Chuanqilong (meaning "legendary dragon") is a monospecific genus of basal ankylosaurid dinosaur from the Liaoning Province, China that lived during the Early Cretaceous (late Barremian to Aptian stage, 122.0 to 118.9 Ma) in what is now the Jiufotang Formation. The type and only species, Chuanqilong chaoyangensis, is known from a nearly complete skeleton with a skull of a juvenile individual. It was described in 2014 by Fenglu Han, Wenjie Zheng, Dongyu Hu, Xing Xu, and Paul M. Barrett. Chuanqilong shows many similarities with Liaoningosaurus and may represent a later ontogenetic stage of the taxon.
Chuanqilong was a medium-sized ankylosaur, with an estimated length of 4.5 metres (14.8 feet), although it has been suggested that it would have been larger due to the immature age of the type specimen. It had a triangular skull and a neck that was protected by bands of osteoderms known as cervical half rings. The rest of the body was covered in osteoderms and ossicles of various shapes and sizes. Unlike derived ankylosaurids, the end of its tail lacked a club. Like other ankylosaurids, it was quadrupedal with robust forelimbs and hindlimbs.
A nearly complete skeleton was collected by local farmers from a single quarry in the Liaoning Province, China. The skeleton was recovered from the Jiufotang Formation which dates to the late Barremian to Aptian stages of the Early Cretaceous period, 122.0 to 118.9 Ma. The specimen was named and described in 2014 by Fenglu Han, Wenjie Zheng, Dongyu Hu, Xing Xu, and Paul M. Barrett. The holotype specimen, CJPM V001, consists of a nearly complete skull and skeleton, with only the distal portion of the caudal series missing, and represents a juvenile individual. The authors noted that the specimen was at a more advanced ontogenetic stage than the specimens of the sympatric Liaoningosaurus based on the larger size of the type specimen, the size of the orbit and the tooth count. The specimen is preserved two-dimensionally, with only the ventral side being visible. Most of the skull is compressed dorsoventrally and most of the vertebral column is disarticulated, while the limbs are preserved in articulation. The type specimen is currently housed at the Chaoyang Jizantang Paleontological Museum, while a cast of the specimen (IVPP FV 1978) is housed at the Institute of Vertebrate Paleontology and Paleoanthropology.[1]
The generic name, Chuanqilong, is derived from the Chinese words "Chuanqi" (legendary), in reference to the abundance of fossils of western Liaoning, and "long" (dragon). The specific name, chaoyangensis, refers to the broader geographical area which encompasses the type locality.[1]
In 2014, the impressions of a scapulocoracoid and humerus belonging to an indeterminate ankylosaur with an estimated body length of 6.0-8.6 metres (19.7-18.2 feet) were described from the Jiufotang Formation and, at the time, was the first ankylosaur described from the formation.[2] A Canadian Society of Vertebrate Palaeontology abstract book that was published in 2019 mentioned that the type and only known specimen of Chuanqilong actually represented an adult individual, in contrast to the interpretation of Han et al. (2014), and may have been Liaoningosaurus at a different and later ontogenetic stage.[3]
Han et al. (2014) gave Chuanqilong an estimated length of 4.5 metres (14.8 feet). However, the authors suggested that it could have reached larger sizes as the type specimen represents a juvenile individual.[1]