On the possibility of identifying pikas, Ochotona (Lagomorpha: Ochotonidae), on the basis of the morphology of the occlusal surface of permanent teeth

Abstract

Variation in the morphology of the occlusal surface of the third lower premolar tooth was examined in 69 skulls from adult specimens of four pika species. Variation was examined using standard geometric morphometric techniques as well as analysis of distances between landmarks (with and without accounting for the size factor). The results were checked on a sample of 46 specimens, specifically by comparing inter-species variance in dental and cranial features. Interspecies variation was low in the case of shape-only analysis of features of the third lower premolar, independent of the method used. Adding the size factor to the analysis notably increased the interspecies variation in teeth. Analysis of cranial data displayed more prominent interspecies variation compared to dental data, both with and without information on skull size. Sexual variation was minimal in all analyses. Thus, we suggest using information on tooth size for the purpose of species identification on the basis of the morphology of the occlusal surface of permanent teeth in pikas. In this case, morphological study of the occlusal surface of teeth could contribute to Ochotona species identification.