Global cooling has been proposed as a driver of the Great Ordovician Biodiversification Event (GOBE), the largest radiation of Phanerozoic marine animal life. This study couples a global climate model (FOAM) with a macroecological model (METAL) to reconstruct global biodiversity patterns during the Ordovician. Simulations show that an inverted latitudinal biodiversity gradient characterized the late Cambrian and Early Ordovician under warmer conditions. Mid-Late Ordovician climate cooling led to the development of a modern latitudinal biodiversity gradient and a significant increase in global biodiversity. This increase is attributed to the ecophysiological limitations of marine life and is robust to uncertainties in temperature reconstructions and organism physiology. The findings suggest that the GOBE was primarily driven by global cooling.

Daniel Eliahou Ontiveros, Gregory Beaugrand, Bertrand Lefebvre, Chloe Markussen Marcilly, Thomas Servais, Alexandre Pohl