Open Paleo

Gigantoraptor

Xu et al., 2007 ji-GAN-to-rap-tor

From Greek gigas/gigantos, 'giant', + Latin raptor, 'thief/seizer'; means 'giant thief', referring to its status as the largest known oviraptorosaur

89.8–66.0 million years ago Coniacian–Maastrichtian, Late Cretaceous
Late Cretaceous stages

Gigantoraptor is a genus of large oviraptorosaurian dinosaur that lived in Asia during the Late Cretaceous period. It is known from the Iren Dabasu Formation of Inner Mongolia, where the first remains were found in 2005.

Under dispute

Gigantoraptor is now generally recovered as a basal caenagnathid (Longrich and colleagues, 2013; Lamanna and colleagues, 2014; Funston, 2020), a marked departure from its original description as a basal oviraptorid (Xu and colleagues, 2007). A minority result (Hartman and colleagues, 2019) still recovers it, with Microvenator, within Oviraptoridae. It is placed at Caenagnathidae following the prevailing view.

Diagnosis

  1. Short mandible less than 45% of femoral length, with a fossa on the lateral surface of the dentary close to the anterior end and a second fossa bounded dorsally by a lateral flange anterodorsal to the external mandibular fenestra.
  2. Tail composed of opisthocoelous anterior caudal vertebrae, amphicoelous middle ones, and procoelous posterior ones, with pleurocoels on most caudal vertebrae and a pair of vertically arranged pneumatic openings on the lateral surface of anterior caudal centra.
  3. Laterally bowed humerus with a prominent spherical humeral head, strongly medially curved deltopectoral crest, and a centrally constricted thick ridge along the posterior margin of the proximal half.
  4. Metacarpal I with a medial condyle three times as high as and extending much more distally than the lateral one; metacarpal II with a prominent dorsolateral process on the proximal end and a longitudinal groove on the ventral margin of the proximal third of the shaft.
  5. Femur with a constricted neck between the posteromedially oriented spherical femoral head and the anteroposteriorly wide trochanteric crest, and a patellar groove on the anterior surface of the distal end.
  6. Small calcaneum obscured from anterior view by the wide astragalar main body; proximal projection on the lateral margin of distal tarsal IV; metatarsal III with ginglymoid distal end.

Species

Gigantoraptor erlianensis Xu et al., 2007

Type species

Named for the Erlian basin in Inner Mongolia, China, where the holotype was discovered.

Holotype
LH V0011 , Long Hao Institute of Geology and Palaeontology
Material
Incomplete skeleton: nearly complete mandible, partial presacral vertebrae, most caudal vertebrae, nearly complete right scapula, much of the forelimbs, partial ilium, nearly complete pubes and hind limbs.
Horizon
Iren Dabasu Formation, Coniacian–Maastrichtian, Late Cretaceous , 89.8–66.0 million years ago
Locality
Saihangaobi, Inner Mongolia, China

References

  1. Xu, X.; Tan, Q.; Wang, J.; Zhao, X.; Tan, L. (2007). A gigantic bird-like dinosaur from the Late Cretaceous of China. Nature 447(7146): 844-847. Springer Science and Business Media LLC. doi:10.1038/nature05849 xu2007b
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the appearance features.

    jones2026c
  3. Lamanna, M. C.; Sues, H. D.; Schachner, E. R.; Lyson, T. R. (2014). A new large-bodied oviraptorosaurian theropod dinosaur from the latest Cretaceous of western North America. PLoS ONE 9(3): e92022. Public Library of Science (PLoS). doi:10.1371/journal.pone.0092022

    Described new oviraptorosaur, part of analyses departing from Gigantoraptor as basal oviraptorid.

    lamanna2014a
  4. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247

    Recovered Gigantoraptor within Oviraptoridae with Microvenator, a minority result.

    hartman2019a
  5. Longrich, N. R.; Barnes, K.; Clark, S.; Millar, L. (2013). Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae. Bulletin of the Peabody Museum of Natural History 54(1): 23-49. Bulletin of the Peabody Museum of Natural History. doi:10.3374/014.054.0102

    Phylogenetic analysis recovered Caenagnathidae including Gigantoraptor as monophyletic sister to Oviraptoridae

    longrich2013a
  6. Funston, G. F.; Chinzorig, T.; Tsogtbaatar, K.; Kobayashi, Y.; Sullivan, C.; Currie, P. J. (2020). A new two-fingered dinosaur sheds light on the radiation of Oviraptorosauria. Royal Society Open Science 7(10): 201184. The Royal Society. doi:10.1098/rsos.201184

    Recovered Gigantoraptor as a basal caenagnathid, not an oviraptorid.

    funston2020a