Evolutionary implications of morphological variation in the lower carnassial of red fox<Emphasis Type="Italic">Vulpes vulpes</Emphasis>

Research on the morphological variability of the occlusal surface of M₁ talonid in the red foxVulpes vulpes (Linnaeus, 1758) in the Holarctic has been carried out on 2271 specimens originating from 42 populations. The Nearctic was represented by 666 specimens belonging to 13 populations, whereas Palearctic was represented by 1605 specimens from 29 populations. Analyses of the developmental level and formation of cristids between the hypoconid and entoconid allowed the differentiation of 34 shape variants of the occlusal surface of the talonid in the red fox. Because of the complicated variation of cristids, 34 variants were assigned to 5 morphotypes of group P. In the Palearctic and Nearctic a significant geographic variation occurred of P morphotypes and their variants. Primitive variants of the talonid structure on M₁ are predominant in populations from the south of the Asian range of the red fox, while more progressive characters of the occlusal surface of the lower carnassial are typical of the northern and centrally located red fox populations in the Palearctic and Nearctic. The geographic differentiation is probably connected with different Pleistocene histories of particular populations.