Broadbill

Abstract: Phylogenetic analysis of syringeal morphology and two osteological characters indicates that the broadbills (Eurylaimidae) are not monophyletic, but consist of four clades with successively closer relationships to the Madagascan asities (Philepittidae). An analysis of these data combined with hindlimb myology characters described by Raikow (1987) yields the same result. The sister group to Philepitta and Neodrepanis is the African broadbill Pseu- docalyptomena. The sister group to this clade includes all of the Asian broadbills, except the monophyletic genus Calyptomena. The African genus Smithornis is the sister group to all other broadbills and asities. A biogeographic analysis indicates that the Madagascan endemics share a most-recent biogeographic connection with the central African genus Pseudocalyptomena. Phylogenetic associations between transitions in bill morphology and diet indicate that bill morphologies have evolved both in association with evolution of frugivory and nectarivory, and in apparent response to intrinsic factors within the context of frugivorous and insectiv- orous diets. A phylogenetic classification of the broadbills and asities is proposed in which all broadbills and asities are placed in five subfamilies of the Eurylaimidae, and the separate family Philepittidae is abandoned. Received 27 January 1992, accepted 23 November 1992. THE BROADBILLS (Eurylaimidae), asities (Phi- lepittidae), and pittas (Pittidae) form a clade of Old World suboscine passerines (Sibley et al. 1982, Raikow 1987). They are broadly distrib- uted in tropical Africa, Madagascar, Asia, and the Australo-Papuan region. Although they are much less diverse than the New World subos- cines, the Old World suboscines include an eco- logically diverse group of terrestrial and arbo- real insectivores, frugivores, and nectarivores. As one of the major basal passerine clades, the broadbills, asities, and pittas are an interesting group with which to investigate the biogeo- graphic history of the Old World tropical avi- fauna. In particular, the phylogenetic relation- ships of the asities may provide insight into the biogeographic history of Madagascar. In this paper, I present a phylogenetic analysis of the syringeal morphology of the broadbills (Eury- laimidae) and asities (Philepittidae), and use this phylogenetic hypothesis as a comparative framework in investigations of the biogeo- graphic history and evolutionary ecology of the group. The broadbills include 14 currently recog- nized biological species in eight genera (Peters 1951, Sibley and Monroe 1990). Six genera are restricted to southern Asia (Corydon, Eurylaimus,