Dietary reconstruction and palaeoecology of Eocene Lophialetidae (Mammalia: Tapiroidea) from the Erlian Basin of China: evidence from dental microwear

Abstract

ABSTRACT Schlosseria magister, Breviodon? minutus and Lophialetes expeditus are dominant species in the family of Lophialetidae, an extinct group of tapiroids widely distributed in the Eocene sediments of Asia. In this study, we provide insight into the paleodiet and palaeoecology of these Eocene lophialetids via microwear analysis of fossil teeth (N = 132) from Huheboerhe area, Erlian Basin, China. The results suggest that L. expeditus was likely a mixed feeder consuming substantial grit and a small amount of fruit during feeding, while Breviodon? minutus was a browser with fruit and/or seeds incorporated into its dietary regime. The dietary preference of S. magister shifted towards more abrasive diets over time (from browsers to mixed feeders). This dietary shift is probably correlated to the decreasing trend in global temperatures following the Early Eocene Climatic Optimum which likely led to the changes of terrestrial vegetation and environment in the Huheboerhe area during that time interval. Combining the microwear analysis and other evidence (mesowear, stable carbon isotope and the fossil record), the landscape of the early-middle Eocene Erlian Basin was probably becoming more arid and/or open over time and a mixed habitat, which included forest, woodland and shrubland, was most likely present in the middle. Eocene Erlian Basin.