Phylogenetic relationships among the Tyrannides were assessed using over 4000 base pairs of nuclear recombination activating 1 (RAG-1) and 2 (RAG-2) DNA sequence data from about 93% of all described genera, which represents the most complete assessment of relationships for this diverse New World radiation to date. With this sampling we propose a significantly expanded interpretation of higher-level relationships within the group. The Tyrannides are shown to be comprised of six major lineages, all of which represent traditional family-level taxa (sensu Fitzpatrick, 2004a and Snow, 2004a,b;del Hoyo et al., 2004): (i) manakins (Pipridae); (ii) cotingas (Cotingidae); (iii) the sharpbill (Oxyruncus) + onychorhynchine flycatchers (Onychorhynchini); (iv) tityrines (Tityridae); (v) rhynchocycline flycatchers (Rhynchocyclidae); and (vi) the tyrant flycatchers (Tyrannidae). In addition, the RAG data recovered isolated lineages with uncertain relationships, including Neopipo, Platyrinchus, Piprites, and Tachuris. The Pipridae are the sister-group to all the other Tyrannides. Within the latter, the clade ((Oxyruncidae + Tityridae) + Cotingidae) is the sister-group of the Tyrannoidea. Within the Tyrannoidea, the Rhynchocyclidae and their allies are sisters to Neopipo + Tyrannidae. Using our phylogenetic hypothesis, we propose the first comprehensive phylogenetic classification that attempts to achieve isometry between the tree and a classification scheme using subordination and phyletic sequencing. This study thus provides a phylogenetic framework for understanding the evolution of this diverse New World assemblage, and identifies many avenues for further systematic study.

The infraorder Furnariides is a diverse group of suboscine passerine birds comprising a substantial component of the Neotropical avifauna. The included species encompass a broad array of morphologies and behaviours, making them appealing for evolutionary studies, but the size of the group (ca. 600 species) has limited well-sampled higher-level phylogenetic studies. Using DNA sequence data from the nuclear RAG-1 and RAG-2 exons, we undertook a phylogenetic analysis of the Furnariides sampling 124 (more than 88%) of the genera. Basal relationships among family-level taxa differed depending on phylogenetic method, but all topologies had little nodal support, mirroring the results from earlier studies in which discerning relationships at the base of the radiation was also difficult. In contrast, branch support for family-rank taxa and for many relationships within those clades was generally high. Our results support the Melanopareidae and Grallariidae as distinct from the Rhinocryptidae and Formicariidae, respectively. Within the Furnariides our data contradict some recent phylogenetic hypotheses and suggest that further study is needed to resolve these discrepancies. Of the few genera represented by multiple species, several were not monophyletic, indicating that additional systematic work remains within furnariine families and must include dense taxon sampling. We use this study as a basis for proposing a new phylogenetic classification for the group and in the process erect new family-group names for clades having high branch support across methods.