New Fossil Discoveries in South America Challenge Traditional Megafauna Extinction Timelines

Traditional views have long held that ancient megafauna—such as ground sloths—vanished by approximately 11,000 years ago, marking the early Holocene. However, recent fossil discoveries are challenging this narrative. For example, last year a woolly mammoth was reported to date back as recently as 4,000 years, and now additional megafauna remains from South America appear even younger. Researchers have published findings in the Journal of South American Earth Sciences that suggest these fossils can be dated to around 3,500 years ago.

A team of geologists from the Federal University of Rio de Janeiro conducted carbon dating on fragments of giant animal teeth excavated from two paleontological sites in Brazil. The results were unexpected: tooth fossils attributed to the camelid Palaeolama major and the camel-like Xenorhinotherium bahiense both yielded dates of approximately 3,500 years. Given that humans are believed to have arrived in South America between 20,000 and 17,000 years ago, these findings imply that interactions between humans and these megafauna persisted for several thousand years longer than previously assumed.

While earlier studies had noted the presence of megafauna remains across the Americas—and even in other regions—dating from about 6,000 to 5,000 years ago, the new discoveries have sent shockwaves through the academic community. Experts suggest that these findings may lead to a significant reassessment of South American natural history, highlighting that species extinctions often occur in a non-uniform manner. Notably, northeastern Brazil might have served as a refuge for the last survivors of these giant animals.

Overall, these revelations not only challenge long-standing perceptions of the extinction timeline of ancient megafauna but also offer valuable new insights into the factors influencing their distribution and eventual demise.