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: (i) characterize tempo and patterns of diversification; (ii)
assess the impact of the EOEE; and (iii) 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, the diversification rate declined or did
not shift following geographical 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 land masses
of Earth.