Systematics and Diversification of the Pantropical Avian Order Coraciiformes

How and why species diversify is a central theme of evolutionary biology. Species-rich, morphologically diverse, pantropical clades provide rare opportunities to explore questions about drivers of diversification in the tropics. Here, we present the first complete species tree of Coraciiformes (six families, ~177 species of kingfishers, motmots, bee-eaters, and allies) produced with 4,858 ultraconserved elements. We used concatenated and species-tree frameworks to analyze our data and we recovered a well-supported tree, which supports two clades within Coraciiformes: 1) bee-eaters sister to rollers + ground-rollers and 2) todies sister to motmots + kingfishers. Our Bayesian, fossil-calibrated tree inferred older divergence dates than higher-level studies have reported for the order. We inferred a Nearctic ancestral range of Coraciiformes that originated approximately 57.4 Ma and Indomalayan origin of kingfishers at 37.5 Ma. With this time-tree and several fossil taxa, we estimated the biogeographic history of the group and inferred Nearctic ancestral ranges for the major divergences in the order. We noted independent dispersals of the Coracii (Coraciidae + Brachypteracidae) into the Afrotropics, bee-eaters into the Paleotropics, and kingfishers into the Australasian tropics.