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

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.

KEYWORDS:

• Inner Mongolia
• Eocene
• tapiroids
• paleodiet
• palaeoecology
• microwear

Acknowledgments

We thank Wei Zhou, Shijie Li, Qi Li, Yongxing Wang, Yongfu Wang, Liqun Shi, Xijun Ni, Tianyu Wang, K Christopher Beard, Daniel L. Gebo, Chengkai Sun, Jian Wang, Qiang Cao, Qiang Li and Wei Gao for the field work; Shijie Li (IVPP) for preparation of specimen; Sukuan Hou, Qinqin Shi and Shiqi Wang (all from IVPP) for laboratory assistance and academic discussion. We also thank the editor Dr Gareth Dyke, and Alline Rotti and two anonymous reviewers for their careful reading of our manuscript and their insightful comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Strategic Priority Research Program of Chinese Academy of Sciences [XDB26000000]; the National Natural Science Foundation of China [41572021, 41672014]; and the ‘Joint PhD Training Program’ in University of Chinese Academy of Sciences.