Abstract: New rodent material is described from the Bumbanian Gomphos bed in Earlian Basin,Nei Mongol (Inner Mongolia), China. A new genus and species, Yuanomys zhoui, is named. The new species differs from other Early Eocene rodents in having slim and isolated cusps and conules on cheek teeth and transverse paracone and metacone with steep surfaces facing a broad trigon basin. These features of Y. zhoui to some degree resemble those of alagomyids. Constrained magneto- and biostratigraphically, the occurrence of these rodents indicates that the earliest radiation of rodents with modern aspect probably took place during the period of mid-Paleocene to early Eocene. 

摘要： 描述了内蒙古二连盆地伯姆巴期Gomphos层的啮齿类新材料并命名了一个新属种：周氏原鼠(Yuanomys zhoui)。新属种与其他早始新世的梳趾鼠区别在于颊齿具有纤细且孤立的齿尖和小尖，前尖与后尖横向延伸，面对三角座盆的齿尖面陡直。这些特征在一定程度上与alagomyids类似。依据古地磁与生物地层对比，这些啮齿类的出现表明，现代类型的啮齿类最早的辐射演化，很可能位于中古新世到最早始新世这个时间段中。