古生态研究组知识库

The transgression and regression of the Tethys Sea profoundly influenced the environment and biodiversity patterns of Eurasia, which had implications for global climate dynamics by altering the land-sea distribution and the broader moisture transport scheme. Despite its importance, few comprehensive studies have integrated fossil data and climate modeling to explore the climate evolution in the Tethys Sea region during the Cenozoic. In this paper, we reconstruct 10 climate parameters using macrofossil flora from 363 sites across the Tethys Sea region throughout the Cenozoic, and we compare these reconstructions with simulations from the Hadley Center Coupled Model (HadCM3). Additionally, we propose a new Mediterranean Climate Index (MCI), which combines precipitation and temperature, to analyze the evolution of the Mediterranean climate. Our results indicate that the climate in the Tethys Sea region gradually changed from predominantly tropical and subtropical conditions during the Paleogene to a warm temperate and cold temperate climate in the Neogene-Quaternary. The distribution pattern of the coldest month mean surface air temperature (CMMT) changed from a predominantly zonal pattern in the Paleogene to a topographically influenced distribution in the eastern and central Tethys regions since the Neogene. The precipitation patterns in the Tethys Sea region exhibited significant fluctuations. In the western Tethys region, the summer precipitation experienced increased variability, while the winter precipitation decreased slightly. The central Tethys region became significantly drier due to sea regression and mountain uplift. Both the summer and winter precipitation increased markedly in the eastern Tethys region with the development of the Tibetan Plateau. From the Eocene to the early Oligocene, the Mediterranean climate prevailed in Central Asia and Europe, but its extent contracted sharply during the Miocene, primarily due to the decrease in the summer precipitation. The Oligocene-Early Miocene was a critical period for climate evolution in the Tethys Sea region, which was driven by changes in the land-sea distribution, topographic evolution, and global CO2 concentration. The results of this study provide a crucial reference for exploring the evolution of ecosystems and species diversity in Eurasia driven by climate change since the Cenozoic.