Chilantaisaurus

Chilantaisaurus Temporal range: Late Cretaceous, 92 Ma PreЄ Є O S D C P T J K Pg N ↓
Restoration of C. tashuikouensis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Infraorder:	Carnosauria
Superfamily:	Allosauroidea
Family:	Neovenatoridae
Genus:	Chilantaisaurus Hu, 1964
Species
C. tashuikouensis Hu, 1964 ?C. sibiricus (Riabinin, 1914) Molnar, Kurzanov & Dong, 1990

Chilantaisaurus ("Ch'i-lan-t'ai lizard") is a genus of neovenatorid theropod dinosaur from the late Cretaceous Ulansuhai Formation of China (Turonian stage, about 92 million years ago). The type species, C. tashuikouensis, was described by Hu in 1964. Chilantaisaurus was a large theropod, estimated as weighing between 2.5 metric tons (2.8 short tons)^[1] and 4 metric tons (4.4 short tons).^[2] Recently, Brusatte et al. (2010) estimated it to weight 6,000 kilograms (13,000 lb).^[3]

Classification

Hu considered Chilantaisaurus to be a carnosaur related to Allosaurus,^[4] though some subsequent studies suggested that it may be a spinosauroid, possibly a primitive member of the spinosaurid family (Sereno, 1998; Chure, 2002; Rauhut, 2001) because it had large claw on the forelimbs thought to be unique to that group. Other studies suggested that it could be a member of an alternate offshoot of neotetanuran theropods, with some similarities to allosauroids, spinosauroids, and coelurosaurians.^[5] A 2009 study noted that it was difficult to rule out the possibility that Chilantaisaurus was the same animal as the carnosaur Shaochilong, which is from the same geological formation. However, they did note an enormous size difference between the two.^[6] Further study by Benson, Carrano and Brusatte found that it was not as closely related to Shaochilong as first thought, but that it was a carnosaur (of the family Neovenatoridae), closely related to Allosaurus as Hu had initially thought.^[1]

Several species have been described based on very poor remains. Chilantaisaurus? sibiricus is based on a single distal metatarsal IV from the Turginskaya Svita of the Buryat Autonomous Soviet Socialist Republic, Russia, dating to the Early Cretaceous (Berriasian-Hauterivian).^[7][8] It is poorly described, so its relationships cannot be accurately determined (Chure, 2002). "Chilantaisaurus" maortuensis was reclassified as Shaochilong maortuensis in 2009.^[6] Bones attributed to "Chilantaisaurus" zheziangensis come from a therizinosaur, and may in fact come from the same individual as the type specimen of Nanshiungosaurus.

References

1. ^ ^{a b} Benson R.B.J., Carrano M.T, Brusatte S.L. (2010). "A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic". Naturwissenschaften 97 (1): 71–78. doi:10.1007/s00114-009-0614-x. PMID 19826771. 
2. ^ Paul, G.S. (1988). Predatory Dinosaurs of the World. New York: Simon and Schuster. p. 314. 
3. ^ Brusatte, S.L.; Chure, D.J.; Benson, R.B.J.; Xu, X. (2010). "The osteology of Shaochilong maortuensis, a carcharodontosaurid (Dinosauria: Theropoda) from the Late Cretaceous of Asia". Zootaxa 2334: 1–46. http://mapress.com/zootaxa/2010/f/z02334p046f.pdf. 
4. ^ Hu, S.-Y. (1964). "Carnosaurian remains from Alashan, Inner Mongolia." Vertebrata PalAsiatica, 8: 42–63. [In Chinese, with English summary]
5. ^ Benson, R.B.; and Xu, X. (2008). "The anatomy and systematic position of the theropod dinosaur Chilantaisaurus tashuikouensis Hu, 1964 from the Early Cretaceous of Alanshan, People's Republic of China". Geological Magazine published online (6). doi:10.1017/S0016756808005475. 
6. ^ ^{a b} Brusatte, S., Benson, R., Chure, D., Xu, X., Sullivan, C., and Hone, D. (2009). "The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids." Naturwissenschaften, DOI: 10.1007/s00114-009-0565-2
7. ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. ISBN 0-520-24209-2.
8. ^ http://home.comcast.net/~eoraptor/Carnosauria.htm#Chilantaisaurussibiricus

External links

• Chilantaisaurus in the Dinosaur Encyclopedia

Dinosaurs portal