Gigantoraptor
| Gigantoraptor Temporal range: Late Cretaceous
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| Genus: | Gigantoraptor Xu et al., 2007
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G. erlianensis Xu et al., 2007 (type) | |
Gigantoraptor is a genus of giant oviraptorosaurian dinosaur that lived 85 million years ago during the late Cretaceous Period.[1] It was discovered in 2005 in the Iren Dabasu Formation, Erlian basin, in Inner Mongolia. Xu et al. found that it shared a common ancestor with and belonged to the same family as Oviraptor, but in comparison, Gigantoraptor was much larger, approximately 35 times larger than its likely close relative, Caudipteryx.[2] At 8 metres (26 ft) long and weighing about 1.4 tonnes it is nearly 3 times as long and much heavier than the largest oviraptorosaur hitherto known, Citipati.
Its similarity to birds includes anatomical features such as a beak instead of toothed jaws. No direct evidence of feathers was preserved with the skeleton, but the authors inferred their presence based on the fact that Gigantoraptor was a member of the Oviraptorosauria, a group known to include many feathered species. Most unequivocal feathered dinosaurs found to date are small; however, evidence suggests that other large oviraptorids such as Citipati almost certainly had feathers as well.[3]
The diet of this animal is a mystery. Although some oviraptorosaurs such as Caudipteryx and Incisivosaurus are thought to have been primarily herbivorous, Gigantoraptor had hind legs with proportions that allowed for fast movement (it was probably more nimble than the ponderous Tyrannosaurus), and large claws, a combination that is not usually found in herbivores of this size.
The only known specimen is the incomplete and disassociated remains of a single individual that died at an estimated 11 years of age (determined from growth lines in one of the leg bones), and therefore possibly not full-grown.[1] Its discovery was documented on film: Xu Xing reenacted the discovery of a sauropod for a Japanese documentary. As he wiped the bone clean, he realized it was not from a sauropod, but from an unidentifiable theropod in the size class of Albertosaurus. He then stopped the filming to secure the serendipitous find.
References
- ^ a b Xu, X., Tan, Q., Wang, J., Zhao, X., and Tan, L. (2007). "A gigantic bird-like dinosaur from the Late Cretaceous of China." Nature, 447: 844-847.
- ^ Remains of giant bird-like dinosaur unveiled CBC
- ^ Paul, G.S. (2002). Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Baltimore: Johns Hopkins University Press.
External links
- news@nature.com: "Giant bird-like dinosaur found".
- Skeletal reconstruction of a Gigantoraptor raising itself up on one foot. Known bones are white. Human is 175cm tall. Credit: Li Rongshan/IVPP.
- Fleshed-out restoration of a Gigantoraptor. Credit: Julius T. Csotonyi
- Yahoo! News: China finds new species of big, bird-like dinosaur
- Description: Factsheet with picture english/german at Dinosaurier-Web
