UPPER JURASSIC DINOSAUR ASSEMBLAGE IN YUNNAN PROVINCE, PRC

LuFeng, Yunnan Province, People’s Republic of China characteristically contains vertebrate fossils of earliest Jurassic Origin. Best known among these are well-preserved prosauropods that dominate the dinosaur fauna. In an area east and south of LuFeng, near the Village of Lao Chang Qing, (102º 04.586’ E; 24º 58.331’ N), a heavily thrust-faulted area containing a playa lakebed initially thought to be of the Early Jurassic LuFeng Formation was found to contain numerous dinosaur fossils. Ongoing excavation has yielded fossils from several sauropod individuals, numerous turtles, and a single, unidentified, theropod. Work conducted in 1999 yielded sufficient sauropod material to allow identification of the sauropods as Mamenchisaurus. Local authorities decided to leave the fossils in a partially excavated in situ state with the intention of building an educational facility over the site similar to that of Dinosaur National Monument in Utah, USA. This may become problematic, as the fossils contain gypsum and will surely fragment from exposure to repeated wet-dry cycles before the building is completed. To date, 239 sauropod bones have been uncovered, 5 theropod bones, and 5 turtles. Sauropod fossils include an intact sacrum, pubes, ilia, and ischia,, numerous articulated vertebral segments, 5 scapulae, various limb bones, and a manus. The site is the southernmost occurrence known for Mamenchisaurids and contributes to our understanding of species morphology and distribution. The highly derived material indicates an upper Jurassic origin for this formation.