Data from: Systematics and phylogeny of Vasseuromys (Mammalia, Rodentia, Gliridae) with a description of a new species from the late Miocene of eastern Europe

Vasseuromys is a species‐rich genus of small‐ to medium‐sized glirids spanning the latest Oligocene to late Miocene of Europe and western Asia. Despite extensive discoveries over the past 50 years, little phylogenetic work has been done on Vasseuromys. This study presents the first phylogenetic analysis of the genus that includes all the described species and a new taxon Vasseuromys tectus sp. nov. from the late Miocene of eastern Europe, providing the first insights into the evolutionary relationships within the clade. Results suggest that the genus is clearly paraphyletic. Two strongly supported genus‐level clades are recognized within ‘Vasseuromys’: a restricted Vasseuromys clade (containing the three species, V. pannonicus, V. rugosus and V. tectus) and the Glirulus clade that includes ‘Vasseuromys’ duplex. The remaining ‘Vasseuromys’ species are found to constitute a set of paraphyletic taxa, with the polyphyletic ‘Ramys’ nested within it. The genus Gliruloides is synonymized with Glirulus. Vasseuromys tectus sp. nov. is the most derived member of the genus in having a greater number of cheek teeth ridges including constantly present anterotrope, centrotrope, second prototrope on M1–2, third metatrope on M2, two to three posterotropids on p4 and strong ectolophids on lower molars. The results of the study confirm a European origin for Vasseuromys while suggesting that the late Miocene species of the genus dispersed from the east in the early Turolian.瓦瑟鼠属（Vasseuromys）是一个物种丰富的中小型睡鼠科（Gliridae）啮齿类属，生存时代涵盖欧洲与西亚的渐新世晚期至中新世晚期。尽管过去50年间已有大量化石发现，但针对瓦瑟鼠属的系统发育研究仍较为匮乏。本研究首次对该属开展涵盖所有已命名物种及1个新分类单元——产自东欧中新世晚期的Vasseuromys tectus sp. nov.（新种）的系统发育分析，首次揭示了该演化支内部的演化关系。分析结果显示该属明显为并系群。在广义“Vasseuromys”中，可识别出两个得到强力支持的属级演化支：限定范围的瓦瑟鼠属演化支（包含V. pannonicus、V. rugosus与V. tectus三个物种），以及包含“Vasseuromys” duplex的睡鼠属（Glirulus）演化支。其余的“Vasseuromys”物种被证实为一组并系类群，且多系的“Ramys”类群嵌套于其中。Gliruloides属被归为睡鼠属（Glirulus）的同物异名。Vasseuromys tectus sp. nov.是该属中最为特化的物种，其颊齿脊数量更多，具体包括M1-2上恒定存在的前尖脊（anterotrope）、中尖脊（centrotrope）、第二原尖脊（second prototrope），M2上的第三后尖脊（third metatrope），p4上的2~3个后尖脊（posterotropids），以及下臼齿上发达的外脊（ectolophids）。本研究结果证实瓦瑟鼠属起源于欧洲，同时表明该属的中新世晚期物种是在图罗利昂早期（Turolian）从东部扩散而来的。