Xing Lida1,*, Ariana Paulina-Carabajal2, Philip J. Currie3, Xu Xing4, Zhang Jianping1, Wang Tao5, Michael E. Burns3 and Dong Zhiming4
1 School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China;2 Museo Carmen Funes, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Av. Córdoba 55 (8318), Plaza Huincul, Neuquén, Argentina;3 University of Alberta, CW405 Biological Sciences Building, Edmonton, Alberta T6G 2E9, Canada；4 Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China;5 Lufeng Land and Resources Bureau, Lufeng 651200, ChinaThe authors thank Chairman Laigen Wang (World Dinosaur Valley Park, Yunnan Province, China) for providing the specimen for study. Eva Koppelhus (University of Alberta, Canada) also provided advice and support during the course of this project. CT scanning carried out at the Chaozhou Central Hospital was made possible by Songduan Li.
Abstract: The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is characterized by a large supraoccipital knob that is capped by a posterior projection of the parietal and two external foramina for the caudal middle cerebral vein, which is completely enclosed by the supraoccipital. The basicranium has well defined, short basipterygoid processes that project ventral to the basal tubera. The basisphenoid is expanded, projects posteroventrally, and is pierced by four pneumatic recesses. The endocranial morphology resembles that observed in other basal theropods—in particular some allosauroids—and has a strongly marked pontine flexure and a large dorsal expansion. The inner ear morphology is also similar to that observed in other basal theropods, with slender semicircular canals. The anterior semicircular canal is 20% larger than the posterior semicircular canal, and the angle formed between them is less than 90° when seen in dorsal view.
Abstract: The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is characterized by a large supraoccipital knob that is capped by a posterior projection of the parietal and two external foramina for the caudal middle cerebral vein, which is completely enclosed by the supraoccipital. The basicranium has well defined, short basipterygoid processes that project ventral to the basal tubera. The basisphenoid is expanded, projects posteroventrally, and is pierced by four pneumatic recesses. The endocranial morphology resembles that observed in other basal theropods—in particular some allosauroids—and has a strongly marked pontine flexure and a large dorsal expansion. The inner ear morphology is also similar to that observed in other basal theropods, with slender semicircular canals. The anterior semicircular canal is 20% larger than the posterior semicircular canal, and the angle formed between them is less than 90° when seen in dorsal view.
Xing Lida,*, Ariana Paulina-Carabajal, Philip J. Currie, Xu Xing, Zhang Jianping, Wang Tao, Michael E. Burns and Dong Zhiming.2014. Braincase Anatomy of the Basal Theropod Sinosaurus from the Early Jurassic of China[J]. ACTA GEOLOGICA SINICA(English edition),88(6):1653~1664
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