Analysis of shape and size variation of the first lower molar in Far-Eastern grey voles of genus Alexandromys (Rodentia: Cricetidae) from Russian fauna using geometric morphometrics

Abstract

The variation of quantitative characters of the first lower molar was analysed in nine species of Far-Eastern voles Alexandromys from Russian fauna. Canonical variation analysis revealed that main differences were associated with oeconomus-like fusion, and clearly differentiates A. oeconomus, A. mongolicus and A. gromovi from other species. The results of UPGMA cluster analysis based on the average Procrustes distances did not agree with recent molecular studies. Discriminant analysis of Procrustes coordinates of 19 landmarks showed that the percentage of correct species classifications of samples vary from 50% to 100%. Linear measurements together with shape features can be used for identification of the following species: A. oeconomus, A. mongolicus, and A.sachalinensis. Shape of enamel loops of the first lower molar of Far-Eastern grey voles can be used for species identification, but not for phylogenetic analysis.