The recent discovery of the leg bone of a giant sloth more than 13 million years old – reported today by the magazine Biology Letters, de la Royal Society, in a study signed by François Pujos and the Peruvian Rodolfo Salas-Gismondi, who received funding from the Concytec- echa light on the behavior of the large reptiles and mammals that inhabited and ruled the Amazonia in the Miocene.
In the South America back then, a mega-wetland system extended over what is now known as the western part of the Amazon (current territories of Bolivia, Brazil, Colombia, Peru and Venezuela). The Pebas Formation was home to assemblages of multi-taxa crocodiles, with the giant caiman Purussaurus as the main predator.
In these swamps, not many confrontations between this species and the mylodontid Pseudoprepotherium had been reported, but the finding of a tibia of this one, with 46 predatory teeth marks, allows us to glimpse a somewhat more agitated coexistence.
“The combination of shallow, round and bisected holes and large perforations that collapsed extensive portions of cortical bone points to a young or sub-adult Purussaurus (approximately 4 m in total length) as the perpetrator. Other known crocodilians of the Pebas system were too small in adulthood or had discordant feeding anatomy to be considered.”Says the paper.
Speaking to the Andean Agency, Salas-Gismondi, researcher and professor at the Universidad Peruana Cayetano Heredia, indicated that the Purussaurus was at the time the largest non-marine predator since the extinction of non-avian dinosaurs. Hence, this discovery in the Peruvian Amazone – which the pair of researchers have been addressing since 2004 – constitutes an unusual snapshot of the reptile’s dietary preferences. It also reveals that before reaching their giant size, up to 10 meters, the young individuals could have fed on terrestrial mammals approximately the size of a capybara, even lurking from the water towards the shore, as seems to have been the case with this victim. , to which the fossil corresponds.
Salas-Gismondi also highlighted that the research and the finding of the sloth fossil have even more value as it is a discovery in the Amazon, “A place of extreme difficulty to find evidence of this nature.”
In light of its extensive biodiversity, the area, the researcher explained, still hides important treasures that interest the scientific world to understand how the complex ecological dynamics was built and the incredible species that inhabited it millions of years ago.