Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-30T19:16:36.290Z Has data issue: false hasContentIssue false

The anatomy and systematic position of the theropod dinosaur Chilantaisaurus tashuikouensis Hu, 1964 from the Early Cretaceous of Alanshan, People's Republic of China

Published online by Cambridge University Press:  29 August 2008

ROGER B. J. BENSON*
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK Natural History Museum, Cromwell Road, London SW7 5BD, UK
XU XING
Affiliation:
Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O. Box 643, Beijing 100044, People's Republic of China
*
*Author for correspondence: [email protected]

Abstract

There is little consensus on the systematic position of the colossal theropod dinosaur Chilantaisaurus tashuikouensis from the Cretaceous (Aptian–?Albian or Upper Cretaceous) Ulansuhai Formation of Inner Mongolia, which has been recovered as a derived member of both Allosauroidea and Spinosauroidea by numerical phylogenetic analyses. Redescription of the type material of C. tashuikouensis reveals an unusual combination of morphological features that render determination of its systematic position problematic. It possesses anatomical features that have been proposed as synapomorphies of Neotetanurae: a preacetabular fossa on the ilium, and a wedge-shaped cross-section of the shaft of the third metatarsal. It also shares some features with specific allosauroid taxa: a pronounced ulnar epicondyle on the humerus, and a prominent medial shelf bounding the preacetabular fossa on the ilium (also present in tyrannosauroids). However, it lacks some features that are present in all other allosauroids: a marked depression on the anterior surface of the distal humerus adjacent to the ulnar condyle, and a humerus that is less than 0.4 times the length of the femur; it furthermore possesses a tibial astragalar facet that is approximately 10% of the tibial length, which suggests a more basal position within Tetanurae. Chilantaisaurus shares certain features with some spinosauroids: an enlarged and elongated first manual ungual, and a suprastragalar buttress that has been modified to a vertical ridge, but these characters are not unique to spinosauroids. A highly reduced fourth trochanter may be an autapomorphy of Chilantaisaurus, as has previously been suggested, or unite the taxon with Coelurosauria in an entirely novel grouping. On the basis of these observations it is likely that Chilantaisaurus is a neotetanuran, but unlikely that it is an allosauroid. Chilantaisaurus may belong to an alternative lineage of very large theropods that continued into the Cretaceous from the diversification of basal neotetanurans during the Middle Jurassic.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barsbold, R. & Maryanska, T. 1990. Segnosauria. In The Dinosauria, 2nd edition (eds Weishampel, D. B., Dodson, P. & Osmólska, H.), pp. 408–15. Berkeley: University of California Press.Google Scholar
Britt, B. B. 1991. Theropods of Dry Mesa Quarry (Morrison Formation, Late Jurassic), Colorado, with emphasis on the osteology of Torvosaurus tanneri. Brigham Young University Geology Studies 37, 172.Google Scholar
Brochu, C. R. 2003. Osteology of Tyrannosaurus rex: insights from a nearly complete skeleton and high-resolution computed tomographic analysis of the skull. Memoirs of the Society of Vertebrate Paleontology 7, 1138.CrossRefGoogle Scholar
Carpenter, K., Miles, C. & Cloward, K. 2005. New small theropod dinosaur from the Upper Jurassic Morrison Formation of Wyoming. In The Carnivorous Dinosaurs (ed. Carpenter, K.), pp. 2348. Bloomington: Indiana University Press.Google Scholar
Charig, A. J. & Milner, A. C. 1986. Baryonyx, a remarkable new theropod dinosaur. Nature 324, 359–61.CrossRefGoogle ScholarPubMed
