Thursday, February 2, 2012



Scissor-tailed Flycatcher (Tyrannus forficatus)
Scientific classification
(but see text)
The suborder of passerine birds Tyranni (the suboscines) includes about 1,000 species, the large majority of which are South American. It is named after the type genus Tyrannus.
These have a different anatomy of the syrinx musculature than the oscines (songbirds of the larger suborder Passeri), hence its common name of sub-oscines. The available morphological,mt and nDNA sequence, and biogeographical data, as well as the (scant) fossil record, agrees that these two major passerine suborders are evolutionarily distinct clades.


According to Sibley and Ahlquist's DNA-DNA hybridization studies the Tyranni can be divided into three suborders: Acanthisittides, Eurylaimides, and Tyrannides. The first, containing theAcanthisittidae (New Zealand "wrens"), is of disputed position. Current opinion is that they are more likely a very distinct and ancient lineage, and constitute a suborder on their own.
The Eurylaimides contain the Old World suboscines - mainly distributed in tropical regions around the Indian Ocean - and a single American species, the Broad-billed Sapayoa:
The former three are usually placed into a distinct superfamily from the pittas, Eurylaimoidea. More recently, as passeriform relationships become better resolved, there is an increasing trend to elevate the Eurylaimides to suborder rank.
The Tyrannides contain all the suboscines from the Americas, except the Broad-billed Sapayoa:
This group has been separated into three parvorders by Sibley & Ahlquist. However, as indicated above, DNA-DNA hybridization has shown to be not very well suited to reliably resolve the suboscine phylogeny. It was eventually determined that there was a simple dichotomy between the antbirds and allies (tracheophones), and the tyrant-flycatchers and allies. Given that the "parvorder" arrangement originally advanced is certainly obsolete (see e.g. Irestedt et al. 2002 for tracheophone phylogeny) - more so if the Eurylaimides are elevated to a distinct suborder - it would be advisable to rank the clades as superfamilies, or if the broadbill group is considered a separate suborder, as infraorders. In the former case, the name Furnarioidea would be available for the tracheophones, whereas "Tyrannoidea", the "bronchophone" equivalent, has not yet been formally defined. In the latter case, the tracheophones would be classified as "Furnariides", while the Tyrannides would be restricted to the tyrant-flycatchers and other "bronchophone" families.
The tracheophones contain the Furnariidae, Thamnophilidae, Formicariidae (probably including most tapaculos), and Conopophagidae. The tyrant-flycatcher clade includes the namesake family, the Tityridae, the Cotingidae, and the Pipridae.

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