Proposal (340) to South American Classification Committee

Reassign Dichropogon to Willisornis

The taxon Hypocnemis poecilinota Cabanis, 1847, had been merged in the genus Hylophylax (type species: Conopophaga naevioides Lafresnaye) since Ridgway (1909), a treatment followed by most subsequent authors.

Recently, Brumfield (Proposal 286) proposed to revive the genus Dichropogon Chubb (1918) because molecular data refute monophyly of Hylophylax as currently defined. The ant-following clade that includes H. poecilinotus is not sister to the clade with the other traditional three Hylophylax species (Brumfield et al. 2007).

However, Dichropogon Chubb, 1918, is preoccupied by Dichropogon Bezzi, 1910, a genus for Palearctic asilid flies, considered a junior synonym (Bromley 1951) or a subgenus (Hradsk and Geller-Grimm 1996) of Stichopogon Loew, 1847.

Application of the International Code of Zoological Nomenclature (ICZN 1999) requires the replacement of the junior homonym (Article 60). In lacking an available and potentially valid synonym, Agne and Pacheco (2007) proposed the new generic name Willisornis (after Edwin O'Neill Willis) to replace Dichropogon Chubb, 1918.

References:
Agne, C. E. & J. F. Pacheco (2007) A homonymy in Thamnophilidae: a new name for Dichropogon Chubb. Rev. Bras. Orn. 15(3):484-485.

Bromley, S. W. (1951) Asilid notes (Diptera), with descriptions of thirty-two new species. American Museum Novitates 1532:1-36.

Brumfield, R. T., J. G. Tello, Z. A. Cheviron, M. D. Carling, N. Crochet, and K. V. Rosenberg (2007) Phylogenetic conservatism and antiquity of a tropical specialization: army-ant-following in the typical antbirds (Thamnophilidae). Molecular Phylogenetics and Evolution 45:1-13.

Chubb, C. (1918) Descriptions of new genera and a new subspecies of South American birds. Annals and Magazine of Natural History (Ser. 9) 2:122-124.

Hradsk, M. and F. Geller-Grimm (1996) Eine neue Stichopogon-Art von den Kanarischen Inseln (Diptera: Asilidae). Studia dipterologica 3(2):365-367.

ICZN (1999) International Code of Zoological Nomenclature. Fourth Edition. London: International Commission on Zoological Nomenclature.

Ridgway, R. (1909) New genera, species and subspecies of Formicariidae, Furnariidae, and Dendrocolaptidae. Proceedings of the Biological Society of Washington 22:69-74.

Carlos Eduardo Agne & Jose Fernando Pacheco, March 2008

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Comments solicited by Remsen from Alan P. Peterson: "It appears to me the Dichropogon Chubb 1918, is clearly a junior homonym to the Dipteran genus Dichropogon Bezzi 1910, and is not available as an avian genus group name."

Comments from Nores: "YES. Pienso que la evidencia dada por Brumfield et al (2007) muestra claramente que poecilinota no está relacionada con otras Hylophylax, hecho que también se manifiesta en el color, y por lo tanto necesita otro género. Pero como el género Dichropogon, como proponen ellos, ya está pre-ocupado por un díptero no parece haber dudas de lo que proponen Agne y Pacheco es lo correcto."

Comments from Stiles: "YES. We already passed the proposal to separate Dichropogon, so the taxonomic aspect is not an issue here. In terms of nomenclature, Dichropogon is clearly unavailable, such that a new name is required - and I like Willisornis as a most appropriate name!"

Comments from Stotz: "YES. With Dichropogon unavailable, and Willisornis proposed for poecilinotus, this change is straightforward. There is no reason to reopen the issue of whether poecilinotus belongs in Hylophylax."

Comments from Schulenberg: "YES. I'm not going to go to the trouble of looking up either publication in which the name "Dichropogon" was described (and I bet most of the other people voting on this didn't do so, either, although I hope that at least one person did so). As described in the proposal, the case seems very straightforward. I vote "yes."

Comments from Zimmer: "YES. A name change seems necessary, and given Ed Willis's massive contributions to the literature on antbirds, I can think of no more appropriate name."