Morphological Disparity among Rock Voles of the Genus <i>Alticola</i> from Mongolia, Kazakhstan and Russia (Rodentia, Cricetidae)

The Central Asian high-mountain or rock voles of the genus Alticola Blanford, 1881 are one of the least studied groups of rodents. Taxonomic status of various geographic forms is not yet established until our days. This genus is not enough examined by biochemical and molecular genetic methods. We analyzed morphological disparity among rock voles of the genus Alticola from 8 localities. The samples studied represent 7 nominal species: A. semicanus Allen, 1924 (East Mongolia), Alticola argentatus Severtzov, 1879 (East Kazakhstan), A. tuvinicus Ognev, 1950 (Russia: Tuva), A. olchonensis Litvinov, 1960 (Russia: Olchon Island), A. macrotis Radde, 1861 (Russia: Khamar-Daban ridge), A. lemminus Miller, 1899 (Russia: South Yacutia, Chara Upland) and A. fetisovi Galkina et Yepifantseva, 1988 (Russia: Sokhondo Mnt.). The first three species are attributed to the nominative subgenus Alticola s. str., the last three are included into the subgenus Aschizomys Miller, 1898. As for A. olchonensis both its specific status and subgeneric relationships are disputable. Shape variations of dental crown patterns were examined by means of geometric morphometrics methods. By means of canonical variates analysis (CVA) of partial warps we found distinct divergence between the studied subgenera inferred from the shape of crown patterns of the third upper molar. The voles from Olchon Island differed from all Aschizomys (macrotis, fetisovi, and lemminus), but they were reliably clustered with Alticola s. str. (argentatus, tuvinicus, and semicanus). Our findings supported A. olchonensis to be distinct species within the nominative subgenus Alticola. Morphological disparity (MD) estimated by Procrustes distances was greater in the subgenus Aschizomys than that in the subgenus Alticola.