Despite being underwater only 12,000 years ago, White Sands National Park, now an arid desert landscape, is replete with remnants of ancient human history.
The White Sands Missile Range, owned by the Department of Defense and surrounding the park, is home to the world's largest collection of Ice Age footprints. These footprints were left by people who depended on a vanishing lake in the region.
Among these finds, researchers have uncovered new evidence of ancient activity left in the sand, and it has changed their view of early human technology. Footprints, but not the kind left by feet, they were left by travois.
Travois (travois)-the earliest form of land transportation known today, made of long sticks and a basket or net, these primitive vehicles are a bit like a wheelbarrow without a wheel.
If pulled by a raised handle or handles, the basket attached to the sticks moved, allowing a person to slide a heavy load across the sand. "Every human has things to carry, but we have no mention of it until written histories," geoscientist Matthew Bennett and hominin paleoecologist Sally Reynolds wrote in an essay for Conversation magazine.
These histories usually point to 4,000 B.C. as the earliest human use of transportation technology, but Bennett, Reynolds and their colleagues at the U.K.'s Bournemouth University attribute the grass traces at White Sands to 20,000 B.C., which shifts the story back 16,000 years.
Study of ancient land transportation
Bennett and Reynolds, along with researchers from Cornell University, the National Park Service, the U.S. Geological Survey, the University of Alaska Museum of the North, and the University of Arizona, studied the grass tracks discovered in 2023 along with the famous Ice Age footprints on White Sands.
Photo: sfgate.com
At the time, researchers believed that the presence of humans in North America began 15,000 years ago, when the ice sheet began to retreat from the continent. But it turned out that the seeds, quartz grains and pollen embedded in the preserved footprints were 23,000 years old.
Researchers now have an even better idea of what life looked like in the Lake Otero area, which stretched for more than 2.5 kilometers in what is now New Mexico. In a paper published in the peer-reviewed scientific journal Quaternary Science Advances, the team from Bournemouth notes that the traces of grass indicate a much earlier adoption of land transportation than previously thought.
Before assuming that the tracks belonged to grass, the team divided them into three classes: types I, II and III. Type I tracks consisted of deep, single grooves, while Type II tracks consisted of shallow, wide single grooves. Type III tracks included double grooves with fixed spacing between them; they were often accompanied by human footprints. The researchers then set about determining what could not have produced the tracks.
Humans couldn't drag animal bones across the sand - no animal that lived in the area had bones of the right length and width, except mammoths, whose
bibs were "
incredibly heavy and bulky," as the researchers write. Even the mammoths' habit of dragging wood on the ground couldn't be to blame, since no mammoth prints have been found nearby, and the tracks would likely have been more disorderly if they had been made by
mammoths.
The tails of
lion cubs could not have left tracks, as their prints were also not found nearby. The footprints were not the result of a fleet entering Lake Otero, as they were inside, not filled with lake sediment. And the kayaks that might have been used to cross the lake were not quite right: many of the footprints were located far from the shoreline.
Photo: sfgate.com
However, the footprints could have come from another activity: collecting firewood. It's unlikely that the firewood collected at the lake would have been long and thin enough to match the footprints, but just in case, the researchers conducted an experiment by dragging weighty pieces of wood across the sand. The footprints they created matched some of the tracks they found, but not all of them.
By this point, the team already suspected it was dealing with grass tracks, according to Museum of the North archaeologist and former National Park Service chief scientist Daniel Odess.
"It seemed like such an obvious thing for humans to use," Odess says. "They're anatomically modern humans with big brains like you and me, and they were probably even more inventive than we are."
Vehicle experiments
Odess and Bennett decided to build their own grass-type vehicles to see if they were on the right track. They used these makeshift vehicles to tow "cargo" - in one case, Bennett's young daughter - across beaches in Maine and British Poole Harbor. The new tracks matched ancient ones found on White Sands.
Photo: sfgate.com
"If you're hunting and butchering a very large animal in a muddy area like this, you need a way to keep the meat clean," Odess says. "You don't want to drag your food through the mud. Grass is the perfect way to elevate your meat to keep it clean, plus you can easily move a lot of weight with it."
Ancient grasses were likely used to transport small children, as evidenced by footprints found near the rails: sometimes two pairs of footprints would run parallel across the grass, and then the smaller pair would disappear.
It turns out that Bennett's experiment with his daughter didn't get too far fetched either. "Sometimes we'd be working and then we'd pause and look at the whole thing and we'd get real chills," Odess says. - "Because it's so relational and yet so removed in time."
To preserve the integrity of such a culturally significant site, Odess and his colleagues worked with more than 20 indigenous groups to ensure proper treatment and reasonable research, he said. This allowed the team to excavate a minimal amount of trace evidence to support the theory of a grass managed by people whose history goes back far into the region's past.
When the team asked the indigenous consultants if they thought grasses may have been part of life at Lake Otero, many of them said their oral traditions reflected such use. Some tribes even gave names to these vehicles in their languages.
Photo: sfgate.com
"Most of the indigenous people I've talked to are not at all surprised at how ancient these footprints are. The archaeologists are surprised, but the Native people say, 'Congratulations, you just proved what we already know,'" Odesse said. "And that means that the ancestors of these people were the ones who saw mammoths and giant sloths roaming the landscape, and that's really cool."