Dietary and palaeoenvironmental inferences in Neolicaphrium recens Frenguelli, 1921 (Litopterna, Proterotheriidae) using carbon and oxygen stable isotopes (Late Pleistocene; Uruguay)
The Proterotheriidae (Early Palaeocene-Late Pleistocene) were small to medium sized cursorial native South American ungulates (Order Litopterna), having had its diversity peak in the Miocene. During the Pleistocene, the proterotheriid diversity decreased to a single species, Neolicaphrium recens Frenguelli (1921), and few specimens are available from a relatively narrow area at medium latitudes of South America. The first study using stable isotopes (δ13C and δ18O) as proxies is provided here, in order to known dietary preferences and testing previous environmental inferences. The analysed specimens belong to outcrops with OSL ages of 40–30 ka (Late Pleistocene, Sopas Formation of northern Uruguay). The δ13C results of both specimens suggest that at this latitude and tempo, N. recens had browser-feeding preferences, mostly a C3 diet of open canopy forest in an environment of semi-open woodland or forested savannahs and that C4 vegetation would have had a small fraction in their diet. δ18O data suggests a diet composed mostly by fruits, follow by floor plants, with few indication of a folivore diet. The specialized forest browsing diet does not significantly vary based on its site of origin, since both specimens remain in the same isotopic range.