Charig, A. J. & Milner, A. C. 1997. Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Bulletin of the Natural History Museum, Geology Series 53, 1170.Google Scholar
Chure, D. J. 1998. Chilantaisaurusmaortuensis, a large maniraptoran theropod from the Early Cretaceous (Albian) of Nei Mongol, PRC. Journal of Vertebrate Paleontology 18, 33A34A.Google Scholar
Clark, J. M., Maryanska, T. & Barsbold, R. 2004. Therizinosauroidea. In The Dinosauria, 2nd edition (eds Weishampel, D. B., Dodson, P. & Osmólska, H.), pp. 151–64. Berkeley: University of California Press.CrossRefGoogle Scholar
Coria, R. A. & Currie, P. J. 2006. A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina. Geodiversitas 28 (1), 71118.Google Scholar
Coria, R. A. & Salgado, L. 1995. A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature 377, 224–6.CrossRefGoogle Scholar
Currie, P. J. & Carpenter, K. 2000. A new specimen of Acrocanthosaurus atokensis (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA. Geodiversitas 22, 207–46.Google Scholar
Currie, P. J. & Chen, P.-J. 2001. Anatomy of Sinosauropteryx prima from Liaoning, northeastern China. Canadian Journal of Earth Sciences 38, 1705–27.CrossRefGoogle Scholar
Dong, Z. 1979. [Cretaceous dinosaurs of Hunan, China]. In [Mesozoic and Cenozoic Red Beds of South China: Selected Papers from the “Cretaceous-Tertiary Workshop”] (eds Institute of Vertebrate Paleontology and Paleonanthropology & Nanjing Institute of Paleontology), pp. 342–50. Nanxiong: Science Press (in Chinese).Google Scholar
Galton, P. M. & Molnar, R. E. 2005. Tibiae of small theropod dinosaurs from Southern England. In The Carnivorous Dinosaurs (ed. Carpenter, K.), pp. 322. Bloomington: Indiana University Press.Google Scholar
Gauthier, J. A. 1986. Saurischian monophyly and the origin of birds. In The Origin of Birds and the Evolution of Flight (ed. Padian, K.), pp. 155. Memoirs of the California Academy of Science no. 8.Google Scholar
Harris, J. D. 1998. Reanalysis of Acrocanthosaurus atokensis, its phylogenetic status, and implications, based on a new specimen. New Mexico Museum of Natural History and Science Bulletin 13, 175.Google Scholar
Holtz, T. R. Jr. 1994. The phylogenetic position of the Tyrannosauridae: implications for theropod systematics. Journal of Paleontology 68, 1100–17.CrossRefGoogle Scholar
Holtz, T. R. Jr. 2001. The phylogeny and taxonomy of the Tyrannosauridae. In Mesozoic Vertebrate Life (eds Tanke, D. H. & Carpenter, K.), pp. 6483. Bloomington: Indiana University Press.Google Scholar
Holtz, T. R. Jr, Molnar, R. E. & Currie, P. J. 2004. Basal Tetanurae. In The Dinosauria, 2nd edition (eds Weishampel, D. B., Dodson, P. & Osmólska, H.), pp. 71110. Berkeley: University of California Press.CrossRefGoogle Scholar
Hu, S.-Y. 1964. [Carnosaurian remains from Alashan, Inner Mongolia.] Vertebrata PalAsiatica 8, 4263 (in Chinese, with English summary).Google Scholar
Hutchinson, J. R. 2001. The evolution of femoral osteology and soft tissues on the line to extant birds (Neornithes). Zoological Journal of the Linnean Society 131, 169–95.CrossRefGoogle Scholar
Hutt, S., Martill, D. M. & Barker, M. J. 1996. The first European allosaurid dinosaur (Lower Cretaceous, Wealden Group, England). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1996, 635–44.CrossRefGoogle Scholar
Kellner, A. W. A. & Campos, D. de A. 1996. First Early Cretaceous theropod dinosaur from Brazil with comments on Spinosauridae. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1996, 151–66.CrossRefGoogle Scholar
Kobayashi, y. 2001. Bonebed of a new gastrolith-bearing ornithomimid dinosaur from the Upper Cretaceous Ulansuhai Formation of Nei Mongol Autonomous Region of China. Journal of Vertebrate Paleontology 21 (3), 68A69A.Google Scholar
