Portal de Periódicos da CAPES

Higher-Order Phylogenetics of Modern Aves Based On Comparative Anatomy

2001; Brill; Volume: 51; Issue: 2 Linguagem: Inglês

10.1163/156854201x00260

1568-542X

Bradley C. Livezey, Richard L. Zusi,

Morphological variations and asymmetry

New fossils have contributed much to our knowledge of avian origins but have shed little light on higher-order relationships among modern Aves. This is because the primary focus of paleornithology, the discovery and description of new fossil taxa, has not been paralleled by the development of new anatomical characters for phylogenetic reconstructions. Despite an appreciation of morphological characters for phylogenetics, in part a result of paleontological studies, no anatomically based, taxonomically comprehensive, phylogenetic reconstruction of higher-order relationships of birds exists at present. Accordingly, we have undertaken phylogenetic (cladistic) analysis of Mesozoic and modern birds based on the under-utilized wealth of anatomical evidence and drawing primary strength from comparatively complete, neontological specimens. A pilot study - including study of juvenile skeletons (for discernment of suturae), opened crania (for internal characters of the braincase), myological dissections, and a review of the pertinent literature - indicates that at least 1,200 anatomical characters will prove informative for the analysis, a richness exceeding that for any anatomical analysis of tetrapods to date. Here we present an outline of our analytical approach, illustrated by selected examples of challenging anatomical characters, and a preliminary phylogenetic hypothesis based on osteological characters compiled to date. Finally, we advocate the adoption of ICAAN nomenclature, championed by J. Vanden Berge and colleagues, for description of characters and to standardize hypotheses of homology.