An examination of the dietary habits of Platybelodon grangeri from the Linxia Basin of China: Evidence from dental microwear of molar teeth and tusks

Abstract

The paleodiet of shovel-tusked gomphotheres from the upper middle Miocene Hujialiang Formation of the Linxia Basin (Gansu Province, China) was assessed via molar microwear analysis of dental enamel. Both adults and an ontogenetic series of individuals of Platybelodon grangeri with assigned dental ages estimated via comparison of eruption and wear to that of extant elephants were analyzed. Mandibular tusks were also examined for microscopic scars to test a long-standing hypothesis that P. grangeri used its mandibular tusks to shovel substrate. Results show a consistent browsing signal throughout all of the age classes studied. Evenso, scratch numbers are higher and scratch widths are greater in older individuals indicating that coarser browse was consumed in older versus younger individuals. Results are more similar to those of the extant forest elephant (Loxodonta cyclotis) than to other extant forms (Loxodonta africana and Elephas maximus). Mandibular tusk microwear is very fine and inconsistent with the usage of lower tusks to shovel aquatic or terrestrial substrates and more consistent with stripping vegetation than as shoveling agents.