DIVERSITY OF STRUCTURAL VARIANTS OF THE m1 ANTEROKONID IN THE VOLE GENERA <i>STENOCRANIUS</i> AND <i>ALEXANDROMYS</i> (ARVICOLINI, RODENTIA): QUALITATIVE AND QUANTITATIVE APPROACHES

Abstract

75 images of anteroconid morphotypes for five vole species were studied using traditional and GM methods: Stenocranius gregalis, Alexandromys middendorffii, A. mongolicus, A. mujanensis, and A. oeconomus. The morphotypical space is three-dimensional within the framework of the traditional approach, the axes being formed by (1) the complexity of the curve of the lingual and (2) labial sides of the anterior loop, and (3) the number of closed triangles. The total number of morphotypes for four species of Alexandromys is 56, 30 of them having been actualized (the degree of completeness of the morphospace is 53.6%). The thin plate and Procrustean distance analysys were used in the quantitative approach. The distribution of morphotypes in the space of the first two relative deformations, both for individual species and for their complex, corresponds to an arcuate configuration, the first of which is mainly associated with the complication/simplification of the buccal side of the antheroconid, while the second with the bilateral complication/simplification and simultaneous extension/compression of the antheroconid. The part of the potential morphospace that corresponds to a moderately complicated and maximally elongated antheroconid remains unoccupied. The distribution of morphotypes for the complex of species in the space of the first two axes of multidimensional scaling forms a single and almost homogeneous cloud that almost evenly fills the total morphospace. The correlation coefficients between the matrices of morphogenetic and Procrustean distances between morphotypes calculated for each of the species vary from 0.56 to 0.73.