Proposal (133) to South American Classification Committee
Remove "Schiffornis group" from Cotingidae
Effect on SACC: This would remove the genera Tityra, Schiffornis, Laniocera, Iodopleura, Laniisoma, Xenopsaris, and Pachyramphus from the Cotingidae.
Background: The above genera have been shuffled between Tyrannidae and Cotingidae for much of this century. See Prum & Lanyon (1989) and Prum (1990) for a review. Prum & Lanyon's (1989) and Prum's (1990) analyses of morphological data were sufficient to convince some (e.g. AOU 1998) to place them as Incertae Sedis until their relationships were resolved. Then, Prum et al.'s (2000) analysis of mtDNA sequence data placed them within a broadly defined Cotingidae, and that's why and where they reside in our current sequence.
New data: Johansson et al.'s (2002) analysis of mitochondrial and nuclear DNA sequences (but with perhaps the all-time extreme in limited taxon-sampling) found little or no support for a sister relationship between the Schiffornis group (represented by Schiffornis, Pachyramphus, and Tityra) and core cotingas (represented by Pyroderus).
Chesser (2004) used DNA sequence data (mt and nuclear) from a broader range of taxa and found that the Schiffornis group (represented by the same 3 genera above plus Laniocera and Iodopleura) was not the sister group to core cotingas (represented by Rupicola and Procnias) nor to the Tyrannidae (the traditional alternative), but rather to the Pipridae (bootstrap support 84% with maximum likelihood).
In both cases, support was strong for monophyly (albeit with limited taxon-sampling) of the Schiffornis group.
Analysis: The basis for inclusion of the Schiffornis bunch in the Cotingidae is Prum et al. (2000). I think that Rick would be the first to point out that Prum et al.'s (2000) analysis would not be publishable now because only 375 bp of sequence were analyzed (vs. 1000++ for such analyses "nowadays"). Furthermore, they analyzed only cytochrome b, whose utility at higher-level systematics may be limited, and did not report bootstrap values. Although they concluded that the Schiffornis group should be included as a subfamily of the Cotingidae, the node supporting this (vs. relationship to Pipridae or Piprites) has essentially no support in their analysis, and no Tyrannidae were included in the analysis.
Given the two more recent studies above and given that Rick's previous morphological studies did not find strong support for inclusion of these genera in the Cotingidae, my conclusion is that we essentially have no data to support the current classification and plenty of contrary data.
Recommendation: I vote YES on this because the combination of recent genetic and morphological evidence reduces our evidence for their inclusion in Cotingidae to near zero.
If the proposal passes, then we have to decide WHERE to place these genera. I'll do a separate proposal for that. The only two options that I see are to place them in our suboscine Incertae Sedis (as in AOU 1998 and currently occupied only by Piprites in SACC) or to create a family-level taxon for them (Tityridae).
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.
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.
PRUM, R.O., N. H. RICE, J. A. MOBLEY JA, AND W, W. DIMMICK. 2000. A preliminary phylogenetic hypothesis for the cotingas (Cotingidae) based on mitochondrial DNA. Auk 117: 236-241.
Van Remsen, September 2004
Comments from Stiles: "YES. I agree that the best current evidence indicates that these birds are neither cotingids nor tyrannids. I would not be unhappy with Tityridae (presumably Piprites would also fall here? In its singing behavior it reminds me somewhat of Laniocera)."
Comments from Robbins: "YES; Chesser's molecular data are convincing."
Comments from Nores: "YES, aunque esta propuesta me resulta un poco extra–a debido a que nunca observe que el gˇnero Schiffornis estuviera en Cotingidae o Tyrannidae. Yo siempre lo vi ubicado en Pipridae. De todos modos, si considero que Schiffornis group debe ser removido de Cotingidae. Los datos modernos de Johansson (2000) y Chesser (2004), parecen tener mucho m‡s fundamento que aquellos de Prum y Lanyon."
Comments from Silva: "Yes. I think that a family-level new group (Tityridae) should be the best option given the uncertainties associated with this problem."
Comments from Zimmer: "I vote "YES". No real evidence for maintaining these within Cotingidae. I also think that given the evidence for monophyly within the Schiffornis group (even if all genera weren't included in the analysis), the best thing to do is to create a new family-level grouping (Tityridae), possibly to include Piprites."
Comments from Stotz: "YES. The basis for placing the Schiffornis group within Cotingidae was always very weak, so weak that the Northern AOU never followed Prum 2000 treatment. The mitochondrial DNA sample was too limited, and it has become clear that Cytochrome B is not very useful at this taxonomic level. My personal feeling is that the current data really suggests that a new family, Tityridae, is the way to go."
Comments from Pacheco: "[YES] Ap—s analisar as informa¨›es dispon’veis, o CBRO (o que coordeno) tambˇm acatou estar emo¨‹o e, adicionalmente, decidiu adotar a fam’lia Tityridae Gray para acomodar melhor a presente situa¨‹o."