Scientists have named and described a new genus of basal iguanodontian from the Xinlong Formation of southern China. The dinosaur has been named Napaisaurus guangxiensis. It is the first, basal iguanodontian taxa described from southern China.

Fossils Found in 2020

Partial hip bones (a right ilium and a right ischium) from a single individual animal were discovered in 2020 from excavations undertaken in strata associated with the Aptian-aged, Xinlong Formation of Napai Basin, Fusui County, Guangxi Zhuang Autonomous Region, South China. The dinosaur’s name translates as Napai Basin lizard from Guangxi and its discovery adds to the dinosaur biota (sauropods, spinosaurids and carcharodontosaurids) associated with the Xinlong Formation.

Team members at Everything Dinosaur, estimate that based on the partial hip bones, the Napaisaurus specimen would have been around four metres in length.

Comparing Dinosaur Biotas from China and North-eastern Thailand

The official journal publication announcing the discovery of this new Early Cretaceous herbivore was published earlier this year, but it was made available on-line in 2021.

The fossils permit an iguanodontian to be added to the dinosaur biota associated with the Xinlong Formation and it provides important evidence helping palaeontologists to better understand the relationship between the Lower Cretaceous fossils of the Napai Basin (Xinlong Formation) and those associated with contemporaneous deposits from northern China and the Khorat Group of north-eastern Thailand. Specifically, the naming of Napaisaurus adds a definitive iguanodontian to the Xinlong Formation biota, thus permitting a more detailed comparison with the ornithischian dinosaurs associated with the Aptian-aged Khok Kruat Formation (the uppermost member of the Khorat Group), from which several iguanodontian ornithopods have been described (Ratchasimasaurus, Siamodon, Sirindhorna).

The scientific paper: “First new genus and species of basal iguanodontian dinosaur (Ornithischia: Ornithopoda) from southern China” by S. Ji and P. Zhang published in Acta Geoscientica Sinica.