High Quality Content by WIKIPEDIA articles! Yuanmousaurus was a sauropod dinosaur from the Middle Jurassic period of China. It is known from incomplete remains, but probably reached about 17 meters (56 ft) in length. The type species was Yuanmousaurus jiangyiensis, described by Lu Junchang et al. It is possibly closely related to Patagosaurus; and placed in a more basal position than Euhelopus but a more derived position than Omeisaurus.