AbstractAfrican rodents of the genusArvicanthisare presently restricted to sub-Saharan savannas and to the Nile Valley. In contrast, their distribution during the Quaternary included most of northern Africa, leading to the emergence of local fossil species. To date, there have been no comprehensive studies ofArvicanthispopulations in northern Africa, neither to clarify their taxonomy nor their paleoecology. The present study aims to explore both morphology and diet of modern and fossilArvicanthisspecies using geometric morphometric and dental microwear analyses on first upper molars. The geometric morphometric analysis efficiently discriminates the studied extant and fossilArvicanthisspecies and allowed for the identification of probable geographical variations within theA.niloticusgroup. Although all extant species of the genusArvicanthisare predominantly grass-eaters, microwear analyses also highlighted diet differences in various modern populations ofA.niloticus, as well as paleodiet inferences in theA.arambourgifossil species, but no clear link between molar size or shape and diet can be established. This work helps set the stage for a complete revision of the fossil remains ofArvicanthisfrom northern African Quaternary deposits, and for a better understanding of the geographical and temporal morphological variability of this genus in Africa.
Read full abstract