Yongjinglong was first described and named by Li-Guo Li, Da-Qing Li, Hai-Lu You and Peter Dodson in 2014 and the type species is Yongjinglong datangi.
The generic name is derived from the name of the historical Yongjing County, near where the holotype of Yongjinglong and numerous dinosaur track fossils were collected, and from long, meaning "dragon" in Chinese.
The specific name, datangi, honors the Tang dynasty and also Mr. Zhi-Lu Tang from the IVPP, for his contributions to the study of dinosaurs.

Yongjinglong is known solely from the holotype GSGM ZH(08)-04, a partial postcranial skeleton and three teeth, currently housed at the Gansu Geological Museum, Gansu Province.
The postcranial remains include one fragmentary dorsal rib, the left scapulocoracoid, the right ulna and radius, as well as eight presacral vertebrae including one caudal cervical vertebra, four cranial dorsal vertebrae, and three articulated middle dorsal vertebrae.
It represents a subadult individual.
GSGM ZH(08)-04 was by Li Daqing and You Hailu discovered in 2008 beside the G75 Highway, less than a kilometer from the quarries of Daxiatitan and Huanghetitan liujiaxiaensis, near Zhongpu.
It was collected from the upper Hekou Group, in the southeastern part of the Lanzhou-Minhe Basin, Gansu Province, dating to the Early Cretaceous.
Yongjinglong was first described and named by Li-Guo Li, Da-Qing Li, Hai-Lu You and Peter Dodson in 2014 and the type species is Yongjinglong datangi. The generic name is derived from the name of the historical Yongjing County, near where the holotype of Yongjinglong and numerous dinosaur track fossils were collected, and from long, meaning "dragon" in Chinese. The specific name, datangi, honors the Tang dynasty and also Mr. Zhi-Lu Tang from the IVPP, for his contributions to the study of dinosaurs.
Yongjinglong is known solely from the holotype GSGM ZH(08)-04, a partial postcranial skeleton and three teeth, currently housed at the Gansu Geological Museum, Gansu Province. The postcranial remains include one fragmentary dorsal rib, the left scapulocoracoid, the right ulna and radius, as well as eight presacral vertebrae including one caudal cervical vertebra, four cranial dorsal vertebrae, and three articulated middle dorsal vertebrae. It represents a subadult individual. GSGM ZH(08)-04 was by Li Daqing and You Hailu discovered in 2008 beside the G75 Highway, less than a kilometer from the quarries of Daxiatitan and Huanghetitan liujiaxiaensis, near Zhongpu. It was collected from the upper Hekou Group, in the southeastern part of the Lanzhou-Minhe Basin, Gansu Province, dating to the Early Cretaceous.
Yongjinglong