Mammalian turnover across the Pliocene-Pleistocene transition: New evidence from the ∼3.0 Ma Dongyancun Fauna, North China

Abstract

The latest Pliocene (∼3.0–2.5 Ma) large mammals were poorly documented in China. Here we report the Dongyancun Fauna from the Sanmenxia Basin, North China, which provides crucial fossil evidence for this interval. We describe new proboscidean and artiodactyl remains, including Stegodon zdanskyi , Mammuthus gromovi , Cervidae gen. et sp. indet., and the first Pliocene record of Leptobos aff. crassus in northern China. The Mammuthus gromovi material includes the first complete hemimandible reported from China, showing relatively derived characters within this pre-Pleistocene mammoth species. Morphological analysis and faunal comparisons place the assemblage firmly within a pre- Equus context, correlating with the late Mazegouan age, supporting a paleomagnetic age of ∼3.0–2.5 Ma. Therefore, the Dongyancun Fauna fills a key temporal gap between the Mazegou and Haiyan faunas. This fauna documents the coexistence of M. gromovi and Leptobos immediately prior to the arrival of true horses and the emergence of Mammuthus meridionalis , highlighting the importance of the Huangdigou section for understanding Pliocene-Pleistocene faunal turnover in East Asia. The Dongyancun Fauna records a key faunal and environmental transition preceding the onset of major Quaternary climatic fluctuations in East Asia, and provides a strong age constraint for the formation of the modern Yellow River.