Washington, Dec 18 (ANI): Scientists have claimed to have discovered the fossils of a completely new giant dinosaur that lived 70 million years ago in Argentina.
According to a report in National Geographic News, the dinosaur's incomplete skeleton, including head, neck, back, and foot bones, was extracted from rocks in the far-southern Patagonia region in Argentina.
"At 16.5 to 21 feet long (5 to 6.5 meters) long, depending on its tail size, 'Austroraptor cabazai' is among the largest of the slender, carnivorous, two-legged dinosaurs called raptors," said Fernando Novas, the lead researcher behind the discovery.
Novas and colleagues were able to virtually reconstruct Austroraptor's complete skeleton, by using the dinosaur's closest relatives as references.
The new raptor, or dromaeosaur, belongs to a South American dromaeosaur group known as the unenlagiines, according to Novas.
In contrast to their relatives in the Northern Hemisphere, including the Velociraptors from Jurassic Park, unenlagiines had long, low heads and small conical teeth.
Northern dromaeosaurs had taller, shorter heads with fewer, but stronger, blade-like teeth.
The new raptor represents the "the largest dromaesaurid discovered in the Southern Hemisphere," according to a research paper by Novas and colleagues.
Seventy million years ago, Patagonia was a series of plains crossed by rivers filled with fish and turtles, whose fossils were found alongside Austroraptor.
Living in this fertile land alongside duck-billed herbivores such as titanosaurs and hadrosaurs, Austroraptor preyed on larger animals than its smaller relatives, thanks to its increased heft and girth, determined Novas.
Because paleontologists have found mostly smaller crow- and turkey-size raptors in South America, the new find turns the evolutionary history of raptors-northern and southern-upside-down, according to Novas.
"It's the first documentation of giant raptors in Patagonia measuring 5 meters (16.5 feet) or more," Novas said. "No one expected this, it's a new lineage," he added.
The researchers call Austroraptor "bizarre" because of its short arms, which, along with its large size, distinguishes the new raptor from its unenlagiine relatives.
Novas said that the new raptor is the first ever found with short arms.
Its shorter arms and more robust thigh bones, which supported the heavy animal, rule out any possibility of flying, he added.
The new find places raptors in the "big league" of dinosaurs, said Paul Sereno, a paleontologist at the University of Chicago.
"This was a monster raptor that makes the Velociraptor look like kid's play," said Sereno. "At five meters long with a sickle-shaped claw, it was an amazing predator," he added. (ANI)