Geographic Variability of the Molars of Red Voles (<i>Clethrionomys Rutilus</i> Pallas, 1779) (Rodentia, Cricetidae) of the Tyumen Region
This article presents dimensional characteristics and structures of the masticatory surface of molar teeth of the red voles in the Tyumen Region. The authors identify the geographic variability of the M<sub>1</sub> and M<sup>3</sup> teeth masticatory surface's structure and the dimensional characteristics of the molars of the red voles. The paper shows the adaptive value of the structure of the molars' masticatory surface in relation to the power, i. e., it is a natural complication of the M<sub>1</sub> and M<sup>3</sup> teeth masticatory surface for the red voles when moving to the North. Geographic variability of individual dimensional characteristics of molars is traced. While moving northward dimensions, red voles' teeth are decreasing, though also the Northern forest-steppe is characterized by a decrease in the size of individual teeth. This is probably due to the increase in the share of forages (seeds and grass) in the ration type.