Study on Different Megafauna Species Reveal They Coexisted With Humans and Were Here Much Before Than Thought
Experts have tried to understand for several decades how long multiple extinct species inhabited the Earth. This helps researchers understand how Earth has changed across several periods. Several assertions are in place, but new findings continue to challenge them. This is what happened when some fossils from Brazil went through examination, according to IFL Science. Findings regarding these fossils have been published in the Journal of South American Earth Sciences.
These fossils belonged to mammalian megafauna. These giant mammals comprise animals like sabertoothed tigers, giant sloths, and mammoths. Prior studies claimed that this group went extinct around the start of the Holocene. However, this assertion was challenged when several fossils indicated that mammalian megafauna were alive on Earth even some 4,000 years ago. Some of these contradicting specimens were garnered from Itapipoca and the Rio Miranda Valley.
These specimens were found to be of giant sloths and camel-like animals. Researchers conducted carbon dating on these fossils, and they came out to be around 3,500 years old. "With the dating, we wanted to better understand the distribution of ancient megafauna in South America. What we found — 3,500-year-old species — was totally unexpected," said Geologist, Fábio Faria, of the Universidade Federal do Rio de Janeiro, stated Science News. The remains were fragments of teeth from different megafauna species. There were eight specimens in total, of which one came from an extinct genus of American llama called Palaeolama major, while one was of Xenorhinotherium bahiense, a camel-like creature with the nose of a tapir.
Examinations revealed that the creatures were quite young. "The ages obtained demonstrate that the latest ages of megafauna appearance in Brazil are associated with the middle and late Holocene," the authors added. This implies that these creatures coexisted with humans who arrived in South America somewhere between 20,000 and 17,000 years ago, stated IFL Science. This challenges certain theories cited as reasons for mammalian megafauna extinction. "The ages obtained in this analysis, together with archaeological evidence, demonstrate that the Overkill and Blitzkrieg theories are not plausible explanations for the extinction of South American megafauna," the authors added.
Overkill and Blitzkrieg theories argued that mammalian megafauna species went extinct because of human hunting and landscape modification. The new evidence, though, suggests that these mammals survived human coexistence, and therefore, some other reason was in play for their extinction.
Researchers believe that contrary to past beliefs, the extinction was not a homogeneous event and instead took place over a long time. "The study clearly shows that the famous Pleistocene-Holocene extinction was a long-term process of diversity loss of the Pleistocene mammals," said Ismar de Souza Carvalho, one of the researchers who worked on this study. Other experts believe that a group of these mammals possibly came to the site for refuge from life-threatening phenomena taking place elsewhere. "The environment in the Brazilian Intertropical Region was undergoing changes by that time," said Dimila Mothé, a paleoecologist at the Universidade Federal do Estado do Rio de Janeiro who did not participate in the study. "Open fields were turning into forests, and these animals might have had less area to graze and looked for refuge in the remaining savannah."