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New Findings Challenge Timeline of Megafauna Extinction in South America

Recent discoveries indicate that some species of megafauna may have persisted much longer than previously believed. Traditional paleontological consensus holds that large prehistoric animals, such as ground sloths, disappeared around 11,000 years ago, coinciding with the beginning of the Holocene epoch. However, a notable find of a 4,000-year-old woolly mammoth last year began to question this narrative. Now, additional fossil discoveries from South America are pushing back the extinction timeline even further, with evidence suggesting some species lived as recently as 3,500 years ago, as detailed in the February 15 edition of the Journal of South American Earth Sciences.

Geologist Fábio Faria and his team conducted carbon dating on eight teeth fragments from various megafauna species excavated from two paleontological sites in Brazil. The unexpected discovery of two teeth—one belonging to the camelid Palaeolama major and the other to the tapir-like Xenorhinotherium bahiense—upended their assumptions. “Our goal with the dating was to better comprehend the distribution of ancient megafauna in South America. Finding species that lived 3,500 years ago was entirely surprising,” commented Faria, affiliated with the Universidade Federal do Rio de Janeiro.

P. major, a distant relative of modern llamas, thrived in South America, while X. bahiense featured a llama-like body with a tapir’s nose. This revelation implies that these megafauna coexisted with humans for several millennia longer than previously understood, considering that humans were believed to have arrived on the continent between 20,000 and 17,000 years ago.

Previous studies have recorded other fossil findings dating back around 6,000 and 5,000 years across the Americas and beyond, as noted by Dimila Mothé, a paleoecologist from the Universidade Federal do Estado do Rio de Janeiro, who was not involved in this study. She remarked that the new findings were “astonishing” and could significantly alter our understanding of South America’s prehistoric narrative.

The research supports the notion that extinctions are rarely uniform, according to Mothé. Given that both fossils were sourced from the same site in northeastern Brazil, it is posited that this area may have functioned as a sanctuary for the surviving members of species such as P. major and X. bahiense.

“At that time, the Brazilian Intertropical Region was undergoing substantial ecological changes,” Mothé explained. “As open grasslands transitioned into forested areas, these animals may have faced shrinking habitats, prompting them to seek refuge in the remaining savanna-like regions.”

Furthermore, Mothé emphasized that the extinction of these animals may not be attributed solely to human intervention or climate shifts but could result from a complex interplay of both factors.

Faria expressed that this new evidence could redefine existing perspectives. “Historically, Brazilian researchers tended to adopt the prevailing North American narrative that megafauna were primarily eliminated through overhunting. We were so convinced that our megafauna were limited to the early Holocene that we didn’t even think to date our fossils,” he stated. “Now, there’s significant work ahead.”

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