分类: 生物学 >> 生物学其他学科 提交时间: 2018-12-04 合作期刊: 《古脊椎动物学报》
摘要: A cervical vertebra recovered from the Middle Jurassic Lower Member of the Shaximiao Formation in Town of Puan, Yunyang County, Chongqing is assigned to an species undeterminata of the sauropod dinosaur Omeisaurus based on morphological and comparative study. The centrum of this mid-cervical is much hollower than solider with extremely developed fossa/foramen complex and has a high ratio (5.05) of its anteroposterior length excluding the articular ball divided by the mean value of the posterior articular surface mediolateral width and dorsoventral height. Additional features of this cervical include central length about twice the total vertebral height, a prominent midline keel on the central ventral surface, deep and long cavities bounded by centroprezygapophyseal lamina/ intraprezygapophyseal lamina and centropostzygapophyseal lamina/intrapostzygapophyseal lamina, respectively, a coel on the dorsal half of the postzygapophyseal centrodiapophyseal fossa, long prone epipophysis extending beyond the postzygapophysis facet, anteroposteriorly length of the neural spine about half the length of the centrum, and concavities on the anterior one third lateral surface of the neural spine. Therefore, this discovery reveals new morphological information on Omeisaurus, and this Omeisaurus-bearing Puan dinosaur quarry represents the easternmost occurrence of this genus.
分类: 生物学 >> 动物学 提交时间: 2017-11-07 合作期刊: 《古脊椎动物学报》
摘要: A new crested theropod, Shuangbaisaurus anlongbaoensis gen. et sp. nov., is reported. The new taxon is recovered from the Lower Jurassic Fengjiahe Formation of Shuangbai County, Chuxiong Yi Autonomous Prefecture, Yunnan Province, and is represented by a partial cranium. Shuangbaisaurus is unique in possessing parasagittal crests along the orbital dorsal rims. It is also distinguishable from the other two lager-bodied parasagittal crested Early Jurassic theropods (Dilophosaurus and Sinosaurus) by a unique combination of features, such as higher than long premaxillary body, elevated ventral edge of the premaxilla, and small upper temporal fenestra. Comparative morphological study indicates that “Dilophosaurus” sinensis could potentially be assigned to Sinosaurus, but probably not to the type species. The discovery of Shuangbaisaurus will help elucidate the evolution of basal theropods, especially the role of various bony cranial ornamentations had played in the differentiation of early theropods.