Morphotype and Multivariate Analysis of the Occlusal Pattern of the First Lower Molar in European and Asian Arvicoline Species (Rodentia, Microtus, Alexandromys)

Abstract

We studied the morphotypic variation of the occlusal pattern of m1 in 13 arvicoline species (genera Microtus and Alexandromys). As a result, 22 m1 morphotypes were identified. In Alexandromys, five morphotypes of m1 were found, while in Microtus only seven. The morphological diversity of m1 morphotypes (H) in voles of the genus Microtus is significantly lower compared to Alexandromys. The largest number of m1 morphotypes and the highest morphological diversity of m1 were revealed in the Mongolian vole (14 morphotypes and H = 2.134), while the lowest values (two morphotypes and H = 0.285) occur in the population of M. levis from Orlov Island. An attempt of ecological and taxonomical interpretation of interspecific differences was made based on the m1 morphotypes.