Long-fuse evolution of carnivoran skeletal phenomes through the Cenozoic

Abstract

Ecological opportunities arising from climatic change are hypothesized to promote phenotypic diversification. While neontological analyses are often used to test this hypothesis, extant data only capture time-averaged signals of surviving lineages. More nuanced tests require paired and longitudinal climatic and organismal data. Here, we developed the most comprehensive phenomic dataset to date of pan-carnivorans to test hypotheses that Cenozoic climatic change influenced the evolution of the cranial, appendicular and axial skeleton. We found support for the hypothesis that a hierarchical progression of ecological diversification across the Cenozoic significantly influenced the establishment of modern carnivorans. Specifically, extinctions during the Eocene–Oligocene Transition released crown carnivorans from a constrained adaptive zone to interfamilial skeletal diversification. Intrafamilial skeletal diversification did not occur for another 20 million years until after the Mid-Miocene Climate Transition. Our work demonstrates the essential role of macroevolutionary data from the fossil record for revealing how major global climatic events steered the evolutionary trajectories of modern skeletal phenomes.