Bayannurosaurus is a non-hadrosauriform ankylopollexianornithopod described in 2018 by Xuet al from the Barremian (Early Cretaceous) found in the Bayin-Gobi Formation of China.[1] The genus includes a new species Bayannurosaurus perfectus. A phylogenetic analysis of Bayannurosaurus indicates that it is more derived than Hypselospinus but less derived than Ouranosaurus just outside of Hadrosauriformes. It had a skull length of 80 cm, making it a mid-sized iguanodont.[1] By comparison Ouranosaurus had a 67 cm skull, and a length of 7 to 8.3 meters (23 to 27 feet). Though inexact, if this is used as a comparison to scale to, Bayannurosaurus would be 8.3 to 10 meters (27 to 33 feet) long.
^ abXu, Xing; Tan, Qingwei; Gao, Yilong; Bao, Zhiqiang; Yin, Zhigang; Guo, Bin; Wang, Junyou; Tan, Lin; Zhang, Yuguang; Xing, Hai (2018). "A large-sized basal ankylopollexian from East Asia, shedding light on early biogeographic history of Iguanodontia". Science Bulletin. doi:10.1016/j.scib.2018.03.016.
