Metaves, Mirandornithes, Strisores and other novelties – a critical review of the higher-level phylogeny of neornithine birds

Recent hypotheses on the higher-level phylogeny of modern birds are reviewed, and areas of agreement and major conflict are detailed, with emphasis being put on congruence among independent molecular and morphological data sets. Although molecular data significantly contributed to a better understanding of avian phylogeny, they do not seem to be free of homoplasy and caution is warranted in the interpretation of some results. The recently proposed Metaves clade is likely to be an artefact of the b-fibrinogen gene, and current molecular data do not yield wellsupported phylogenies for some groups whose interrelationships can be resolved with morphological evidence. There exists, however, congruent and strong molecular evidence for several novel clades that were not recognized by morphologists before, and to ease future discussions the terms Picocoraciae (non-leptosomid Coraciiformes and Piciformes) and Aequornithes ( waterbird assemblage ) are introduced. Molecular studies further congruently recover some clades, which have not yet been adequately appreciated and are outlined in the present review.