title: A new basal ankylosaurid (Dinosauria: Ornithischia) from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China.
abstract: A new ankylosaurid, Chuanqilong chaoyangensis gen. et sp. nov., is described here based on a nearly complete skeleton from the Lower Cretaceous Jiufotang Formation of Baishizui Village, Lingyuan City, Liaoning Province, China. Chuanqilong chaoyangensis can be diagnosed on the basis of two autapomorphies (glenoid fossa for quadrate at same level as the dentary tooth row; distally tapering ischium with constricted midshaft) and also a unique combination of character states (slender, wedge-like lacrimal; long retroarticular process; humerus with strongly expanded proximal end; ratio of humerus to femur length  = 0.88). Although a phylogenetic analysis places Chuanqilong chaoyangensis as the sister taxon of the sympatric Liaoningosaurus near the base of the Ankylosauridae, the two taxa can be distinguished on the basis of many features, such as tooth morphology and ischial shape, which are not ontogeny-related. Chuanqilong chaoyangensis represents the fourth ankylosaurid species reported from the Cretaceous of Liaoning, China, suggesting a relatively high diversity in Cretaceous Liaoning.
authors.affiliation: Faculty of Earth Sciences, China University of Geosciences (Wuhan), Wuhan, China; Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Fenglu
authors.initials: F
authors.lastname: Han
authors.affiliation: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Paleontological Institute, Shenyang Normal University, Shenyang, China.
authors.forename: Dongyu
authors.initials: D
authors.lastname: Hu
authors.affiliation: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Earth Sciences, Natural History Museum, London, United Kingdom.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Barrett
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002681:China; D025061:Dinosaurs / Q000033:anatomy & histology*; D005580:Fossils; D005843:Geography; D007512:Ischium / Q000033:anatomy & histology; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology; D013045:Species Specificity; D014070:Tooth / Q000033:anatomy & histology