Humans lived in South America many thousands of years earlier than previously believed, during the height of the Last Ice Age. A new archaeological study discovered this by analyzing a trio of necklaces made from ground sloth bones.
The project wades into an ongoing debate over when and how Homo sapiens, who evolved in Africa and first spread to Europe and Asia, made it to the relatively remote Americas.
In the conventional view of American settlement, human beings crossed over from Asia to modern-day Alaska and went on to explore the Americas around 15,000 years ago. Widespread settlement of North and South America took about a thousand more years, archaeologists say, and many years after the Last Ice Age.
In recent times, however, more unconventional finds have come to light that have attempted to revise the timeline, such as the new pendant study.
In 2021, a paper reported on fossilized human footprints found in New Mexico that the researchers dated to between 21,000 years and 23,000 years ago. And in 2020, scientists uncovered a cave in northern Mexico that contained stone tools dated to some 33,000 years ago.
In 2017, a famous paper claimed to have identified 24,000-year-old butchery marks on bones found in a cave in the Yukon area.
The Santa Elina site. (Credit: Águeda and Dennis Vialou)
The bone pendants from the new study originated in the Santa Elina rock shelter in Western Brazil, a well-studied site where scientists found the skeletons of two extinct giant ground sloths. The pendants came not from the 3,700-pound beast’s skeleton but from osteoderms embedded in its hide like armadillo armor.
Using stone tools, ancient people had bored holes into the bones to loop some kind of cord through, similar to how Ice Age cultures in Europe created bone jewelry.
With three different techniques, the researchers had dated the layer where they’d found the bone pendants to some 27,000 years ago, roughly the time of the Last Glacial Maximum. During that phase, Ice Age glaciers would have peaked and ocean levels would have dropped to 400 feet lower than today.
Painted art at the Santa Elina site. (Credit: Águeda and Dennis Vialou)
For whatever reasons, the people living in Santa Elina sought to express themselves through bone adornments. The crafts-people’s work was important to them, too, as evinced by how worn the pendants were from use, the researchers found.
So how did such treasures wind up in the dirt? Well, two of the pendants broke at some point and were probably discarded, while the other may have been lost.
But there’s no telling. The paper suggests that the people who produced the bones had lived in the shelter, but then again, they may have been traveling through. Either way, some ancient group discarded osteoderms in patterns under the shelter that resembled piles, according to the researchers.
The team also found stone tools near the ground sloth skeletons, but the bones had degraded too badly to look for any so-called butchery marks. A common strategy for detecting the presence of ancient humans – the same one used for this study – is to look for the marks left by their tools.