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.
Literature Cited
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."