likely members of the same genus, with O. junghsiensis as the most basal species. The cladogram from Tan et al., 2020 below shows a possible phylogenetic position: Paleoecology Omeisaurus lived in dense forests. Different species of Omeisaurus sometimes shared habitats with each other (O. junghsiensis and O. tianfuensis, for example). In addition to other species of Omeisaurus, Shunosaurus and Datousaurus are also known from the Xiashaximiao Formation, while Mamenchisaurus is present in the Shangshaximiao Formation. Yangchuanosaurus is a large theropod from the Shangshaximiao, and it probably preyed on sauropods. The smaller Xuanhanosaurus was also present. In the Xiashaximiao, another theropod, Gasosaurus, was also present, as was the herbivorous stegosaur Huayangosaurus''. The latter probably did not compete with sauropods for food. References Britt, Carpenter et al. (2002). Encyclopedia of Dinosaurs.. Publications international, Ltd., Lincolnwood Illinois.. The Middle Jurassic dinosaur fauna from Dashanpu, Zigong, Sichuan. Volume 4. Sauropod dinosaurs (2). Omeisaurus tianfuensis. He, X., Li, K. and Cai, Sichuan Publishing House of Science and Technology, Chengdu ; 1-143 (1988). The dinosaurian remains from Sichuan Basin, China. Dong, Z., Zhou, S. and Zhang, Y. PALAEONTOLOGIA SINICA SERIES C (No. 23) i-iii; 1-145 (1983). Middle Jurassic dinosaurs of Asia Mamenchisaurids Taxa named by Yang Zhongjian Fossil taxa described in 1939 Paleontology in Sichuan