内蒙古鄂尔多斯地区早白垩世新的翼龙类化石

发现于内蒙古鄂托克旗召稍早白垩世罗汉洞组的一件不完整翼龙类下颌标本,以下颌愈合部长且平直、齿骨侧嵴发育、近圆形齿窝沿侧嵴之上的齿骨侧面上半部分自前向后呈直线排列、齿窝直径(2~2.5 mm)前后变化较小、相邻齿窝的间距约为齿窝直径的一半、下颌牙齿密度为3枚/cm等特征,可归入梳颌翼龙科(Ctenochasmatidae),且代表一新属种——郝氏鄂托克翼龙Otogopterus haoae gen.et sp.nov.。该化石是继鄂托克旗新召准噶尔翼龙科的平颌鄂尔多斯翼龙Ordosipterus planignathus之后在内蒙古鄂尔多斯地区发现的第2件确切翼龙类材料,丰富了这一地区早白垩世脊椎动物群的组成。该翼龙也是继甘肃庆阳环河翼龙Huanhepterus quingyangensis之后在鄂尔多斯盆地发现的第2种梳颌翼龙科化石,进一步扩大了鄂尔多斯盆地梳颌翼龙科的地理分布范围,同时表明鄂尔多斯盆地是继辽宁西部之后梳颌翼龙科在中国的又一重要分布区。

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.