Molecular phylogenetics of the tody-tyrant and flatbill assemblage of tyrant flycatchers (Tyrannidae)

摘要

The tody-tyrant and flatbill assemblage, sensu Lanyon (1988a), includes 12 genera of tyrant flycatchers known variously as "tody-tyrants" and "flatbills." Lanyon supported the monophyly of the group based on similar skull morphology and nest form, and built intergeneric relationships based on syringeal characters. However, these comparisons were made without a phylogenetic framework. A more recent study assessing relationships in the tyrant flycatchers using published morphological and behavioral data failed to recover monophyly of this assemblage (Birdsley 2002). Using DNA sequence data, we test for the monophyly of the tody-tyrant and flatbill assemblage and compare and contrast phylogenetic signals from mitochondrial and nuclear DNA character systems. We discuss our results in light of results from previous studies. We include representatives of the other major tyrant flycatcher assemblages for a total of 42 individuals (representing 27 tyrannid genera and 36 species). We sequenced 3,022 base pairs (bp) of three mitochondrial genes (ND2, ND3, and cytochrome b) and one nuclear intron (F1135). Our results resolve many of the basal relationships of the tody-tyrant and flatbill phylogeny, but separate and combined analyses of data partitions are necessary to understand the nature of conflict among data sets. The tody-tyrants constitute a monophyletic clade, but the genera Henfitriccus and Lophotriccus are not monophyletic, and the limits of Oncostoina-Lophotriccus need to be revised with more complete sampling at the species level. The flatbills as defined by Lanyon are not monophyletic (Onychorhynchus and Platyrinchus are not true flatbills). Pseudotriccus and Corythopis are sister taxa and, together with Leptopogon and Mionectes, are allied to the tody-tyrant and flatbill clade. Received 7 May 2005, accepted 12 January 2006.