The structure of morphological variation in the shape of occlusal surface of permanent teeth in pikas Ochotona (Lagomorpha: Ochotonidae)

Abstract

Variation in the shape of the occlusal surface of permanent teeth was examined in 102 skulls of four species of pikas. Variance components analysis was carried out on Procrustean coordinates retrieved from 71 and 65 landmarks positioned on the lower and upper teeth rows respectively. The main variance was related to the within-group variation, which indicates general instability in the shape of the enamel loops. Sexual variation explained the smallest amount of variance among all factors examined. The highest percentage of age-related variation was found in the premolars of both teeth rows, especially in p3 and P3. The amount of variance due to interspecies variation was relatively low in all analyses, even in the anterior part of p3, which is regularly recommended for the identification of pikas species. There was no evidence of a phylogenetic signal either. Thus we suggest more careful investigation of the role of features of the shape of teeth occlusal surface for species identification. How to cite this article: Volkova V.R., Lissovsky A.A. 2018. The structure of morphological variation in the shape of occlusal surface of permanent teeth in pikas Ochotona (Lagomorpha: Ochotonidae) // Russian J. Theriol. Vol.17. No.2. P.91–99. doi: 10.15298/rusjtheriol.17.2.05