Jinchuanloong
Jinchuanloong is an extinct genus of eusauropod sauropod dinosaurs from the Middle Jurassic Xinhe Formation of China. The genus contains a single species, Jinchuanloong niedu, known from a partial skeleton including a nearly complete skull.
Discovery and naming
The Jinchuanloong holotype specimen, JCMF 0132, was discovered as the result of fieldwork conducted in 2017 by Dr. Li Daqing in outcrops of the Xinhe Formation in the Jinchuan District, of Gansu Province in northwest China. The specimen consists of a well-preserved, nearly complete skull and articulated with the first five and 29 of the posteriormost , some of which are preserved with associated. In the approximately gap between the neck and tail, there are preserved impressions of the and. The first three preserved caudals preserve only the. The remaining vertebrae are all articulated, exposed in right lateral view. Unfortunately, the caudal vertebrae were not yet collected at the time of their description in 2025, so protective fences were installed around them in the outcrop they are embedded in.In 2025, Li et al. described Jinchuanloong niedu as a new genus and species of eusauropod dinosaurs based on these fossil remains. The generic name, Jinchuanloong, combines a reference to the type locality in Jinchuan District with the Mandarin Chinese word long, meaning "dragon". The specific name, niedu, combines the Mandarin words nie, meaning "nickel" and du, meaning "city", in reference to Jinchuan's well-known nickel resources.
Description
The holotype skull of Jinchuanloong measures long and tall. It generally resembles the skulls of related taxa such as Mamenchisaurus youngi. In comparison to this taxon and Shunosaurus, the skull of Jinchuanloong appears to have a broader snout in dorsal view, though this may be the result of taphonomic deformation.Jinchuanloong is known only from anteriormost and posteriormost parts of the skeleton, specifically the skull, the beginning of the neck, and the end of the tail. Based on the relative location of these preserved elements, Jinchuanloong is estimated to be long. There is no fusion between the and or the cervical and first preserved caudal vertebrae, which implies the holotype belongs to an individual that was not skeletally mature. Furthermore, the and of the are unfused, and the is large, both raising the possibility that the holotype is a juvenile.