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
_____________________________________________________________________________________
Voting chart for SACC proposals 100-218
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."