by Some types of megafauna may have existed much longer than the paleontological canon suggests.
Current thinking says that old, large animals such as ground sloths were extinct about 11,000 years ago – at the start of the Holocene, the current geological era. The discovery of a 4,000 -year -old Wooly Mammoth, reported last year, helped to hit that story. Now other Megafauna fossil finds from South America seem to be even younger: they date from about 3,500 years ago, researchers report in the 15 February Journal of South American Earth Sciences.
Geologist Fábio Faria and colleagues carbon dated eight fragments of megafauna teeth of different types of two paleontological places in Brazil. The age of two of those teeth – one of the Camelid Paleolama major and the other of the Camelid-like Xenorhinotherium Bahiense – The team overwhelmed. “With the dating we wanted to better understand the distribution of the old Megafauna in South America. What we found-3,500 year old species-washes totally unexpected, “says Faria, from the Universidade Federal, Rio de Janeiro.
P. Major is an old family member of the contemporary Lamas from South America. X. BahienseIn the meantime, the body of a lama and the nose of a tapir had. The new finding suggests that these animals were in contact with people – who arrived in South – America between 20,000 and 17,000 years ago – for a few thousand years longer than once.
Earlier research has noticed other Megafauna fossils around 6,000 and 5,000 years old on the American continent and elsewhere, says Dimila Mothé, a paleoecologist at the Universidade Federal do Estado do Rio de Janeiro who did not participate in the study. But the new finding, she says, “is amazing and opens the door to rewrite South -American history.”
The study adds more evidence to the idea that extinction is rarely homogeneous, says Mothé. Since both fossils were found at the same location in northeast Brazil, Mothé believes that the region might be a refuge for remaining people of species such as such as such as such as such as P. Major And X. Bahiense.
“The environment in the Brazilian intertropical region underwent changes by that time,” she says. “Open fields turned into forests, and these animals might have had less area to graze and sought refuge in the remaining Savannah.”
The extinction of the animals may not only happen due to human activity or climate change, says Mothé. It was perhaps a confluence of both.
For Faria, the discovery is a change of thoughts. Brazilian researchers were able to take over the North -American view that Megafauna was being swept away by Vuurhaast. “After that dominant view, we were so sure that our Megafauna was from the start of the Holocene, we did not even go out with our fossils,” he says. Now, “There is a lot of work to do.”
