Sinosaurus from southwestern China.

摘要

Early Jurassic Sinosaurus triassicus (=“ Dilophosaurus sinensis”) is the earliest large dinosaur predator from China; however, all the specimens of this species have remained poorly know. The Hewanzi specimen described in this thesis is the only well prepared one. Morphology of the crest and braincase of the Hewanzi specimen indicates that it possesses advanced characteristics that are more developed than in Dilophosaurus. A phylogenetic analysis shows Sinosaurus and Cryolophosaurus emerge as more derived theropods; they were recovered as more closely related to Averostra than to Coelophysis and Dilophosaurus. These results may suggest the Hewanzi specimen represents another species of Sinosaurus. A finite element analysis (FEA) suggests the structural features of the crest in Dilophosaurus and Sinosaurus cannot play a mechanical role during combat. In addition, a remodeled alveolus in the maxilla of Sinosaurus is the first confirmed example of dental pathology in a dinosaur.