Monophyly and Phylogeny of the Schiffornis Group (tyrannoidea)’

A cladistic analysis of 19 characters was used to investigate the phylogeny of the Schzjornis group, a monophyletic assemblage of six genera of suboscine passerines which are currently placed in three different tyrannoid families: Schzfirnis (Pipridae, manakins), Laniisoma, Zodopleura (Cotingidae, cotingas), Laniocera, Xenopsaris, and Pachyramphus (Tyrannidae, tyrant flycatchers). The character systems analyzed include syringeal and cranial morphology, plumage, and nest architecture. Monophyly of the Schijornis group was supported by two syringeal synapomorphies. Within the group, the phylogenetic relationships of five of the six genera were resolved; Schzfirnis is the sister group to Laniisoma and Laniocera, and Xenopsaris is the sister group of Pachyramphus. The relationship of Zodopleura to these two corroborated clades was not resolved. The higher-level relationships of the Schzjornis group to other tyrannoids was not resolved. Results of two previous biochemical phylogenies of tyrannoids both corroborate and conflict with this morphological hypothesis. Comparative analysis of the evolution of breeding systems in tyrannoids indicates that polygyny may have developed independently within the group, resulting in the evolution of a novel form a male advertisement behavior without conspicuous sexual dimorphism and a distinct type of spatial dispersion of male territories.