. The analysis showed that within a single generation the surrounding conifer forest shifted to oak‑ and sage‑dominated plains, and that Lake Otero fluctuated in size for about 1,500 years before disappearing.
What was said
"The White Sands sediments are unique in that they allow us to reconstruct environmental conditions during the last ice age at a very high temporal resolution," Tierney told Popsci. She added, "And throughout that whole sequence, people were walking there, leaving their tracks alongside those of mammoths, giant sloths and dire wolves."
How it came about
Earlier debates centered on whether the footprints pre‑dated the widely accepted 16,000–12,000‑year migration window. The new pollen‑based approach provides a direct environmental context that supports the older age estimate, reshaping understandings of early human presence in North America.
Key facts
- The White Sands footprints are dated to 23,500–21,700 years ago. (popsci.com)
- Researchers analysed hundreds of thousands of prehistoric pollen grains from the tracks. (popsci.com)
- The study was published in the journal Science Advances. (popsci.com)
- Environmental reconstructions show rapid shifts from conifer forest to oak‑sage plains within decades. (popsci.com)
- Lake Otero fluctuated for about 1,500 years before receding completely. (popsci.com)
Sources
- [1] popsci.com — originally reported as “North America’s oldest human footprints tell a tale of ice age chaos”
