The paleoenvironments and ecosystems of northern China during the Miocene are complex topics, especially concerning the impact of the uplift of the Tibetan Plateau on the surrounding areas and the ecological adaptations of mammals. Our analyses using stable carbon and oxygen isotope analysis, cenograms, and hypsodonty of herbivorous mammals reveal open, arid, savanna-like habitats in the Junggar Basin during the middle Miocene, which subsequently spread to northern China by the late Middle Miocene. Large herbivores, particularly proboscideans and rhinocerotids, exhibited strong adaptations to these open environments. However, smaller taxa maintained a preference for more closed, forested areas. Despite global climate events, faunal diets in the Junggar Basin remained consistent, although biodiversity declined, indicating increased ecological pressure. Our findings contribute to understanding middle Miocene paleoecology in northern China and the adaptive strategies of mammals in response to environmental changes.

The paleoenvironments and ecosystem of northern China during the Miocene are complex issues, particularly because it relates to the impact of the uplift of the Tibetan Plateau on the surrounding areas and the ecological adaption of mammals. Our analyses using stable carbon and oxygen isotope analysis, cenograms, and hypsodonty of large herbivorous mammals reveal arid and open habitats in the northern Junggar Basin, and the different adaptations of mammalian taxa. In the early Middle Miocene, the Junggar Basin witnessed the emergence of savanna habitats characterized by an open landscape. This habitat further spread to northern China during the late Middle Miocene, indicating the widespread distribution of savannas in these regions. This shift is linked to the rapid elevation of the Tibetan Plateau's northern part, accelerating Central Asia's aridification. Our findings enhance our understanding of the Middle Miocene paleoecology in northern China and the adaptive strategies of mammals to environmental changes.