Late Miocene Asian monsoon intensification and turnover of Asian mammal communities

The late Miocene was a critical period in Earth’s climate and biosphere evolution, with intensified climate variability, major terrestrial ecosystem reorganization, and formation of modern-like Tibetan Plateau. However, mechanisms linking these transformations remain elusive. Here we integrate quantitative Asian summer monsoon precipitation and qualitative Asian winter monsoon intensity reconstructions, mammalian fossil records, and climate simulations to investigate this nexus in the mammal-rich northeastern Tibetan Plateau. Results show near-synchronous Asian summer and winter monsoon intensification and pronounced biotic turnover at ~8.7 Ma. We attribute these to late Miocene global cooling and northern Tibetan Plateau uplift, which together enhanced Asian monsoon circulation. Climate modelling under different palaeotopographic scenarios highlight the critical role of northern Tibetan Plateau uplift in strengthening monsoon dynamics. These findings emphasize the late Miocene as a key interval of coupled climatic, tectonic, and ecological transitions, and the importance of Tibetan Plateau uplift in modulating regional climate and biodiversity evolution. Northern Tibetan Plateau uplift and global cooling drove synchronous monsoon intensification and turnover of Asian mammal communities at ~8.7 Ma, according to Asian monsoon reconstructions and mammalian fossil records plus model simulations.