Data from: Unveiling the diversification dynamics of Australasian predaceous diving beetles in the Cenozoic

During the Miocene, Australia experienced a major climatic and ecological turnover that still escalates today. Flourishing tropical ecosystems from the Oligocene were progressively restricted to the coasts and replaced by more arid-adapted floral and faunal communities. While the role of the Miocenic desertification has been investigated in various diversification events of terrestrial organisms, the response of freshwater clades remains poorly investigated. To gain insights into the diversification processes underlying the mechanisms of a freshwater radiation, we studied the evolutionary history of the Australasian predaceous diving beetles of the tribe Hydroporini (147 described species). We used an integrative approach including the latest methods in phylogenetics, divergence time estimation, ancestral character state reconstruction, and likelihood-based methods of diversification rate estimation. Phylogenies and dating analyses were reconstructed with molecular data from seven genes (mitochondrial and nuclear) for 117 species (plus 12 outgroups). Robust and well-resolved phylogenies indicated a late Oligocene origin of Hydroporini with an important period of diversification in the Miocene. Biogeographic analyses showed an origin in the East Coast of Australia, and a dynamic biogeographic scenario implying dispersal events. The group successfully colonized the tropical coastal regions carved by a rampant desertification, and also colonized groundwater ecosystems in Central Australia. Diversification rate analyses suggest that aridification of Australia has not only triggered an extraordinary radiation of the group resulting in a striking boost of species accumulation explained by constant diversification rate until the early Pliocene, but has also contributed to a major wave of extinctions since the late Pliocene, probably attributable to on-going aridity and range contractions. When comparing subterranean and epigean genera, we also unveiled different diversification processes explaining their current diversity pattern. As a result, this Australasian radiation has been promoted by climatic shifts that likely opened new ecological opportunities, and as continental Australia carried on drying, the aridification that once favored thriving, started to trigger the wane of the tribe.