NO CORRELATION BETWEEN CLIMATE AND EXTINCTION IN THE CENOZOIC FOSSIL RECORD OF MAMMALS

There has been a long and acrimonious debate about the role of climate in mammalian extinctions. This exchange has been particularly contentious in regards to the terminal Pleistocene megafauna extinction, which resulted in the loss of all mammals over 600 kg in the New World, including mammoth, mastodon, camels and horses. This event coincided with rapid climate shifts and ecosystem reorganization in the Americas, but it was asynchronous with climate change in Australia and fewer extinctions occurred in the Old World. Thus, whether climate had a role in driving terminal Pleistocene mammal turnover remains unclear. Climate change is not novel in the Earth system; several large-scale swings in temperature and aridity occurred across Cenozoic time. Here, we employ an expanded perspective: using the mammal fossil record and paleotemperature proxies, we examine the influence of the global climate state, climate variability and climate changeon mammalian turnover and extinction selectivity over the entire Cenozoic. We find no evidence of higher (or lower) extinction rates with climate shifts, nor do we find any evidence that larger (or smaller) bodied sized mammals were differentially affected. Our results argue that climate change in the past was not a key driver of extinction in mammals. While climate shifts probably led to changes in abundance, distribution, and morphological adaptation, most mammals were able to cope with the changing environments of the Cenozoic through these mechanisms.