SRA

Avian diversification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the diversification of Passerines needs closer examination using improved phylogenetic hypotheses and better estimates of the timing of splitting events among passerine lineages. Using 4060 genome-wide loci collected from individuals representing all passerine families, we inferred a phylogenetic hypothesis for passerines using concatenation and coalescent approaches. Across analyses, we recovered a well-supported backbone of passerine relationships and resolved many problematic aspects of passerine phylogeny, although a few relationships remained difficult to disentangle. Our results clarify the position of enigmatic taxa and support the recognition of at least one new avian family. Our time-calibrated phylogeny and biogeographic reconstructions support the hypotheses that: crown passerines originated in the Australo-Pacific during the middle Eocene; the suboscine lineages Eurylaimides, Tyrranida, and Furnariida began diversifying following the Oligocene glaciation; and Old World suboscine passerines are relicts of Laurasian-distributed ancestors that started diversifying during the Late Oligocene Climatic Optimum. Our diversification analyses suggest that passerine speciation increased from the middle Oligocene and peaked during the early Miocene, but we did not find support for an inverse relationship between passerine diversification rate and Cenozoic global temperatures. Although we found support for diversification rate increases in 14 passerine lineages, these shifts did not coincide with a majority of shifts previously estimated for passerines. Our work represents a major step towards a comprehensive understanding of passerine relationships and the influence ecological, geological, and climatological events on the passerine superradiation.