Paleobiologists from the University of Zurich, along with colleagues from Venezuela and Colombia, have discovered the remains of an extinct giant freshwater turtle of the genus Stupendemys. The researchers reported the discovery in an article published in the journal Science Advances.
The fauna of the tropical belt of South America is one of the most diverse on the planet. The region's extinct animals are unique, as evidenced by the fossils of giant rodents and crocodiles, including crocodiles, alligators, caimans and gharials, that inhabited the now desert area of Venezuela. Five to ten million years ago, it was a humid swampy area teeming with life. One of its inhabitants was Stupendemys geographicus, a turtle species first described in the mid-1970s.
Now researchers have discovered new remains of this amazing species. The authors described the horned shell of a turtle of this species, the length of which was equal to 286 centimeters. Judging by the size of the individual's body, its mass was about 1145 kilograms - almost a hundred times more than that of its closest living relative, the large-headed Amazonian river turtle.
This new carapace has horns, unlike previously found flat specimens. This indicates that the appearance of the representatives of this species was different depending on the gender. It is assumed that males had horns on their shells, while females did not.
Despite its enormous size, Stupendemys geographicus had natural enemies. In many areas, the appearance of representatives of this genus coincides with the Purussaurus - the largest caimans. Most likely, the latter ate individuals of this giant tortoise, which follows not only from its size and dietary preferences, but also from marks on the shell, similar to those of the caiman teeth.
Researchers have also traced the evolutionary history of the giant tortoise and found that several species in the Amazon are direct relatives. In addition, new discoveries and studies of existing fossils from Brazil, Colombia and Venezuela indicate a much wider geographical distribution of Stupendemys than previously thought. The animal lived throughout the northern part of South America.