Kobayashi, Y. & , J.-C. 2003. A new ornithomimid dinosaur with gregarious habits from the Late Cretaceous of China. Acta Palaeontologica Polonica 48 (2), 235–59.Google Scholar
Madsen, J. H. 1976. Allosaurus fragilis: a revised osteology.Utah Geological and Mineralogical Survey, Bulletin 109, 3163.Google Scholar
Madsen, J. H. Jr & Welles, S. P. 2000. Ceratosaurus (Dinosauria, Theropoda) a revised osteology. Miscellaneous Publications of the Utah Geological Survey 2, 180.Google Scholar
Marsh, O. C. 1881. Principal characters of the American Jurassic Dinosaurs. Part V. American Journal of Science, series 3 21, 417–23.CrossRefGoogle Scholar
Martill, D. M., Cruikshank, A. R. I., Frey, E., Small, P. G. & Clarke, M. 1996. A new crested maniraptoran dinosaur from the Santana Formation (Lower Cretaceous) of Brazil. Journal of the Geological Society, London 153, 58.CrossRefGoogle Scholar
Novas, F. E., De Valais, S., Vickers-Rich, P. & Rich, T. 2005. A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids. Naturwissenschaften 92 (5), 226–30.CrossRefGoogle ScholarPubMed
Osmólska, H. & Roniewicz, E. 1970. Deinocheiridae, a new family of theropod dinosaurs. Palaeontologica Polonica 21, 519.Google Scholar
Ostrom, J. H. 1978. The osteology of Compsognathus longipes Wagner. Zitteliana 4, 73118.Google Scholar
Owen, R. 1842. A report on British fossil reptiles. Part II. Reports of the British Association for the Advancement of Science 1841, 60204.Google Scholar
Rauhut, O. W. M. 2003. The interrelationships and evolution of basal theropod dinosaurs. Special Papers in Palaeontology 69, 1213.Google Scholar
Riabinin, A. N. 1914. [Report on a dinosaur from Transbaikalia]. Trudy Muzeia Petra Velikogo 8, 113–40 (in Russian).Google Scholar
Sadleir, R., Barrett, P. M. & Powell, H. P. 2008. The anatomy and systematics of Eustreptospondylus oxoniensis, a theropod dinosaur from the Middle Jurassic of Oxfordshire, England. Palaeontographical Society Monographs 160 (627), 182.CrossRefGoogle Scholar
Sereno, P. C., Beck, A. I., Dutheil, D. B., Gado, B., Larsson, H. C. E., Lyon, G. H., Marcot, J. D., Rauhut, O. W. M., Saleir, R. W., Sidor, C. A., Varicchio, D. D., Wilson, G. P. & Wilson, J. A. 1998. A long-snouted predatory dinosaur from Africa and the evolution of spinosauroids. Science 282, 12981302.CrossRefGoogle Scholar
Sereno, P. C., Dutheil, D. B., Iarochene, M., Larsson, H. C. E., Lyon, G. H., Magwene, P. M., Sidor, C. A., Varricchio, D. J. & Wilson, J. A. 1996. Predatory dinosaurs from the Sahara and Late Cretaceous faunal differentiation. Science 272, 986–91.CrossRefGoogle ScholarPubMed
Sereno, P. C., Wilson, J. A., Larsson, H. C. E., Dutheil, D. E. & Sues, H.-D. 1994. Early Cretaceous dinosaurs from the Sahara. Science 266, 451–76.CrossRefGoogle ScholarPubMed
Sun, A.-L., Li, J.-L., Ye, X.-K., Dong, Z.-M. & Hou, L.-H. 1992. The Chinese Fossil Reptiles and Their Kins. Beijing: China Ocean Press, 260 pp.Google Scholar
Vickaryous, M. K., Russell, A. P., Currie, P. J. & Zhao, X.-J. 2001. A new ankylosaurid (Dinosauria: Ankylosauria) from the Lower Cretaceous of China, with comments on ankylosaurian relationships. Canadian Journal of Earth Sciences 38, 1767–80.CrossRefGoogle Scholar
Weishampel, D. B., Barrett, P. M., Coria, R. A., Le Loeuff, J., Xu, X., Zhao, X., Sahni, A., Gomani, E. M. P. & Noto, C. R. 2004. Dinosaur Distribution. In The Dinosauria, 2nd edition (eds Weishampel, D. B., Dodson, P. & Osmólska, H.), pp. 517606. Berkeley: University of California Press.CrossRefGoogle Scholar
Xu, X., Tan, Q., Wang, J., Zhao, X. & Tan, L. 2007. A gigantic bird-like dinosaur from the Late Cretaceous of China. Nature 447, 844–7.CrossRefGoogle ScholarPubMed