Proposal (134) to South American Classification Committee
Reinstate family Oxyruncidae
Effect on SACC: This would remove Oxyruncus cristatus from the Cotingidae and elevate it to the rank of a monotypic family, as in AOU (1998).
Background: Until recently, Oxyruncus cristatus was traditionally listed as a monotypic family in the tyrannoid section of the suboscines. DNA-DNA sequence data (Sibley et al. 1984, Sibley & Ahlquist 1995, 1990) and a short sequence of mtDNA (Prum et al. 2000) indicated that Oxyruncus should be included in the Cotingidae. Allozyme data placed it closest to Pachyramphus, Tityra, and Piprites. Syringeal structure has been interpreted as indicating that it belongs in the Tyrannidae (Ames 1971, McKitrick 1985) but see Prum (1990).
New data: Johansson et al. (2002) [see Prop. 133 for brief description of that project] were unable to resolve the relationships of Oxyruncus. In fact, Johansson et al. stated that with respect to Prum et al.'s mtDNA study: "However, that study was flawed by the apparent use of a nuclear copy of cytochrome b." [I don't know the details on this -- Rick?]
Chesser (2004) [see Prop. 133 for brief description of that project] found that Oxyruncus clustered with the Tyrannidae + Tityrinae + Pipridae and not with the Cotingidae.
Analysis: The basis for inclusion of Oxyruncus in the Cotingidae rests on controversial DNA-DNA hybridization data (e.g., see Chesser 2004) and an unacceptably short sequence of mt DNA (373 bp) from Prum et al. (2000). Chesser's data clearly conflict with this, as do those of Johansson to a lesser extent. My conclusion is that there was no solid basis for placement of Oxyruncus in Cotingidae, and that restoration as a monotypic family, the traditional treatment, is warranted. The only other treatment that fits the data is to place it Incertae Sedis in tyrannoid suboscines.
Lapsing into speculation, I can envision this bizarre bird as the sole representative of some ancient and now fizzling group. Its distribution is highly relictual, and its morphology can be interpreted as mosaic: it has the crown patch of a tyrannid or piprid, the plumage pattern of a cotinga (especially Phibalura, but is that a cotinga???), and the bill of a .... of a ... of a .... hmmm, well, no other tyrannoid.
Recommendation: I vote YES on this because the evidence for its inclusion in Cotingidae is insufficient to have changed from the historical classification. Oxyruncus may well be embedded in one of the major tyrannoid families, but evidence for any particular treatment ranges from unacceptable to suggestive. I suggest that the only honest representation of this in a classification is to reinstate the monotypic family until data dictate otherwise.
AMES, P. L. 1971. The morphology of the syrinx in passerine birds. Bulletin Peabody Museum Natural History 37: 1-194.
CHESSER, R. T. 2004. Molecular systematics of New World suboscine birds. Molecular Phylogenetics and Evolution 32: 11-24.
JOHANSSON, U. S., M. IRESTEDT, T. J. PARSONS, AND P. G. P. ERICSON. 2002. Basal phylogeny of the Tyrannoidea based on comparisons of cytochrome b and exons on nuclear c-myc and RAG-1 genes. Auk 119: 984-995.
MCKITRICK, M. C. 1985. Monophyly of the Tyrannidae (Aves): comparison of morphology and DNA. Syst. Zool. 34: 35-45.
PRUM, R.O. 1990. A test of the monophyly of the manakins (Pipridae) and of the cotingas (Cotingidae) based on morphology. Occ. Papers Museum of Zoology, Univ. of Michigan 723: 1-44.
PRUM, R. O., AND W. E. LANYON. 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91: 444-461.
SIBLEY, C. G., AND J. E. AHLQUIST. 1985a. The phylogeny and classification of New world suboscine passerines (Passeriformes: Oligomyodi: Tyrannides). Ornith. Monogr. 36: 396-430.
SIBLEY, C. G., S. M. LANYON, AND J. E. AHLQUIST. 1984. The relationships of the Sharpbill (Oxyruncus cristatus). Condor 86: 48-52.
SIBLEY, C. G., AND J. E. AHLQUIST. 1990. Phylogeny and classification of birds. Yale Univ. Press, New Haven, Connecticut.
Van Remsen, September 2004
Comments from Stiles: "YES. If the evidence for including the sharpbill in Cotingidae comes up short and the tyrannid-tityrid connections are at best equivocal, I vote for separate family status. It IS an oddball - its bill and foraging behavior are unique in the entire tyrannoid radiation and it fits poorly in any of the other described families. A monotypic family describes its isolated position better than "incertae sedis".
Comments from Robbins: "YES; based on Chesser's molecular data it seems best to place this unique bird in its own family."
Comments from Nores: "YES. Yo no veo razón suficientemente comprobada como para eliminar la Familia Oxyruncidae, especialmente después de ver los análisis de Chesser y de Johansson y del que hace Remsen en la propuesta. Además, es tan diferentes en aspecto de una cotinga, que resulta difícil de pensar de que puedan haberlos puestos juntos. De todos modos, esto plantea un problema que yo vengo viendo desde hace bastante tiempo. En muchos casos se aceptan cambios por el solo hecho de que existe algún estudio genético realizado y no necesariamente definitivo. En este caso, si no hubiera aparecido los trabajos de Chesser y de Johansson, más de uno de nosotros habría dicho que existiendo un trabajo sobre hibridisación de DNA de Sibley et al. Y otro basado en DNA mitocondrial de Prum et al. lo más adecuado sería poner Oxyruncus junto con las cotingas. En otras palabras, se le viene dando demasiada importancia a la parte genética."
Comments from Zimmer: "I vote "YES" for reasons already outlined by others."
Comments from Stotz: "YES. I could also support its placement as Incertae Sedis. I think probably it makes sense to go with Incertae Sedis if we do that with "Tityridae," and as a separate family if we go that route for Tityridae."
Comments from Pacheco: "YES. Diante dos resultados de Chesser, é forçoso admitir que o tratamento tradicional de Oxyruncus em família monotípica é o mais apropriado. Este arranjo foi igualmente acatado pelo CBRO."
Comments from Jaramillo: "YES . Reinstating to its own family is appropriate given new data."