Fossil bones discovered in Argentina, displaying cut marks indicative of butchering, suggest that humans were in southern South America approximately 21,000 years ago, much earlier than previously thought. These fossils belong to Neosclerocalyptus, a member of the glyptodont family, which inhabited the Americas for over 30 million years before becoming extinct around 10,000 years ago at the end of the Ice Age.
The researchers identified these cut marks on the bones as likely being made by stone tools, providing substantial evidence of Homo sapiens' presence in the area, even though no human remains were found at the site. Glyptodonts, although related to modern armadillos, were much larger—some species reaching the size of a small car. They featured a large, bony shell similar to that of a turtle, armored heads, robust tails, and short limbs.
Neosclerocalyptus was one of the smaller glyptodont species, with the individual in this study measuring around 6 feet (180 cm) in length and weighing approximately 660 pounds (300 kilograms). The cut marks were observed on the pelvis, tail, and body armor.
Mariano del Papa, an anthropologist from the National University of La Plata and the lead author of the study, stated that "the only ones capable of making them (these marks) were humans." This finding supports the hypothesis that humans arrived in the Americas earlier than previously believed. The role of humans in the extinction of many large mammals in the Americas remains a subject of debate, and the Neosclerocalyptus fossils provide some of the earliest evidence of human interaction with these large Ice Age animals.
These discoveries represent the oldest evidence of both Homo sapiens' presence and their interaction with large animals in southern South America during the Last Glacial Maximum, the peak of the last Ice Age. This significant discovery adds to our understanding of early human history in South America, highlighting the early and complex interactions between humans and their environment.