separate cervical osteoderm plates. Between the proximal end of the left ulna and radius is a small triangular osteoderm that has a wide base and tapers distally. Present near the left ischium is an oval osteoderm that is sharply keeled along the midline. Preserved over the entirety of the body are a diverse range of osteoderms and ossicles that are small and irregular. Classification Han et al. (2014) originally found Chuanqilong to be a basal ankylosaurid that was sister taxon to Liaoningosaurus. The authors noted that only two unambiguous synapomorphies supported its close relationship to Liaoningosaurus, which are the presence of an antorbital fossa and a ventrally oriented scapula glenoid. The authors also noted that, although both taxa are represented by juvenile specimens and are sister taxa, Chuanqilong can be differentiated from Liaoningosaurus based on a number of characteristics such as the differences in the metatarsus to metacarpus length ratio and the morphology of the cheek tooth crown. Cladistic analyses conducted by Arbour & Currie (2015) recovered Chuanqilong as either being within a polytomy with other basal ankylosaurids or as sister taxon to Cedarpelta, a position also recovered by Arbour et al. (2016). Analyses conducted by Arbour & Evans (2017), Zheng et al. (2018) and Park et al. (2019) similarly placed Chuanqilong within a polytomy with other basal ankylosaurids, although the inclusion of certain taxa such as Aletopelta within the internal node varied. Rivera-Sylva et al. (2018) also recovered it within a polytomy in a strict consensus tree, but it was also recovered it as sister taxon to Cedarpelta in a 50% majority rule tree. Contrary to other analyses, Frauenfelder et al. (2022) found Chuanqilong to be within a clade including Liaoningosaurus and Cedarpelta outside of Ankylosauridae and Nodosauridae. In 2019, an abstract suggested the possibility that Chuanqilong and Liaoningosaurus may represent the same species but at different ontogenetic stages. Below is a reproduced phylogenetic analysis from Arbour & Currie (2015). Paleoenvironment The remains of Chuanqilong were uncovered from the Jiufotang Formation of the Jehol Group. The formation is composed of mudstones, siltstones, shales, sandstones and tuffs, and overlies the Yixian Formation. Recent secondary ion mass spectrometry (SIMS) zircon U-Pb analyses suggest that the formation dates to the late Barremian to Aptian stages of the Early Cretaceous, ca. 122.0–118.9 Ma. Both the Yixian and Jiufotang Formations represent freshwater lacustrine environments that lacked rivers as well as many other variable features