The partial skull of a 12-foot-tall ground sloth that lived about 3.58 million years ago was unearthed in Argentina and paleontologists have described it as being one of the oldest ever fossils of the animal that’s ever been found.
The extinct genus of ground sloths, known as Megatherium, existed from the Early Pliocene Epoch (around 5 million years ago) until the end of the Pleistocene Epoch (about 11,700 years ago) and lived in South America. The gigantic Megatherium americanum species, that was about the size of an elephant and weighed as much as 4 tons, lived in Argentina, Bolivia, and Uruguay during the Pleistocene Epoch.
Since it could stand up and walk on its hind legs, it was the biggest ever bipedal mammal. In fact, when it stood up, it reached a height of between 12 and 13 feet. Footprints belonging to the Megatherium americanum were discovered in Argentina that date back approximately 14,000 years.
While they lived in groups with other members of its species, they could have also lived alone in caves. It is believed that they more than likely ate food that was moderately soft but they could have hunted other types of prey as they had strong forelimbs and long claws.
The mammal lived alongside humans for some time as cut marks were discovered on their bones which suggested that ancient humans would feast on them.
As for the partial skull that was found, it belonged to a large juvenile and was unearthed near San Eduardo del Mar in Argentina’s Buenos Aires province.
Dr. Nicolás Chimento, who is from the Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ – CONICET, as well as his colleagues from the Museo Municipal Punta Hermengo, Miramar, the Universidad Maimónides, CICYTTP-CONICET, and CIC PBA-UNMDP, stated, “Megatherium remains are very common in almost the entire Argentine territory, however, it is the first time that the remains of such high antiquity have been found, which is only comparable to a find made a few years ago in Bolivia.”
They went on to say, “This constitutes the first undoubted record of Megatherium from the Pliocene of Argentina, and one of the oldest records for the genus,” adding, “This finding blurs previous biogeographical proposals sustaining that the genus originated in the High Andes and later dispersed to the lowlands.” (Pictures of the skull can be seen here.)
Their research was published in the Journal of South American Earth Sciences where it can be read in full.