Remains of a raptor found in Patagonia -- the very southern tip of South America -- are the first confirmed raptor dinosaur fossils to come from the Southern Hemisphere.
Neuquenraptor argentinus was six feet from head to tail and brandished a razor-sharp claw for slashing prey. It lived about 90 million years ago.
Researchers in 1996 found fragments of the dinosaur's vertebrae and ribs, as well as parts of its legs and a left rear foot, complete with the signature raptor claw. They have worked since then to analyze the fossils.
Neuquenraptor lived during the late Cretaceous period -- roughly the same time that the Velociraptor of "Jurassic Park" fame. At that time, Earth had two giant supercontinents -- one called Laurasia that eventually split into Europe, Asia, and North America, and another called Gondwana that became Australia, Africa, Antarctica, and South America.
Because Neuquenraptor was found in Patagonia, it must have lived on Gondwana, researchers conclude. All other verified species of raptor have been found on land that was once Laurasia.
"That's what was most striking," said Diego Pol, a postdoctoral researcher at Ohio State University. "Given the geographic location, you wouldn't expect to find a raptor there. So from the beginning we knew we had an interesting finding."
Since Gondwana and Laurasia were completely separated by ocean 90 million years ago, the find suggests that a common raptor ancestor probably roamed both supercontinents before they split apart from an even larger land mass, Pangea -- some 150 million years ago, during the late Jurassic period.
"Up to now, all known raptor species were exclusive to the Northern Hemisphere," Pol said. "And they all date to a time way after the splitting of the two land masses."
The discovery was made with the help of the Argentine Museum of Natural History and was reported last week in the journal Nature.
Pangaea began to break up about 225-200 million years ago. This animation shows how it unfolded.