Bones from a mammoth butchery site show how humans shaped pieces of their long bones into disposable blades to break down their carcasses and melted their fat over a fire.
But, one key detail sets this site apart from others from that era. It’s in New Mexico – a place where most archaeological evidence places the first human activity tens of thousands of years later.
A recent study by scientists at the University of Texas at Austin suggests that the site offers some of the most conclusive evidence that humans settled in North America much earlier than previously thought.
Researchers have revealed a wealth of rarely found evidence in one place. It includes fossils with blunt fractures, bone splinter knives with worn edges, and signs of controlled fire. And thanks to carbon dating analysis on collagen extracted from mammoth bones, the site also has a sedentary age of 36,250 to 38,900 years ago, making it one of the oldest known sites left by the ancients. humans in North America.
“What we have is amazing,” said lead author Timothy Rowe, a paleontologist and professor at UT Jackson School of Geosciences. “It’s not a charismatic site with a beautiful frame arranged on the side. Everything is screwed up. But that’s the story. »
Rowe does not generally research mammoths or humans. He got involved because the bones appeared in his garden, literally. A neighbor spotted a weathered defense of a slope on Rowe’s property in New Mexico in 2013. When Rowe went to investigate, he found a sunken mammoth skull and other bones that appeared to be deliberately broken. It was apparently a butcher shop. But the earliest presumed human sites are shrouded in uncertainty. It can be notoriously difficult to determine what has been shaped by nature versus human hands.
This uncertainty has led to debate in the anthropological community about when humans first arrived in North America.
Although the mammoth site lacks any clearly associated stone tools, Rowe and his co-authors uncovered an array of supporting evidence by subjecting samples from the site to scientific laboratory analysis.
Among other findings, CT scans performed by the University of Texas High-Resolution X-Ray Computed Tomography Facility revealed bone flakes with microscopic fracture networks similar to those of freshly trimmed cow bones and wounds well-placed perforators that would have helped drain fat from ribs and vertebral bones.
“There are really only a few effective ways to skin a cat, so to speak,” Rowe said. “The butchery bosses are quite characteristic.”
Additionally, chemical analysis of the sediments surrounding the bones showed that the fire particles came from a sustained and controlled burn, not from a lightning strike or wildfire. The material also contained pulverized bones and the burnt remains of small animals – mostly fish (even though the site is over 200ft above the nearest river), but also birds, rodents and lizards. .
Based on genetic evidence from indigenous populations in South and Central America and artifacts from other archaeological sites, some scientists have proposed that North America had at least two founding populations: the Clovis and a pre-Clovis society with a different genetic lineage.
The researchers suggest that the New Mexico site, with its age and bone tools instead of elaborate stone technology, may lend support to this theory. Collins said the study adds to a growing body of evidence for pre-Clovis societies in North America while providing a toolkit that can help others find evidence that might have otherwise been overlooked.
“Tim has done excellent and thorough work that represents cutting edge research,” Collins said. “It’s about forging a path that others can learn from and follow.”
Co-authors include Jackson School professor Richard Ketcham and researchers Romy Hanna and Matthew Colbert, as well as scientists from the Gault School of Archaeological Research, University of Michigan, Aarhus University, and StaffordResearch.
Header image credit: Timothy Rowe / University of Texas at Austin