Monday, July 24, 2017

Murusraptor barrosaensis. Image credit: Jan Sovak.

With hollow hips, big body and a pair of savage claws, this newly discovered species refuses to fit neatly in the dinosaur family tree.

A new species of dinosaur – Murusraptor barrosaensis – was named in 2016 in the journal PLOS One, thanks to the discovery of one of the most complete fossils of a Megaraptorid on record.

Megaraptorid dinosaurs are medium-sized and walk on two legs. They’re characterised by large claws and bird-like features. The name “Megaraptor” translates to “giant thief” – a reference to their carnivorous ways.

The clad includes Megaraptor from modern-day South America, as well as Australian dinosaurs Rapator and Australovenator, among others.

The family’s newest addition, Murusraptor, was discovered in Sierra Barrosa, in the fossil-rich Patagonian region of Argentina. Murus is Latin for “wall” and refers to the location of the fossil, in the side of a sandy canyon in 80-million-year-old rocks.

“Although incomplete, the beautifully preserved bones of Murusraptor unveil unknown information about the skeletal anatomy of megaraptors, a highly specialised group of Mesozoic predators,” says Rodolfo Coria from Argentina’s National Scientific and Technical Research Council and co-author of the paper.

Skull and body reconstructions of Murusraptor barrosaensis. Discovered bones are in white. CREDIT: CORIA ET AL, 2016, PLOS ONE

The fossil, which included a significant portion of skull, 31 teeth, pelvis and tibia, belonged to an immature dinosaur, but the new species appears to be bigger than its cousin Megaraptor.

Murusraptor bears unique facial features in the details of its bone structure as compared to other Megaraptorid dinosaurs, as well as differently-shaped hip bones.

The researchers say the discovery could contribute to questions that still surround the Megaraptorid clan, including its positioning among the wider theropod group.