Dietary preferences and autecology of a basal Holarctic ground squirrel Spermophilinus (Rodentia: Sciuridae: Xerinae), inferred from dental microwear analysis

Abstract

ABSTRACT Spermophilinus is a primitive marmotine ground squirrel from the early Miocene – early Pliocene of Eurasia. Despite the high abundance in small mammal communities, apparently indicating its important role in Neogene terrestrial ecosystems, an autecological study of this taxon based on direct methods has not yet been carried out. Herein, we report on a dental microwear analysis of S. bredai, the type species of the genus, based on the m3 specimens from the early late Miocene locality Grytsiv in western Ukraine. The results suggest that the diet of this ground squirrel has presumably consisted of hard fruit and seeds with no evidence of significant grass consumption or burrowing behaviour, thus suggesting feeding preferences most closely resembling those of the living tree squirrels of the genera Sciurus and Callosciurus. We also discuss the dental microwear of the extant ground and tree-dwelling Sciuridae in relation to their diet.