Abstract: The anatomy of the masticatory apparatus, movement pattern of mandible and masticatory efficiencies of cheek teeth row during mastication are compared between mandarin vole (Microtus manadarinus) and the common Chinese zokor (Myospalax cansus) to better understand the adaptive mechanism of the two underground rodents. The analysis is based on biomechanical principles as well as quantitative comparisons between thetwo species. The results indicated that the mandibles of both species can freely move forth and back during mastication，suitable to grinding plant fibres, correspondingly，the skull has developed a series of characters to facilitate this movement pattern，such as parallel cheek teethrows，groove-like glenoid fossa and curved occlusal plane of cheek teeth row. Masticatory efficiencies of incisors and molars in both species are almost equal to each other，implying a very similar feeding habit between them.

Key words: Mandarin vole(Microtus mandarinus), Common Chinese zokor(Myospalax cansus), Masticatory apparatus, Function Structure

摘要： 为了解棕色田鼠与甘肃鼢鼠对食物的适应机制, 对它们的咀嚼肌及相关的骨学特征做了比较解剖, 并运用生物力学原理分析下颌运动方式及食物加工过程的咀嚼效率。结果表明, 两个种的下颌的咀嚼均以水平面的前后向运动为主, 研磨加工植物纤维。相应地, 咀嚼肌、牙齿及相关的骨骼形态也具有一系列与此运动方式和功能相适应的结构特征, 如彼此平行的左右侧颊齿列、沟槽状的下颌关节窝以及咬肌的排列位置前移等。此外, 两个种具有几乎相同的门齿切割效率和臼齿咀嚼效率。两个种的上述相似特征与它们有着相似的食物结构是一致的。

关键词: 棕色田鼠, 甘肃鼢鼠, 咀嚼肌, 结构, 功能