Geomorphometric differences among four species of <i>Microtus</i> in Turkey (Mammalia: Rodentia)

<p>In order to determine the phenotypic associations of four morphologically similar species of <i>Microtus</i> occurring in Turkey, we applied landmark-based shape analysis. The skulls of <i>Microtus anatolicus</i>, <i>M. dogramacii</i>, <i>M. guentheri</i> and <i>M. levis</i> (= <i>M. rossiaemeridionalis</i>) were found to differ significantly in terms of both size and shape. <i>M. guentheri</i> had the biggest skull, while <i>M. levis</i> had the smallest. Sexual dimorphism was found in the shape of the skull in <i>M. dogramacii</i> and <i>M. levis</i>. The tympanic bulla area is enlarged in <i>M. anatolicus</i> compared to the other species. Mahalanobis distances (the distance between a point and the group mean, taking into account the within-group covariance-variance matrix) confirm the distinction of the <i>arvalis</i> group (<i>M. levis</i>) and <i>socialis</i> group (<i>Microtus anatolicus</i>, <i>M. dogramacii</i>, <i>M. guentheri</i>).