First fossil evidence for a new frog from the Early Cretaceous of the Jiuquan Basin, Gansu Province, north-western China

Based on a well-preserved incomplete skeleton, a new frog, Gansubatrachus qilianensis gen. et sp. nov., is described from the Lower Cretaceous Zhonggou Formation of Jiuquan Basin, Gansu Province, north-western China. This species differs from other frogs in a unique combination of characteristics, such as a robust and non-bifurcated alary process on the premaxilla, a `V'-shaped parahyoid, a paired sphenethmoid, eight presacral vertebrae, three pairs of free ribs, and unexpanded sacral diapophyses. Phylogenetic analysis based on parsimony suggests that Gansubatrachus is a basal Lalagobatrachia. This discovery of a new frog fossil from the Early Cretaceous of north-west China expands the diversity of fossil frogs in East Asia and provides new material for further studies on the distribution and evolutionary history of Cretaceous Asian anurans.