作者：Sevket SEN, Margarita A. ERBAJEVA

摘要：报道了产自贝加尔湖区中中新世Aya洞穴的戈壁古仓鼠(Gobicricetodon)一新种G. filippovi sp. nov.。该种以较小的个体和牙齿上的一些原始特征区别于该属其他种类。先前的研究认为Gobicricetodon与近古仓鼠(Plesiodipus)同属于戈壁古仓鼠亚科，然而，它们与欧亚大陆一些置于古仓鼠亚科(Cricetodontinae)内的属在牙齿形态上的高度相似性表明其亲缘关系。为了理清Gobicricetodon和Plesiodipus与Cricetodontinae之间的系统发育关系，也为了阐明这一类群属和属以上级别的分类，使用Mesquite 2.72软件作了分支系统学分析。结果获得了3个主要的分支类群，Gobicricetodon, Plesiodipus, Mixocricetodon和Tsaganocricetus同属于其中的一个分支。令人惊奇的是，一些欧洲古仓鼠(Cricetodon)的种，包括其模式种C. sansaniensis也在这一分支内。此外，支序分析还显示上述类群可能起源于欧亚大陆西部的Cricetodon支系。分析的另一项结果指示，Cricetodon属显然是一个多系类群，需要进一步划分为多个属。

关键词：贝加尔湖，中中新世，哺乳动物，古仓鼠亚科，系统发育

卷期：49卷 03期

A new species of Gobicricetodon Qiu, 1996 (Mammalia, Rodentia, Cricetidae) from the Middle Miocene Aya Cave, Lake Baikal

Sevket SEN, Margarita A. ERBAJEVA

Abstract  A new species of Gobicricetodon is described from the middle Miocene of Aya Cave in the Lake Baikal area. It differs from the other species of this genus by its smaller size and some primitive characters of the dentition. In previous studies, Gobicricetodon together with Plesiodipus has been considered as belonging to a distinct Subfamily Gobicricetodontinae. However, great similarities of dentition suggest affinities with several other Eurasian genera grouped in the subfamily Cricetodontinae. To clear up phylogenetic relationships of Gobicricetodon and Plesiodipus with Cricetodontinae, and to enlighten generic and supra-generic systematics of this group, a cladistic analysis using Mesquite 2.72 was done. It reveals three main clades. One of them groups Gobicricetodon and Plesiodipus together with the genera Mixocricetodon and Tsaganocricetus and, surprisingly, with some European species of Cricetodon, including its type species C. sansaniensis. In addition, this analysis suggests an origin for the group from within a Cricetodon-stock of western Eurasia. Another result of this study is that the genus Cricetodon is apparently polyphyletic and needs division into several genera.
Key words  Lake Baikal; Middle Miocene; Cricetodontinae, Mammalia; phylogeny