The phylogenetic affinities of the Shoebill (Balaeniceps rex)

The phylogenetic affinities between the shoebill (Balaenicipitidae) and pelecaniform and ciconiiform birds are analysed. A cladistic analysis of 54 anatomical characters resulted in monophyly of the taxon (Scopidae + (Balaenicipitidae + Steganopodes (sensu Cracraft 1985))) and showed both Ciconiiformes and Pelecaniformes to be polyphyletic. Derived characters which support the resulting phylogeny are discussed. Monophyly of the taxon (Scopidae, + (Balaenicipitidae + Steganopodes)) is better supported by morphological evidence than monophyly of the taxon (Procellariiformes + (Phaethontidae + Steganopodes)) which was established by Cracraft (1985). The shared derived characters of Scopidae, Balaenicipitidae and Steganopodes are furthermore less easily explained by convergent evolution than by the few characters which support monophyly of the taxon (Phaethontidae + Steganopodes). The Phaethontidae share derived characters with the Procellariiformes, which might support a sister group relationship between the two taxa.