Molecular support for a sister group relationship between Pici and Galbulae (Piciformes sensu Wetmore 1960)

Woodpeckers, honeyguides, barbets, and toucans form a well-supported clade with approximately 355 species. This clade, commonly referred to as Pici, share with the South American clade Galbulae (puffbirds and jacamars) a zygodactyls foot with a unique arrangement of the deep flexor tendons (Gadow's Type VI) Based on these characters, Pici and Galbulae are often considered sister taxa, and have in traditional classification been placed in the order Piciformes. There are, however, a wealth of other morphological characters that contradicts this association, and indicates that Pici is closer related to the Passeriformes (passerines) than to Galbulae. Galbulae, in turn, is considered more closely related to the rollers and ground-rollers (Coracii). In this study, we evaluate these two hypotheses by using DNA sequence data from exons of the nuclear RAG-I and c-in);c genes, and an intron of the nuclear myoglobin gene, totally including 3400 basepairs of aligned sequences. The results indicate a sister group relationship between Pici and Galbulae, i.e. monophyly of the Piciformes, and this association has high statistical support in terms of bootstrap values and posterior probabilities. This study also supports several associations within the traditional order Coraciiformes, including a sister group relationship between the kingfishers (Alcedinidae) and a clade with todies (Todidae) and motmots (Momotidae), and with the bee-eaters (Meropidae) placed basal relative to these three groups.