The Eocene whiptail stingrays of the family Dasyatidae from the Bolca Lagerstätte, NE Italy, are revised herein in detail. The analysis of the anatomical and morphometric features allows us to identify the species “Dasyatis” zigni (Molin, 1861) as a junior synonym of “D.” muricatus (Volta, 1796), and to assign it to the new genus Tethytrygon gen. n. This new taxon exhibits a unique combination of features (e.g., rhombic disc wider than long, elongated tail folds fail to reach the tip of the tail, thorns absent, single serrated tail sting, “caniniform” teeth on upper jaw, tooth crown ornamentation absent, 175–179 vertebrae, 108–117 pectoral radials, 24–27 pelvic radials and other features of clasper anatomy) that clearly support its attribution to the subfamily Neotrygoninae of the stingray family Dasyatidae. The morphological and phylogenetic affinities of Tethytrygon gen. n. with the living neotrygonines (Neotrygon and Taeniura) suggest a close association of this taxon with the tropical shallow‐water habitats hypothesized for the Bolca palaeoenvironment during the early Eocene. Moreover, the analysis of the fossil occurrences of the neotrygonines provides new insights into the role of the Tethys for the origin and evolutionary history of certain whiptail stingrays.

中文翻译：

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意大利 Bolca Lagerstätte 始新世鞭尾黄貂鱼（Myliobatiformes，Dasyatidae）的重新评估

来自意大利东北部 Bolca Lagerstätte 的始新世鞭尾黄貂鱼科 Dasyatidae 在本文中进行了详细修改。对解剖和形态特征的分析使我们能够将“Dasyatis”zigni（Molin，1861）物种识别为“D”的初级同义词。muricatus (Volta, 1796)，并将其归入新属 Tethytrygon gen。名词 这个新的分类单元表现出独特的特征组合（例如，菱形盘宽大于长，细长的尾褶无法到达尾尖，没有刺，单锯齿状尾刺，上颌上的“犬形”牙齿，缺乏齿冠装饰，175-179 块椎骨，108-117 块胸桡骨，24-27 块骨盆桡骨和扣环解剖学的其他特征）清楚地支持其归属于黄貂鱼科 Dasyatidae 的 Neotrygoninae 亚科。Tethytrygon gen 的形态和系统发育亲缘关系。名词 与现存的新锥虫（Neotrygon 和 Taeniura）的关系表明，该分类单元与始新世早期博尔卡古环境假设的热带浅水生境有密切的联系。此外，对新锥虫化石出现的分析为了解特提斯海对于某些鞭尾黄貂鱼的起源和进化历史的作用提供了新的见解。