The surprising discovery of mammoth fossils in a paleontologist’s backyard led to an even more unexpected find.
The remains of a female mammoth and her calf, around 37,000 years old, show clear signs of carnage, providing new evidence that humans may have arrived in North America much earlier than previously thought.
Paleontologist Timothy Rowe learned of the fossils in 2013 when a neighbor saw something sticking out of a hillside on a New Mexico property Rowe owned.
Upon closer inspection, Rowe found tusk, a sunken mammoth skull, and other bones that appeared to be deliberately broken. I thought it was the place where two mammoths had been butchered.
“What we have is incredible,” Rowe said in a statement. “It’s not a charismatic place with a beautiful skeleton lying on its side. It’s all destroyed. But that’s the story.”
Rowe, a professor at the Jackson School of Geosciences at the University of Texas at Austin, specializes in vertebrate paleontology and does not generally study mammoths or early humans. But he couldn’t stop working on the investigation because of the location of the find.
Two six-week excavations were carried out at the site in 2015 and 2016, but analysis in the lab took much longer and is ongoing, Rowe said. Rowe is lead author of a new study offering an analysis of the site and its implications, published in the academic journal Frontiers in Ecology and Evolution in July.
“I have yet to fully process the cosmic coincidence of this showing up in my backyard,” Rowe wrote in an email.
Analysis of fossils
The many finds at the site depict what happened thousands of years ago, including bone tools, evidence of a fire, broken bones and other signs of human carnage from animals.
Long mammoth bones shaped like disposable knives were used to break up animal carcasses before fire helped to melt their fat.
According to the study, fractures created by brute force are observed in the bones. There were no stone tools at the site, but the researchers found scale knives made of bone with frayed edges.
A chemical analysis of the sediment around the mammoth bones showed that the fire was sustained and controlled and not caused by wildfires or lightning.
There was also evidence of pulverized bones and burned remains of small animals, including birds, fish, rodents and lizards.
The research team used CT scans to analyze the bones at the site, finding perforations that would have served to drain fat from the ribs and vertebrae. The humans who butchered the mammoths were meticulous, Rowe said.
“I excavated dinosaurs that were eaten by scavengers, but the pattern of disarticulation and bone breakage produced by human carnage was unlike anything I had ever seen,” Rowe said.
The most surprising detail about the site is that it is located in New Mexico, and previous tests have suggested that humans weren’t there until tens of thousands of years later.
Tracing the first human steps
Collagen extracted from mammoth bones helped researchers determine that the animals were slaughtered at the site between 36,250 and 38,900 years ago. This age range makes the New Mexico site one of the oldest ancient humans created in North America, the researchers said.
Scientists have debated for years when the first humans arrived in North America.
The 16,000-year-old Clovis culture is known for the stone tools it left behind. But a growing body of evidence suggests that the oldest sites in North America harbored a pre-Clovis population that had a different genetic lineage.
Older sites have a different kind of evidence, such as preserved footprints, bone tools, or animal bones marked by cuts from over 16 millennia ago.
“Humans have been in the Americas for more than twice as long as archaeologists have believed for many years,” Rowe said. “This finding indicates that humans achieved a global distribution much earlier than previously believed.”
The location of the site, which is in the western interior of North America, suggests that the first humans arrived well before 37,000 years ago, according to the study. These early humans likely traveled by land or along coastal routes.
Rowe said he wants to investigate the site for signs of ancient DNA.
“Tim has done excellent and thorough work that represents cutting-edge research,” retired Texas State University professor Mike Collins said in a statement. “He is charting a path that others can learn and follow.”
Collins was not involved in the study. He led research at the Gault Archaeological Site, which contains Clovis and pre-Clovis artifacts, near Austin, Texas.
“I think the deeper meaning of early human achievements of global distribution is an important new question to explore,” said Rowe.
“Our new techniques have provided subtle evidence of a human presence in the archaeological record, and I suspect there are other sites of comparable or even older age that have not been recognized.”
Source: CNN Brasil