Climatic change is hypothesized to promote phenotypic diversification. While neontological analyses are often used to test this hypothesis, extant data only captures the time-averaged signal of surviving lineages. More nuanced tests require paired and longitudinal climatic and organismal data from the fossil record. Here, we developed the most comprehensive phenomic dataset of pan-carnivorans incorporating fossil and extant data (118 extant and 81 extinct species) to test hypotheses that Cenozoic climatic change influenced the tempo and mode of the cranial, appendicular, and axial skeleton. We found equal support for two release and radiate models, where skeletal evolution transitioned from an Ornstein-Uhlenbeck process to Brownian motion at the Eocene-Oligocene Transition (EOT) and the Mid-Miocene Climate Transition (MMCT). Disparity-through-time analyses reveal that the EOT led to decreased subclade disparity whereas the MCCT led to increased disparity. Our results suggest that climate transitions facilitated the diversification of skeletal phenomes under a long-fuse model. Specifically, EOT-induced extinction of coeval stem pan-carnivorans released crown carnivorans from a constrained adaptive zone, resulting in phenotypic diversification among families from the Early Oligocene to Mid-Miocene. Intrafamilial skeletal phenome diversification did not occur for another 20 million years until after the MMCT. Overall, the hierarchical progression of ecological diversification across the Cenozoic significantly influenced the establishment of modern carnivorans. 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.