Scientists have made the "unique" discovery of a fossil belonging to a previously unknown meat-eating dinosaur that had little arms and had a powerful head to ram its prey.
The skull of the Cretaceous Period dinosaur, named Guemesia ochoai, that lived about 70 million years ago was discovered in Argentina's northwestern Salta province.
It is an exciting find that has led scientists to consider whether it is part of a whole new species as it is so different.
The researchers said it likely belongs to a carnivorous group of dinosaurs called abelisaurs, which walked on two legs and possessed only stub-like arms, even shorter than those of North America's Tyrannosaurus rex.
The short arms may have forced Guemesia to rely on its powerful skull and jaws, the researchers said.
"It's so unique and so different from other carnivorous dinosaurs, which allows us to understand that we're dealing with a totally new species," said Federico Agnolin, lead author of a study on the dinosaur published in the Journal of Vertebrate Paleontology and a researcher with Argentine national science council CONICET.
The animal, that could have been young when it died, lived just a few million years before an asteroid impact at what is now Mexico's Yucatan peninsula that wiped out about three-quarters of Earth's species including the dinosaurs about 66 millions years ago.
Scientists believe abelisaurs roamed what is now Africa, South America and India, and several dozen specimens have
previously been dug up in Argentina - nearly all of them in southern Patagonia, far from the site of Guemesia's discovery.
"We know it had a very sharp sense of smell and was short-sighted," said Agnolin, noting that it would have walked
upright on its large feet, with its solid cranium leading the way.
"Some scientists think that could mean the animal hunted its prey by charging them with its head," Agnolin added.
The discovery adds to Argentina's reputation as a treasure trove of fossils of dinosaurs and other prehistoric creatures.
Guemesia takes its name from Argentine independence hero Martin Miguel de Guemes and Javier Ochoa, a museum worker who
made the discovery.
