New species of megaraptorid dinosaur found

Scientists have identified a new species of megaraptorid dinosaur in Argentina, whose carnivorous diet gave rise to their name meaning 'giant thieves'.
The new species with unique skull features, named Murusraptor barrosaensis, may help unveil the evolutionary origins of the megaraptorid clade.
The Patagonian region of Argentina has previously proven to be rich in fossils from the Late Cretaceous epoch, including a number of megaraptorids.
These medium-sized theropod dinosaurs, including South American genera Megaraptor, Orkoraptor and Aerosteon as well as genera from Australia and Japan, have characteristically large claws and air-filled, birdlike bones.
The fossils analysed in this study by Rodolfo Coria from the National Scientific and Technical Research Council (CONICET) in Argentina, and Phillip Currie from the University of Alberta in Canada was discovered in Sierra Barrosa, in northwest Patagonia.

It represents one of the most complete megaraptorids found, with an unusually intact braincase.

This specimen appears to be immature, but researchers suggest that the species is larger and slenderer than Megaraptor and comparable in size with Aerosteon and Orkoraptor.
While sharing many features with the other species, Musuraptor has distinctive facial features not previously seen among megaraptorids, as well as unusually shaped hip bones, researchers said.
Although phylogenetic analysis could not clearly determine evolutionary relationships, researchers 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.

"A new meat-eating dinosaur, Murusraptor barrosaensis, has been discovered from 80 million years old rocks from Patagonia, Argentina," said Coria.
"Although incomplete, the beautifully preserved bones of Murusraptor unveil unknown information about the skeletal anatomy of megaraptors, a highly specialised group of Mesozoic predators," he said.
The study was published in the journal PLOS ONE.