Qijianglong

Qijianglong Temporal range: Late Jurassic
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Suborder:	†Sauropodomorpha
Family:	†Mamenchisauridae
Genus:	†Qijianglong Xing et al., 2015
Type species
Qijianglong guokr Xing et al., 2015

Qijianglong is a monospecific genus of herbivorous mamenchisaurid sauropod dinosaur of the Late Jurassic of China.^[1]

A vertebra of Qijianglong was first discovered in the early 1990s by farmer Cai Changming of Heba village, Sechuan, in his backyard. Work at a nearby construction site at Qijiang City uncovered a rich fossil quarry in 2006. Its excavation caused an examination of the earlier find which led to the discovery of a skeleton. In 2015, the type species Qijianglong guokr was named and described by Xing Lida, Tetsuto Miyashita, Zhang Jianping, Li Daqing, Ye Yong, Toru Sekiya, Wang Fengping and Philip John Currie. The generic name combines the district Qijiang with Mandarin long, "dragon". The specific name guokr, "nutshell", is that of a Chinese scientific social network.^[1]

The holotype QJGPM 1001 was found in a layer of the Suining Formation which dates from the Late Jurassic and is perhaps Oxfordian in age. It consists of a partial skeleton with skull. It includes the rear of the skull, a partial right lower jaw, a complete series of seventeen neck vertebrae, the first six back vertebrae, ribs, the probable tenth tail vertebra, a series of twenty-eight rear tail vertebrae, chevrons, the left pubic bone and two upper pedal phalanges. It likely represents a juvenile individual, large but immature.^[1]

The holotype of Qijinaglong was about fifteen meters long and had a long neck. The describing authors established several distinguishing traits among which four autapomorphies. On the lower braincase the processus basipterygoideus has the form of a plate, is oriented along the body axis, and has an additional boss parallel to the tubera basilaria. The neck vertebrae have rear joint processes, postzygapophyses that next to their normal facets show on the outside an additional finger-shaped extension, stiffening the neck in the horizontal plane but allowing vertical movement. The rear neck vertebrae have pneumatopores, pneumatic openings, in the depression between the diapophysis, the upper rib joint process, and the neural spine. The pubic bone has a concave front edge, curving so strongly that its lower end is more directed to the front than to below.^[1]

Qijianglong was placed in the Mamenchisauridae, in a relatively basal position but above Omeisaurus tianfuensis in the evolutionary tree.^[1]

References