Neogene tectonics and climate forcing of carnivora dispersals between Asia and North America.

Exchange records of terrestrial mammals can be combined with available tectonic and climatic documents to evaluate major biological and environmental events. Previous studies identified four carnivoran dispersals between Eurasia and North America in the Neogene, namely, at ~ 20, 13-11, 8-7, and ~ 4Ma. In order to evaluate driving mechanism of these biological events, we collected, compared and analyzed a large number of published records. The results indicate that the carnivoran dispersal from Eurasia to North America at ~ 20Ma was probably caused by intense tectonic movements in Asia. During 13-11 Ma, global cooling possibly drove the mammal exchanges between Eurasia and North America. By comparison, the carnivoran dispersal from Eurasia to North America at 8-7Ma was probably caused by the combination of global cooling and tectonic movements of the Tibetan Plateau. Similar to during 13-11 Ma, the carnivoran exchanges between Eurasia and North America at ~ 4Ma were possibly driven by global cooling. [ABSTRACT FROM AUTHOR]