• Yunnan, People's Republic of China ( Zhanghe Formation)
  • Yuanmousaurus jiangyiensis

Yuanmousaurus is a genus of sauropod dinosaur from the Middle Jurassic of China. So far, a single fragmentary skull -less skeleton is only known that was discovered in the layers of Zhanghe lineup in Yuanmou in Yunnan Province. Yuanmousaurus was an original representative of the sauropods, in a recent study, the genus within the Mamenchisauridae is classified. Yuanmousaurus was scientifically described with the single species, Yuanmousaurus jiangyiensis 2006.


With a body length of approximately 17 meters, it is a great representative of the sauropods. As with other members of this dinosaur group was characterized by the appearance of a very long neck. The few surviving remnants of the neck have cervical vertebra of the extended type, as it is typical for representatives of Mamenchisauridae, suggesting that the neck compared with other sauropods may have been particularly long. The front legs were longer than in the short-necked Shunosaurus in relation to the hind legs, but shorter than in Omeisaurus - so the length ratio between humerus and femur is about 0.72, while it is at Shunosaurus 0.56 and Omeisaurus about 0.80.

For scientific diagnosis valuable features are found mainly in the vertebrae: So the vertebral arches reported for example, three lateral cavities, while in the related Omeisaurus no such cavities were present.


Yuanmousaurus deemed to be an original representative of Eusauropoda and is outside the Neosauropoda, which includes all advanced sauropods, classified. In the original description this species will be provided to Euhelopodidae; this group, however, is very controversial because of the unclear systematic position of Euhelopus. Sekiya (2011) writes Yuanmousaurus the Mamenchisauridae to, along with Mamenchisaurus, Tienshanosaurus and Chuanjiesaurus.

History of discovery and discovery

The only skeleton was recovered in May 2000 by a team from the Institute of Cultural Relics and Archaeology of Yunnan Province. The site is located in the municipality Jiangyi in Yuanmou county, whereupon the scientific genus and species name has ( Yuanmousaurus jiangyiensis ). The skeleton includes vertebrae ( the fragment of a cervical vertebra, 9 vertebrae, three sacral vertebrae, 7 lumbar vertebrae ), bones of the forelimbs ( humerus, ulna, radius ), an ilium, and bones of the hind legs ( femur, tibia, fibula, talus and a claw). The fossils are archived in the collection of Yuanmou Museum under the copy number YMV 601.