Proposal(313) toSouth AmericanClassification Committee
Literature Review:
Traditionally,Iodopleura, Laniisoma, Tityra, and Pachyramphus werein the Cotingidae,Schiffornis was in the Pipridae, andLaniocera wasin the Tyrannidae. Ames (1971) first suggested thatTityraand Pachyramphusbe removed from the Cotingidae on the basis of syringeal morphology andplaced in the Tyrannidae. Although they were subsequently often associated withone another, Ames actually presented no data indicating any relationshipbetween the two other than as former cotingids transferred to the Tyrannidae.
Allozyme analysis by Lanyon (1985) supported a close relationshipbetweenTityraandPachyramphus, but with a rather smallsampling of other tyrannoids.
Prum and Lanyon (1989) first proposed a tyrannoid suboscine cladeincluding the generaSchiffornis, Laniisoma, Laniocera, Pachyramphus,Xenopsaris,andIodopleura based on a phylogenetic analysis ofsyringeal and skeletal morphology. They called this clade theSchiffornisgroup. Prum and Lanyon specifically examinedTityra and found noshared derived morphological characters uniting it to the rest of theSchiffornis groupgenera.
Subsequent molecular analyses using a variety of mitochondrial andnuclear DNA sequences supported the existence of a clade including someSchiffornisgroup members with the addition ofTityra(Chesser 2004; Ericson etal. 2006; Johansson et al. 2002; Prum et al. 2000), but none of these analysesincluded members of each genus.
Most recently, Ohlson et al. (2007) published the first molecularphylogenetic hypothesis that included all five of sixSchiffornisgroupgenera (missingXenopsaris) andTityra, and a broad sample ofother cotingids. The results confirmed the monophyly of an expandedSchiffornisgroup to includingTityra. The molecular phylogeny was exactlycongruent with the hypothesis of Prum and Lanyon withTityraincludingas the sister toPachyramphus.Molecular data fromXenopsaris arestill lacking, but it shares numerous derived syringeal features withPachyramphus(Prum and Lanyon 1989). The molecular data largely confirm themorphological cladistic characters, with the exception ofTityrahavingevolved a very divergent (and simplified) syringeal structure since commonancestry withPachyramphus.
Prum and Lanyon (1989) were unable to resolve the higher-levelrelationships of theSchiffornisgroup. Prum et al. (2000) placed it asa basal clade of the Cotingidae, but this was based on a very small sample ofother tyrannoids. Chesser (2004) placed the clade as the sister to Pipridae,and Johansson et al. (2002) laced them as unresolved in the Tyrannoidea. Ericsonet al. (2006) placed them as sister to Tyrannidae, and Ohlson et al. (2007) hadthem unresolved within Tyrannoidea. Data are still equivocal on therelationship of this clade to other large tyrannoid clades.
Taxonomic Recommendations
Based on these still incomplete molecular data, Prum et al. (2000)proposed placing theSchiffornisgroup genera plusTityra in thesubfamily Tityrinae within the Cotingidae. Johansson et al. (2002) and Chesser(2004) did not make any recommendations. Ericson et al. (2006) recommended thattheSchiffornisgroup genera plusTityrabe placed in the familyTityridae within the Tyrannoidea, along with Tyrannidae, Pipridae, andCotingidae. Relationship among these families is still unresolved, and nearlyevery possible combination has been suggested by one data set or another (or inthe case of Sibley and Ahlquist, two possibilities with the same data set). Norecommendation can be made about a phylogenetic ordering for the tyrannoidfamilies.
In addition, Ericson et al. (2006) and Ohlson et al. (2007) placedthe genusOxyruncusas the sister group to theSchiffornisgroupgenera plusTityra. As a result,they both recommended thatOxyruncusalso be included in the Tityridae.There is some syringeal anatomy support for this hypothesis, but thishypothesis is sufficiently novel, thatOxyruncusshould remainIncertaeSedis within Tyrannoidea until some resolution is confirmed by other datasets.
Proposal
Based on the congruent of morphological and molecular data sets,the generaTityra, Pachyramphus, Xenopsaris, Iodopleura, Schiffornis,Laniisoma,andLaniocerashould be placed in the Family Tityridae G.R. Gray 1832-33 within the Tyrannoidea.
This action should leave onlyOxyruncus andPipritesasIncertae Sediswithin the tyrannoids.
References:
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 equivalenttaxonomic rank to Tyrannidae and Cotingidae."
Comments from Stiles: "YES. This group hasprogressively become better substantiated in successive studies as amonophyletic assemblage of family rank. We have already recognized Oxyruncidae(which as a monotypic family is in a sense equivalent to incertae sedis), andsince it has been so treated in many publications over the years, I suggestleaving it as such - at least for now. This would leavePiprites as theonly true "incertae sedis" and until its relationships aredetermined, it should stay this way."
Comments from Stotz: "YES. It has seemedprogressively clearer that we were headed toward this and the new moleculardata pretty well clinches this change."
Comments from Robbins: "YES. As pointed out byothers, the latest molecular data set unequivocally establishes monophyly inthis group. I agree with Gary, that we continue to recognizeOxyruncus atthe family level, leavingPiprites as the sole "incertaesedis" taxon."
Comments from Nores: "YES.Los datos moleculares muestran claramente que Tityra, Pachyramphus,Xenopsaris, Iodopleura, Schiffornis, LaniisomayLaniocera conformanun grupo monofilético. Aunque en la propuesta de Prum no está muy claro porquetienen que conformar una familia aparte y no una subfamilia de Cotingidae, enEricson et al. (2006) y Ohlson et al. (2007) resulta bien evidente
Additional comments from Remsen: "The most recent Aukhas a paper by Barber and Rice that further establishes the monophyly of thisgroup and advocates family rank."
Comments from Zimmer: "YES. Monophyly appearscertain, and rank at the family level seems appropriate. Gary's suggestion ofretainingOxyruncusas a monotypic family and leavingPiprites asincertae sedis seems most reasonable."
Comments from Jaramillo: "YES - Great to delete a fewmore incertae sedis, seems like progress. Data are clear that the familyTityridae is a good choice."