Timing and patterns of diversification in the Neotropical bat genus Pteronotus (Mormoopidae).

We investigate the biogeographic processes related to the origin and current patterns of distribution of the extant species of the genus Pteronotus. This clade of insectivorous bats is widely distributed in the Neotropical Region and has recently gone through a taxonomic update which increased more than twice its diversity. Using six molecular markers of 15 Pteronotus lineages ranging from Mexico to Central Brazil, we reconstruct a time-calibrated tree and infer molecular evolutionary rates for this bat genus. In addition, estimates of range evolution across phylogeny were obtained through statistical model testing among six different biogeographic models. The origin of the genus Pteronotus occurred approximately 16million years ago (Ma), with initial cladogenesis events being evenly distributed across the phylogeny. Divergence between most closely related species is recent, falling in the Pleistocene period less than 2.6Ma. Mainland lineages present congruent patterns of north versus south continent splitting while insular clades differ in their time of arrival in the Caribbean Islands. Temporal and geographic range estimates for early nodes of Pteronotus phylogeny suggest a central role of Neogene tectonic reorganizations of Central America in the group diversification process. Also, South American colonization by Pteronotus occurred early in the genus history. Founder-event speciation was an important mode of lineage splitting in Pteronotus, with two independent dispersal jumps having occurred to the Greater Antilles. Finally, Pleistocenic sea-level variation and climatic oscillations are possibly associated with divergence between sister-species and recent ages of MRCA for Pteronotus species.