Data from: Did True Frogs “dispersify”?

The interplay between range expansion and concomitant diversification is of fundamental interest to evolutionary biologists, particularly when linked to intercontinental dispersal and/or large scale extinctions. The evolutionary history of True Frogs has been characterized by circumglobal range expansion. As a lineage that survived the Eocene-Oligocene extinction event (EOEE), the group provides an ideal system to test the prediction that range expansion triggers increased net-diversification. We constructed the most densely sampled, time-calibrated phylogeny to date in order to: (1) characterize tempo and patterns of diversification; (2) assess the impact of the EOEE; and (3) test the hypothesis that range expansion was followed by increased net-diversification. We show that late Eocene colonization of novel biogeographic regions was not affected by the EOEE and surprisingly, global expansion was not followed by increased net-diversification. On the contrary, diversification rate declined or did not shift following geographic expansion. Thus, the diversification history of True Frogs contradicts the prevailing expectation that amphibian net-diversification accelerated towards the present or increased following range expansion. Rather, our results demonstrate that despite their dynamic biogeographic history, True Frogs diversified at a relatively constantly rate, even as they colonized the major landmasses of Earth.