Dinosaur species may shed new light on megaraptorids

New York: A new megaraptorid dinosaur species discovered in Argentina's Patagonia Desert may help scientists find out the evolutionary origins of the megaraptorids represented by Megaraptor, Orkoraptor and Aerosteon.

The Patagonian region of Argentina has previously proven to be rich in fossils from the late Cretaceous epoch, including a number of megaraptorids whose carnivorous diet gave rise to their name meaning 'giant thieves'.

The new species discovered in Sierra Barrosa of Patagonia represents one of the most complete megaraptorids found, with an unusually intact braincase.

With unique skull features, the dinosaur was named Murusraptor barrosaensis. This specimen appears to be immature, but the researchers suggest that the species is larger and slenderer than Megaraptor and comparable in size with Aerosteon and Orkoraptor, according to the study published recently in the journal PLOS ONE.

The researchers, led by Argentine paleontologist Rodolfo Coria, found that the new species shared many features with the other species, it had distinctive facial features not previously seen amongst megaraptorids, as well as unusually shaped hip bones.

While phylogenetic analysis could not clearly determine evolutionary relationships, the authors note that these fossils provide new anatomical information which might help to resolve current debates as to whether the megaraptorids are a clade of the allosauroid or the coelurosaurid theropods.