Was This Giant, Armadillo-Like Animal Butchered by Humans in Argentina 21,000 Years Ago?

For more than 30 million years, giant relatives of the modern armadillo, known as glyptodonts, roamed the Americas, before going extinct at the end of the last ice age. Now, new evidence suggests that humans in modern-day Argentina butchered one of these armored behemoths 21,000 years ago—long before our species was even thought to have arrived in the region.

A new study published Wednesday in PLOS ONE describes the remains of the massive creature, known as Neosclerocalyptus, which showed evidence of people using stone tools to access its meat. The finding adds to a recent string of discoveries that could upend the traditional view of when and how humans first settled the Americas. Estimates for humans’ arrival range from 13,000 to 20,000 years ago, and people weren’t thought to have reached the southern end of South America until about 16,000 years ago.

“Humans could have been present in South America much earlier than we thought and even earlier than what is assumed of the entry of people in North America,” study co-author Nicolás Rascovan, a biologist at the Pasteur Institute in France, tells New Scientist’s Christa Lesté-Lasserre.

Researchers uncovered the giant, armadillo-like specimen after a bulldozer exposed its vertebrae and pelvis on the banks of the Reconquista River in the Buenos Aires metropolitan area of Argentina. Weighing in at about 660 pounds, measuring almost six feet long and covered in armored scales, the animal would have been one of the smallest Neosclerocalyptus roaming the area in its day.

The scientists used radiocarbon dating to determine the animal died between 20,811 and 21,090 years ago. Initially, they didn’t see clear evidence that humans had butchered the creature. But during careful cleaning of the bones, they found 32 straight cuts. After ruling out that the marks were made by rodents, carnivorous predators or other factors like trampling, the team matched their shape to incisions likely to be made by stone tools.

Additionally, the cuts seemed to be focused on areas of the animal that would have had the highest concentrations of meat. Miguel Delgado, an archaeologist at the National University of La Plata in Argentina, tells CNN’s Katie Hunt that “the cut marks were not randomly distributed but focused on those skeletal elements that harbored large muscle packs like the pelvis and the tail.”

If further evidence emerges to confirm these conclusions, it would be an “extraordinary” finding in the contentious debate of when humans arrived in the Americas, Ben Potter, an archaeologist at the University of Alaska Fairbanks who was not involved with the study, tells New Scientist. But right now, it leaves several questions open.

“A red flag is the total absence of any associated human-made artifacts with these [bones],” Potter tells the publication. “Stone tools and debris are ubiquitous in actual human processing sites.”

The research team plans to continue excavating the site where they found the bones, which could reveal firm evidence of human presence. In the meantime, they say their findings fit the pattern of recent discoveries reshaping the timeline of humans in the Americas.

“Our results in conjunction with other evidence that has been found in eastern South America (Brazil), but also in North America (Canada and USA) and Central America (Mexico) proposes a distinct scenario for the first human peopling of the American continent,” Delgado tells Popular Science’s Laura Baisas. “The most likely date for the first human entry occurred between 21,000 and 25,000 years ago or even before. The interaction between humans and megafauna in southern South America occurred long before we thought.”

Rudy Molinek | READ MORE

Rudy Molinek is Smithsonian magazine's 2024 AAAS Mass Media Fellow.