Proposal
(313) to South American
Classification Committee
Recognize
the Family Tityridae
Literature Review:
Traditionally, Iodopleura, Laniisoma, Tityra, and Pachyramphus were
in the Cotingidae, Schiffornis was in the Pipridae, and Laniocera was
in the Tyrannidae. Ames (1971) first suggested that Tityra and Pachyramphus
be removed from the Cotingidae on the basis of syringeal morphology and
placed in the Tyrannidae. Although they were subsequently often associated with
one another, Ames actually presented no data indicating any relationship
between the two other than as former cotingids transferred to the Tyrannidae.
Allozyme analysis by Lanyon (1985) supported a close relationship
between Tityra and Pachyramphus, but with a rather small
sampling of other tyrannoids.
Prum and Lanyon (1989) first proposed a tyrannoid suboscine clade
including the genera Schiffornis, Laniisoma, Laniocera, Pachyramphus,
Xenopsaris, and Iodopleura based on a phylogenetic analysis of
syringeal and skeletal morphology. They called this clade the Schiffornis
group. Prum and Lanyon specifically examined Tityra and found no
shared derived morphological characters uniting it to the rest of the Schiffornis group
genera.
Subsequent molecular analyses using a variety of mitochondrial and
nuclear DNA sequences supported the existence of a clade including some Schiffornis
group members with the addition of Tityra (Chesser 2004; Ericson et
al. 2006; Johansson et al. 2002; Prum et al. 2000), but none of these analyses
included members of each genus.
Most recently, Ohlson et al. (2007) published the first molecular
phylogenetic hypothesis that included all five of six Schiffornis group
genera (missing Xenopsaris) and Tityra, and a broad sample of
other cotingids. The results confirmed the monophyly of an expanded Schiffornis
group to including Tityra. The molecular phylogeny was exactly
congruent with the hypothesis of Prum and Lanyon with Tityra including
as the sister to Pachyramphus. Molecular data from Xenopsaris are
still lacking, but it shares numerous derived syringeal features with Pachyramphus
(Prum and Lanyon 1989). The molecular data largely confirm the
morphological cladistic characters, with the exception of Tityra having
evolved a very divergent (and simplified) syringeal structure since common
ancestry with Pachyramphus.
Prum and Lanyon (1989) were unable to resolve the higher-level
relationships of the Schiffornis group. Prum et al. (2000) placed it as
a basal clade of the Cotingidae, but this was based on a very small sample of
other tyrannoids. Chesser (2004) placed the clade as the sister to Pipridae,
and Johansson et al. (2002) laced them as unresolved in the Tyrannoidea. Ericson
et al. (2006) placed them as sister to Tyrannidae, and Ohlson et al. (2007) had
them unresolved within Tyrannoidea. Data are still equivocal on the
relationship of this clade to other large tyrannoid clades.
Taxonomic Recommendations
Based on these still incomplete molecular data, Prum et al. (2000)
proposed placing the Schiffornis group genera plus Tityra in the
subfamily Tityrinae within the Cotingidae. Johansson et al. (2002) and Chesser
(2004) did not make any recommendations. Ericson et al. (2006) recommended that
the Schiffornis group genera plus Tityra be placed in the family
Tityridae within the Tyrannoidea, along with Tyrannidae, Pipridae, and
Cotingidae. Relationship among these families is still unresolved, and nearly
every possible combination has been suggested by one data set or another (or in
the case of Sibley and Ahlquist, two possibilities with the same data set). No
recommendation can be made about a phylogenetic ordering for the tyrannoid
families.
In addition, Ericson et al. (2006) and Ohlson et al. (2007) placed
the genus Oxyruncus as the sister group to the Schiffornis group
genera plus Tityra. As a result,
they both recommended that Oxyruncus also be included in the Tityridae.
There is some syringeal anatomy support for this hypothesis, but this
hypothesis is sufficiently novel, that Oxyruncus should remain Incertae
Sedis within Tyrannoidea until some resolution is confirmed by other data
sets.
