Mandible shape differentiation between Mammuthus trogontherii and M. primigenius and mandible shape ontogeny in M. primigenius specimens from Serbia: A preliminary explorative geometric morphometric study

In this paper, explorative analyses of mandible shape differentiation between two successive species of mammoths (Mammuthus primigenius and Mammuthus trogontherii) and mandible shape ontogeny within Mammuthus primigenius are presented. Although the sample studied is relatively small (only 15 individuals), analysis of interspecific shape differences yielded statistically significant results, while analysis of shape ontogeny did not have statistical support. The visualisation of shape differences showed that the older species, M. trogontherii, had a proportionally wider and dorsoventrally flatter mandible with wider occlusal surfaces, while the latter species had a narrower and taller mandible with narrower, more elongated occlusal surfaces. These morphological differences could be related to a dietary shift as the vegetation changed from steppe and forest-steppe in the middle Pleistocene to the more xeromorph vegetation of steppe-tundra and tundra-steppe of the late Pleistocene. Our analysis shows that even small sample sizes have statistically well supported differences in mandibular morphology in successive species of Mammuthus.