Mammoth bones and “ghost” ancient human footprints are the latest evidence in a scientific debate about when humans first reached America.
The fossilized bones, in particular, may indicate that humans lived tens of thousands of years before the generally accepted date for the arrival of the first Native Americans of around 10,000 B.C. lived in North America
Researchers say radiocarbon data from chemicals in the mammoth bones of a mother and her calf suggest the animals lived in what is now New Mexico about 37,000 years ago. Fracture patterns on the bones show they were slaughtered by people who therefore must have lived there at the same time, the researchers added. But the findings are disputed by some other scientists, who say the fractures could have been caused naturally.
The latest “ghost” footprints were now found a few weeks ago at an Air Force missile site in a Utah desert. Scientists believe they’re around 12,000 years old, but this is only the second time such footprints have been found, and they support last year’s discovery of ghost footprints in New Mexico, which are believed to be at least 21,000 years old – although this find, too, is controversial.
The mammoth bones at the so-called Hartley site in northern New Mexico, on rocks high above a tributary of the Rio Grande, are being hailed as the most conclusive evidence yet that humans arrived in the Americas by crossing a “land” up to 50,000 years ago. went bridge” between today’s Siberia and Alaska.
The researchers say they are confident in their dating and interpretation that the fractures on them were caused by repeated impacts with sharp objects during their deliberate slaughter. They also say there is evidence that fire was used selectively to cook many of the bones.
“I think it’s a rock-solid radiocarbon date,” said paleontologist Timothy Rowe, a professor in the Jackson School of Geosciences at the University of Texas at Austin. “Skeptics will scrutinize everything, but I think we ticked all the boxes.”
Rowe is the lead author of a study of the mammoth bones published last month in the journal Frontiers in Ecology and Evolution.
He said the fractures and tiny splinters of bone caused by the slaughtering process are also distinctive and seen at slaughter sites of similar ages in Europe and Asia: “If this site were in northern Siberia, nobody would blink.”
The idea that the mammoths were slaughtered by early humans is supported by other recent finds, including human footprints in New Mexico’s White Sands National Park and stone tools said to have been made in a cave in northern Mexico 33,000 years ago.
But the idea and the evidence are disputed by other scientists. The dating of the White Sands footprints has been questioned, and some scholars believe the objects from Mexico are not tools at all, but rather sharp rocks of course.
And they deny that the fractures in the mammoth bones could only have been caused by humans; Instead, they could have been caused by a landslide or some other natural event.
“The fracture patterns on these mammoth bones at this point can definitely be man-made,” said anthropologist Andre Costopoulos, a professor at the University of Alberta in Edmonton, who wrote a paper detailed online study the latest research. “But they are not necessarily diagnostic for a human presence.”
“We don’t have conclusive evidence yet because there are other possible explanations that need to be ruled out first, and they haven’t been,” he said.
The lack of distinctive stone tools at the Hartley site is also a problem. The researchers say the people who slaughtered the mammoths may not have used sophisticated stone tools, just primitive tools indistinguishable from natural bone or rock.
But other scientists say there is no evidence for this and that even primitive people could expect better tools at the time.
Archaeologist Ben Potter, formerly at the University of Alaska Fairbanks and now at Liaocheng University in China, said there was evidence from Africa, Europe and the Far East that around 47,000 years ago Homo sapiens used complex stone tools, and hence theirs Absence from the Hartley site is significant.
He said in an email that he’s not convinced by the latest research on the mammoth bones and the idea that they show humans arrived in America so long ago. “Anything is possible. However, we just need to have evidence to support the claim,” he said. “I don’t think they have enough evidence left, and certainly not at this point.”
However, some other scientists are more convinced and suggest that others may be reluctant to face the possibility that some humans arrived in the Americas as early as 50,000 years ago.
“The research looks very thorough,” said Spencer Lucas, curator of paleontology at the New Mexico Museum of Natural History and Science. “At what point will the archaeological community wake up and smell the coffee? There’s so much evidence,” he said.
“I’m not saying this is the ultimate evidence… but you have the White Sands footprints and the [Mexico] Website – all sorts of evidence is accumulating pointing to human occupation of the New World 20,000 years ago and I don’t see why this idea is still worth discussing.”
https://www.nbcnews.com/science/science-news/mammoth-bones-ghost-footprints-add-heated-debate-first-humans-north-am-rcna40238 Mammoth bones and “ghost” footprints add to heated debate about the first humans in North America