On a semiarid Patagonian landscape 85 million years ago, a formidable meat-eater called Tratayenia rosalesi reigned as the apex predator, part of an enigmatic dinosaur group that menaced South America and Australia for tens of millions of years. It was a member of a group called megaraptorids that lived in the Southern Hemisphere from about 105 to 85 million years ago. The group was recognized by paleontologists only in the past few years, and all of its members -- including Tratayenia -- are known only from incomplete skeletons. "Using the remains of different species, including Tratayenia, we can make something like a 'police composite' of a megaraptorid skeleton," Lamanna added. The best known member of Tratayenia's group is Megaraptor, which lived slightly earlier in Patagonia and wielded 16-inch (40-cm) claws.

Source: dna March 29, 2018 10:07 UTC