Proposal
Based on the congruent of morphological and molecular data sets,
the genera Tityra, Pachyramphus, Xenopsaris, Iodopleura, Schiffornis,
Laniisoma, and Laniocera should be placed in the Family Tityridae G.
R. Gray 1832-33 within the Tyrannoidea.
This action should leave only Oxyruncus and Piprites
as Incertae Sedis within the tyrannoids.
References:
Ames, P. L. 1971, The
morphology of the syrinx in passerine birds: Peabody Museum of Natural History
Bulletin, v. 37.
Chesser, R. T. 2004.
Molecular systematics of New World suboscine birds. Molecular Phylogenetics and
Evolution 32:11-24.
Ericson, P. G. P., D.
Zuccon, U. S. Johansson, H. Alvarenga, and R. O. Prum. 2006. Higher-level
phylogeny and morphological evolution of tyrant flycatchers, cotingas,
manakins, and their allies (Aves: Tyrannida). Molecular Phylogenetics and
Evolution 40:471-483.
Johansson, U. S., M.
Irestedt, T. J. Parsons, and P. G. P. Ericson. 2002. Basal phylogeny of the
Tyrannoidea based on comparisons of cytochrome band exons of
nuclear c-myc and RAG-1 genes. Auk 119:984-995.
Lanyon, S. M. 1985.
Molecular perspective on higher-level relationships in the Tyrannoidea (Aves).
Systematic Zoology 34:404-418.
Ohlson, J. I., R. O. Prum,
and P. G. P. Ericson. 2007. A molecular phylogeny of the cotingas (Aves:
Cotingidae). Molecular Phylogenetics and Evolution 42:25-37.
Prum, R. O., and W. E.
Lanyon. 1989. Monophyly and phylogeny of the Schiffornis group
(Tyrannoidea). Condor 91:444-461.
Prum, R. O., N. H. Rice, J.
A. Mobley, and W. W. Dimmick. 2000. A preliminary phylogenetic hypothesis for
the cotingas (Cotingidae) based on mitochondrial DNA. Auk 117:236-241.
Rick Prum,
Sept. 2007
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Comments from Remsen: "YES. The Ohlson et al.
paper, in my opinion, clinches what we have building toward for many years,
namely that this group of genera represents a monophyletic group of equivalent
taxonomic rank to Tyrannidae and Cotingidae."
Comments from Stiles: "YES. This group has
progressively become better substantiated in successive studies as a
monophyletic assemblage of family rank. We have already recognized Oxyruncidae
(which as a monotypic family is in a sense equivalent to incertae sedis), and
since it has been so treated in many publications over the years, I suggest
leaving it as such - at least for now. This would leave Piprites as the
only true "incertae sedis" and until its relationships are
determined, it should stay this way."
Comments from Stotz: "YES. It has seemed
progressively clearer that we were headed toward this and the new molecular
data pretty well clinches this change."
Comments from Robbins: "YES. As pointed out by
others, the latest molecular data set unequivocally establishes monophyly in
this group. I agree with Gary, that we continue to recognize Oxyruncus at
the family level, leaving Piprites as the sole "incertae
sedis" taxon."
Comments from Nores: "YES. Los datos moleculares muestran claramente que Tityra, Pachyramphus,
Xenopsaris, Iodopleura, Schiffornis, Laniisoma y Laniocera conforman
un grupo monofilético. Aunque en la propuesta de Prum no está muy claro porque
tienen que conformar una familia aparte y no una subfamilia de Cotingidae, en
Ericson et al. (2006) y Ohlson et al. (2007) resulta bien evidente."
Additional comments from Remsen: "The most recent Auk
has a paper by Barber and Rice that further establishes the monophyly of this
group and advocates family rank."
Comments from Zimmer: "YES. Monophyly appears
certain, and rank at the family level seems appropriate. Gary's suggestion of
retaining Oxyruncus as a monotypic family and leaving Piprites as
incertae sedis seems most reasonable."
Comments from Jaramillo: "YES - Great to delete a few
more incertae sedis, seems like progress. Data are clear that the family
Tityridae is a good choice."