This study was financially supported by the National Natural Science Foundation of China (41272022), the Central Public-interest Scientific Institution Basal Research Fund for the Chinese Academy of Geological Sciences (No. JB1504), and China Geological Survey (grant No. DD20160201). SLB’s work on theropod phylogenetics has been supported by NSF DEB 1110357, an NSF GRF, Columbia University, the American Museum of Natural History, and Mark Norell. His lab is currently funded by a Marie Curie Career Integration Grant (EC 630652).
A new troodontid dinosaur, Daliansaurus liaoningensis gen. et sp. nov., is erected based on a nearly complete specimen from the Lower Cretaceous Yixian Formation of Beipiao City, Liaoning Province, China. This well preserved skeleton provides important new details of the anatomy for Liaoning troodontids, and gives new insight into their phylogenetic relationships and evolution. Daliansaurus is distinguished from other troodontids by an enlarged ungual on pedal digit IV, which is approximately the same size as the sickle-shaped second ungual, and is differentiated from other Liaoning troodontids by a number of characters of the skull, manus, pelvis, and hindlimb. A phylogenetic analysis recovers Daliansaurus within a subclade of Liaoning troodontids that also includes Sinovenator, Sinusonasus, and Mei. We erect a name for this group—Sinovenatorinae—and argue that it reflects a localized radiation of small-bodied troodontids in the Early Cretaceous of eastern Asia, similar to previously recognized radiations of Liaoning dromaeosaurids and avialans. As more Liaoning theropods are discovered, it is becoming apparent that small, feathered paravians were particularly diverse during the Early Cretaceous, and future work is needed to clarify how this diversity arose, which species coexisted, and how these numerous species partitioned niches.
SHEN Caizhi, Lü Junchang, LIU Sizhao, Martin KUNDRáT, Stephen L. BRUSATTE, GAO Hailong.2017. A New Troodontid Dinosaur from the Lower Cretaceous Yixian Formation of Liaoning Province, China[J]. Acta Geologica Sinica(),91(3):763-780Copy