

Imagine an ostrich that tipped the scales at 1400 kilograms, standing twice as tall as a human, with a solid tail and massive body, plus long, feathered arms with sharp claws, and a turtle-like beak. That鈥檚 how a newly discovered dinosaur called Gigantoraptor looked as it roamed what is now China about 70 million years ago.
The huge size of Gigantoraptor is a surprise because it is a member of the oviraptorids, a group of flightless feathered dinosaurs closely related to birds, which mostly weighed less than 40 kilograms. Known since the 1920s, oviraptorids were toothless and probably omnivorous. 鈥淕igantoraptor would be a strange animal in any environment,鈥 says Tom Holtz of the University of Maryland in College Park.
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The partial fossil skeleton was found in Inner Mongolia and is from a young adult about 8 metres long. Many of Gigantoraptor鈥檚 features are unique, suggesting dinosaurs were more diverse than has been recognised, says lead author Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology in Bejing (Nature, vol 447, p 844). Its combination of slender limbs and long lower legs may have made it the fastest runner among large two-legged dinosaurs, he says.