Science Magazine has a story about the discovery of some giant turtle fossils in Columbia and Venezuela.  The turtles, called Stupendemys geographicus, lived about 12 million years ago.  Males weighed about 1100 kilograms.  These new fossils show they bore unusual large horns off the front of their shells, which they probably used to battle with each other.  All the details can be found in a paper which appeared in the Journal Science Advances.

This is the first time such horned remains have been found, even though the species was first described in 1976. At the time, scientists had uncovered only fragments of S. geographicus shells.

But over the past 6 years, paleontologist Edwin Cadena of Del Rosario University and his colleagues uncovered several complete S. geographicus fossils in northern Venezuela and in Colombia’s Tatacoa desert, which for the first time included fragments of a jaw. Those fragments closely matched jaw pieces from fossils in Brazil and Peru that had been assigned to other species.

The jaws are a close enough match that all the remains should be classified as S. geographicus, Cadena and his colleagues propose in a paper published today in Science Advances. That means this species, which weighed nearly as much as a hippopotomus, once ranged across a large swath of territory, from northwest Brazil, through Peru, Colombia, and all the way to the coast of Venezuela. At the time, the region was a vast series of rivers and wetlands called the Pebas system.