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. http://zoobank.org/urn:lsid:zoobank.org:pub:A80B417A-F9C6-4704-B473-FBBA6CDC8C2B基于一具保存完好的不完整骨架，我们对产自中国西北甘肃省酒泉盆地下白垩统中沟组的蛙类新属新种祁连山甘肃蟾（Gansubatrachus qilianensis gen. et sp. nov.）进行了正式记述。该种与其他蛙类的区别在于其独特的特征组合：前颌骨具粗壮且不分叉的翼状突、呈‘V’形的副舌骨、成对的蝶筛骨、8枚骶前椎、3对游离肋以及未膨大的骶骨横突。基于简约法的系统发育分析显示，甘肃蟾属（Gansubatrachus）属于基部拉加蟾类（Lalagobatrachia）。此次在中国西北早白垩世地层中发现的蛙类新化石，丰富了东亚化石蛙类的多样性，同时为进一步研究白垩纪亚洲无尾类的分布与演化历史提供了全新的研究材料。http://zoobank.org/urn:lsid:zoobank.org:pub:A80B417A-F9C6-4704-B473-FBBA6CDC8C2B