Pliocene bone-cracking Hyaeninae (Carnivora, Mammalia) from the Zanda Basin, Tibet Autonomous Region, China

Abstract

The Zanda Basin in the western Tibet Autonomous Region, China, produces fossils of Miocene–Pleistocene age. Proximity of the basin to the Himalaya Range makes Zanda an important region for understanding vertebrate evolution and dispersal in and around the Tibetan Plateau. Five field seasons of prospecting in the basin have resulted in a rich collection of fossil mammals, with highest abundance and taxonomic richness in the Pliocene section of the Zanda Formation. In this report, we describe the first Tibetan Plateau record of the bone-cracking hyaenine carnivoran Pliocrocuta perrieri from early Pliocene (4.1 Ma) deposits in Zanda. The Zanda Pliocrocuta specimen is the smallest known Pliocrocuta in China. In both morphology and size, it is similar to other early occurrences of Pliocrocuta in Spain and northern China. Materials from Zanda and Yushe represent the earliest and least robust Asian specimens of a highly variable Pliocene hyaenid species, and indicate that Pliocrocuta were already widespread across diverse environments at their first appearance. The presence of two fossil hyaenid species along with at least three canids and one felid in the Plio-Pleistocene Zanda fauna indicates a less deteriorated large predator guild in the Himalayan foothills compared to extant ecological communities in western Tibet.