The Jingxing Hipparion Fauna from the East Piedmont of the Taihang Mountains and Its Biostratigraphic Significance

The Jingxing Hipparion fauna was found in the “Hipparion Red Clay” of the alluvial-fluvial fan on the Tangxian Planation Surface (TPS). This discovery represents the first Hipparion fauna recovered from the east piedmont of the Taihang Mountains and provides direct evidence for regional mammalian evolution and regional stratigraphic correlation. The Jingxing Hipparion fauna is taxonomically diverse, including Alilepus parvus, Felidae gen. et sp. indet., Hyaenidae gen. et sp. indet., Megaviverra sp., Pliohyrax sp., Sivalhippus platyodus, Proboscidipparion pater, Shansirhinus ringstroemi, Propotamochoerus sp., Chleuastochoerus sp., Palaeotragus sp., Schansitherium tafeli, Honanotherium schlosseri, Gazella gaozhuangensis and G. cf. gaudryi. Biochronological observation of this fauna implies an age of latest Miocene to earliest Pliocene (about 6.0-5.2 Ma) or late MN 13, correlated to Taoyang member of Gaozhuang Formation in the Yushe Basin of Shanxi Province. The “Hipparion Red Clay” had not been confirmed from the eastern piedmont of the Taihang Mountains until this discovery. Lithostratigraphic and biostratigraphic correlations indicate that the Neogene strata in this area should be reassigned, and the section yielding the Jingxing Hipparion fauna may represent a new formation. Since the fauna was excavated from TPS, it is concluded that the uplift of this surface occurred no earlier than Early Pliocene. Furthermore, the faunal composition indicates an open forest and grassland environment which is entirely different from that of today.