Plesiosaur specimens from the Upper Jurassic of European Russia are mainly referable to the genus Colymbosaurus Seeley, 1874, based on elongated propodials with extensive posterodistal expansion, and relatively short mid-cervical vertebrae. However, a historical specimen described by Bogolubov (1911) and subsequently revised as Plesiosauria indet. (Storrs et al. 2000) was hitherto the only and ambiguous evidence for the presence of Colymbosaurus in the Upper Jurassic of European Russia. Here, we provide descriptions of several specimens from the Volgian of European Russia referable to Colymbosaurus sp. and Colymbosaurinae indet. The presence of Colymbosaurus in the Late Jurassic (Volgian/Tithonian) of the Middle Russian Sea makes it possible to formulate hypotheses on herpetophauna exchange between NW Europe, Svalbard and European Russia. Found only in these basins, Colymbosaurus is a unifying element of marine herpetofauna in the Panboreal palaeobiogeographic superrealm.

中文翻译：

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欧洲俄罗斯上侏罗世的鞘龙类及其对海洋爬行动物的古生物地理学的意义

来自欧洲俄罗斯上侏罗世的蛇颈龙标本主要指的是Colymbosaurus Seeley属，1874年，其基础是伸长的后肢，后大范围的扩张和相对较短的中颈椎。但是，Bogolubov（1911）所描述的历史标本后来被修订为蛇颈龙。（Storrs等，2000）是迄今为止在欧洲俄罗斯上侏罗统中存在鞘龙的唯一且模棱两可的证据。在这里，我们提供了一些来自欧洲俄罗斯Volgian的标本，它们与Colymbosaurus sp。有关。和Colymbosaurinae indet。鞘龙的存在俄罗斯中海的侏罗纪晚期（Volgian / Tithonian）的研究使人们有可能对欧洲西北部，斯瓦尔巴特群岛和欧洲俄罗斯之间的食草动物交换提出假设。鞘龙仅在这些盆地中发现，是Panboreal古生物地理超领域中海洋爬虫类动物的统一元素。