TY - JOUR T1 - A multiscale view of the Phanerozoic fossil record reveals the three major biotic transitions JF - bioRxiv DO - 10.1101/866186 SP - 866186 AU - Alexis Rojas AU - Joaquin Calatayud AU - Michal Kowalewski AU - Magnus Neuman AU - Martin Rosvall Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/06/19/866186.abstract N2 - The hypothesis of the Great Evolutionary Faunas is a foundational concept of macroevolutionary research postulating that three global mega-assemblages have dominated Phanerozoic oceans following abrupt biotic transitions. Empirical estimates of this large-scale pattern depend on several methodological decisions and are based on approaches unable to capture multiscale dynamics of the underlying Earth-Life System. Combining a multilayer network representation of fossil data with a multilevel clustering that eliminates the subjectivity inherent to distance-based approaches, we demonstrate that Phanerozoic oceans sequentially harbored four global benthic mega-assemblages. Shifts in dominance patterns among these global marine mega-assemblages are abrupt (end-Cambrian 494 Ma; end-Permian 252 Ma) or protracted (mid-Cretaceous 129 Ma), and represent the three major biotic transitions in Earth’s history. This finding suggests that the mid-Cretaceous radiation of the so-called Modern evolutionary Fauna, concurrent with gradual ecological changes associated with the Mesozoic Marine Revolution, triggered a biotic transition comparably to the transition following the largest extinction event in the Phanerozoic. Overall, our study supports the notion that both long-term ecological changes and major geological events have played crucial roles in shaping mega-assemblages that dominated Phanerozoic oceans.Competing Interest StatementThe authors have declared no competing interest. ER -