Monophyly of the Tyrannidae (Aves): Comparison of Morphology and DNA

The hypothesis of monophyly of the avian family Tyrannidae is tested using outgroup comparison of traditional characters, as well as several characters examined in recent studies of the group. No characters support the original hypothesis, but possession of internal cartilages in the syrinx and an intrinsic syringeal muscle, M. obliquus ventralis, supports monophyly of a slightly larger group. A published phylogeny based on DNA-DNA hybridization data suggests a different view: that the Tyrannidae is not monophyletic; and that some traditional tyrannids are more closely related to members of the Cotingidae and Pipridae than to the rest of the family as currently recognized. The significance of the different results of these approaches is discussed.