A new Early Cretaceous pterosaur from the Ordos region, Inner Mongolia

The western Ordos region in Inner Mongolia, including Hanggin Banner and Otog Banner, is one of the most important localities yielding the Early Cretaceous Psittacosaurus Fauna across northern China. No pterosaur material had been formally depicted until Ordosipterus planignathus was named and described in the early 2020. Here, we report a new partial pterosaur mandibular symphysis discovered at the Zhaoshao site in the Luohandong Formation in Otog Banner. Its mandibular symphysis is long and straight and bears a developed lateral ridge that divided the dentary lateral side into the upper and lower parts. Nearly round dentary alveoli of each side lie just above the lateral ridge along a straight line anteroposteriorly. The diameters of alveoli (2-2.5 mm) vary slightly from rostral to caudal. The distance between the adjacent alveoli is about half the diameter of either alveolus. The tooth density is 3 teeth per centimeter. This pterosaur could be assigned to the family Ctenochasmatidae, it represents a new taxon-Otogopterus haoae gen.et sp.nov. The generic name refers to the type locality (Otog Banner) of this pterosaur, and the species name is in honour of Prof. Hao Yichun, who made outstanding contributions on the Mesozoic paleontology and stratigraphy in China. This new fossil is the second definitive pterosaur kind in the Inner Mongolian Ordos region following Ordosipterus planignathus, further enriching the components of the Early Cretaceous vertebrate fauna in this region. This pterosaur is also the second ctenochasmatid taxon in the Ordos Basin, after Huanhepterus quingyangensis from eastern Gansu Province. The new finding enlarged the geographical distribution of ctenochasmatid pterosaurs in the Ordos Basin and revealed the Ordos Basin to be another important distribution area of Ctenochasmatidae in China. © 2020, Editorial Office of Earth Science Frontiers. All right reserved.