Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary

Frogs are the dominant component of semiaquatic vertebrate faunas. How frogs originated and diversified has long attracted the attention of evolutionary biologists. Here, we recover their evolutionary history by extensive sampling of genes and species and present a hypothesis for frog evolution. In contrast to prior conclusions that the major frog clades were established in the Mesozoic, we find that ∼88% of living frogs originated from three principal lineages that arose at the end of the Mesozoic, coincident with the Cretaceous-Paleogene (K-Pg) mass extinction event that decimated nonavian dinosaurs 66 Mya. The K-Pg extinction events played a pivotal role in shaping the current diversity and geographic distribution of modern frogs.