Scientists uncover ancient footprint that suggests humans came to North America 23,000 years ago

Picture a time when prehistoric humans roamed the wetlands of what is now New Mexico, unaware that their everyday activities would leave a mark for us to study thousands of years later. The fossilized footprints discovered at White Sands National Park offer a rare glimpse into the lives of these ancient people, revealing stories that static bones and stone tools cannot tell.

Footprints alone cannot tell us who these prehistoric humans were, but a recent study has unveiled a surprising revelation about this group, per Science.org. Contrary to the commonly held belief that the ancestors of modern Native Americans arrived on the continent around 13,000 to 16,000 years ago, this study suggests that these footprints date back to a staggering 20,000 to 23,000 years ago, placing these humans in North America during the Ice Age, much earlier than previously thought.

This groundbreaking research, initially published in 2021 and further supported by a recent study, challenges our understanding of North American history. The initial study used radiocarbon ancient seeds that had been found alongside the footprints of the same early time frame, but some experts questioned the reliability of this dating method due to the potential for old carbon reservoir effects.

To corroborate these controversial dates, the researchers turned to additional dating methods, pollen dating and optically stimulated luminescence dating of sediments. Astonishingly, both methods independently confirmed the earlier date range, reinforcing the notion that ancient humans were living in New Mexico during a period when it was dramatically different from what we see today.

The footprints themselves offer a poignant connection between those who view them today and the people who made them millennia ago. They tell stories that can never be fully revealed through artifacts or fossilized bones alone. For instance, one set of prints appears to belong to a woman and a toddler. These footprints capture the toddler intermittently walking on its own and being carried by the woman, a vivid testament to the daily life of these ancient people.

Other footprints paint a picture of ancient hunters tracking a giant sloth. Their footprints follow the sloth's tracks, occasionally overlapping them, suggesting a pursuit that may have ended in success or failure. Unfortunately, there is no evidence to reveal the outcome of this ancient hunt. The footprints were preserved in the Tularosa Basin, a region that once teemed with life during the last Ice Age. What is now a desert landscape covered in gypsum dunes was once home to prairie-like grasslands, conifer forests and a vast body of water known as Lake Otero. This lush environment attracted not only humans but also a variety of now-extinct species, including ancient camels, mammoths, and ground sloths, as well as predators like American lions and dire wolves.

The initial dating of the footprints relied on the radiocarbon dating of ancient ditch grass seeds found near the prints. This method led to the groundbreaking conclusion that humans had walked these shores approximately 21,130 to 22,860 years ago, thousands of years earlier than previously thought. To address the dating concerns, the researchers turned to different methods.

They analyzed terrestrial pollen collected from the same layers as the seeds, using a meticulous process that involved isolating and identifying pollen grains. Additionally, they dated quartz needles found in the gypsum dunes using optically stimulated luminescence dating. Remarkably, all three dating methods produced consistent results, supporting the notion that humans were present in North America during the Last Glacial Maximum.

Traditionally, researchers thought that the first Americans arrived around 13,000 to 16,000 years ago, crossing over a land bridge from Siberia to Alaska as the last ice age waned. However, evidence has been mounting for an earlier arrival, possibly around 20,000 years ago, mainly along coastal routes. Genetic studies have also suggested that the ancestral lineage of Native Americans diverged from other populations around 20,000 years ago, with migrations into the Americas occurring as the ice age waned.

While some genetic modeling studies propose an even earlier entry, perhaps as long as 30,000 years ago, archaeological evidence has been limited, with most findings relating to migration after the Last Glacial Maximum. Whether these ancient humans were part of a small, isolated group or a broader population remains a subject of debate. Nevertheless, these footprints in the gypsum sands of White Sands National Park offer a remarkable glimpse into a far more ancient history of human presence in North America.

Editor's note: This article was originally published on October 11, 2023. It has since been updated.