Abstract
A non-hadrosaurid hadrosauroid, Qianjiangsaurus changshengi gen. et sp. nov., is named and described here based on an incomplete, partially articulated skeleton from the top of the Upper Cretaceous Zhengyang Formation in Qianjiang District, Chongqing Municipality, southwest China. The skeleton displays a transitional morphology between non-hadrosaurid hadrosauroids and hadrosaurids. The diagnosis of the taxon is therefore defined as a unique combination of characters, including a series of plesiomorphic features typical of non-hadrosaurid hadrosauroids, some apomorphic features common among hadrosaurids but rarely reported in non-hadrosaurid hadrosauroids, and a probable autopomorphy, namely the fan-shaped prepubic process of the pubis strongly anteroposteriorly constricted and dorsoventrally expanded, with the length/height ratio of ∼0.79. Phylogenetic analysis recovers a sister-taxon relationship between Qianjiangsaurus and Plesiohadros outside of Hadrosauridae, and the clade consisting of the two taxa is positioned higher on the tree than Gobihadros and Gilmoreosaurus, but below the clade of Telmatosaurus + Tethyshadros, Eotrachodon and Zhanghenglong. Combining the morphological data with the phylogenetic topology identifies Q. changshengi as a late-branching non-hadrosaurid hadrosauroid. Given that the age assemblage of the eight hadrosauroids closely related to Qianjiangsaurus in phylogeny spans the Santonian–early Maastrichtian time interval, the top of the Zhengyang Formation, from which Qianjiangsaurus is recovered, is possibly restricted to the late Late Cretaceous in age. Hierarchical clustering of twelve hadrosauroid-bearing dinosaur assemblages from the Late Cretaceous deposits of Asia shows a strong correlation between the Zhengyang Formation and the Djadokhta and Baruungoyot formations in Mongolia that supports coeval interchange of dinosaur faunas across East Asia.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
