Proposal (991) to South American Classification Committee

Recognize the new genus Neophilydor for Philydor erythrocercum and P. fuscipenne (Furnariidae)

Molecular phylogenies have revealed that the traditional genus Philydor turned out to be highly polyphyletic (Derryberry et al. 2011). Some issues have been solved in the past with the transfer of P. ruficaudatum and P. lichtensteini to the genus Anabacerthia, and the transfer of P. erythropterum and P. rufum to the resurrected genus Dendroma. Yet, our current genus Philydor is still not monophyletic because P. erythrocercum and P. fuscipenne are not closely related to Philydor atricapillus, the type species of the genus. The latter is more closely related to the genera Heliobletus and Cichlocolaptes than to the former. This has been shown with datasets of few loci (Derryberry et al. 2011) and new next-generation datasets of UCE data (Harvey et al. 2020), in both cases with high bootstrap support (Bayesian Posterior Probability: 1, Bootstrap support: 100%).

The exact affinities of the clade formed by P. erythrocercum and P. fuscipenne are not fully determined; at least there is a conflict between the Derryberry et al. (2011) tree, which shows them as sister to Megaxenops, and the Harvey et al. (2020) tree, which shows them as sister to Anabazenops. In any case, they are estimated to be very divergent from either (10 and 6 million years respectively), and phenotypically they don’t fit well either: P. erythrocercum and P. fuscipenne have smaller bills, more elongated wings, more squared tails, and shorter tarsi compared to Megaxenops and Anabazenops.

Therefore, the most obvious solution is to separate this clade into its own genus. Given that there are no generic names available for this clade, we described the new genus Neophilydor for this pair of foliage gleaners (Sangster et al. 2023). The new genus is neuter so the specific epithets will remain the same: Neophilydor erythrocercum and Neophilydor fuscipenne.

Recommendation: Without any sensible alternative available, I recommend the adoption of the new generic name Neophilydor for erythrocercum and fuscipenne.

References:

Derryberry, E. P., S. Claramunt, R. T. Chesser, J. V. Remsen Jr., J. Cracraft, A. Aleixo, & R. T. Brumfield. 2011. Lineage diversification and morphological evolution in a large-scale continental radiation: the Neotropical ovenbirds and woodcreepers (Aves: Furnariidae). Evolution 65(10):2973-2986.

Harvey, M. G., G. A. Bravo, S. Claramunt, A. M. Cuervo, G. E. Derryberry, J. Battilana, G. F. Seeholzer, J. Shearer Mckay, B. C. O’meara, B. C. Faircloth, S. V. Edwards, J. Pérez-Emán, R. G. Moyle, F. H. Sheldon, A. Aleixo, B. T. Smith, R. T. Chesser, L. F. Silveira, J. Cracraft, R. T. Brumfield & E. P. Derryberry. 2020. The evolution of a tropical biodiversity hotspot. Science 370(6522):1343-1348

Sangster, G., M. G. Harvey, J. Gaudin, & S. Claramunt 2023. A new genus for Philydor erythrocercum and P. fuscipenne (Aves: Furnariidae). Zootaxa 5361(2): 297–300.

From Sangster et al. 2023:

Santiago Claramunt, January 2024

Comments from Remsen: “YES. I’ve been aware of this one for quite some time, and a new genus name is required to maintain monophyletic genera (or to avoid merging a bunch of very distinctive, long-standing genera.”

Comments from Robbins: “YES. This seems like a straightforward proposal given our current understanding. So, I vote yes for placing both taxa in the new genus.”

Comments from Bonaccorso: “YES. Given their phylogenetic affinities and their lack of close relationship with “real” Philydor species, it makes sense to give them a new genus name.”

Comments from Stiles: “YES for reasons clearly stated in the proposal and supported by various comments from other SACC members (and others).”

Comments from Lane: “YES. The phylogenetic reconstruction seems to necessitate the recognition of this new genus.”

Comments from Areta: “YES [for reasons given in the proposal].”

Comments from Jaramillo: “YES [for reasons given in the proposal].”

Comments from Zimmer: “YES, for reasons stated in the Proposal. We already knew that traditional Philydor was polyphyletic, and therefore, untenable. In this case, the recognition of a new genus for this clade is far preferable to merging the two species involved into either Megaxenops or Anabaxenops, not only because the exact affinities of the clade are unresolved due to conflicting data sets, but also because the clade has been shown to be highly divergent from either of the two putative closest genera. To merge erythrocercum and fuscipenne into either of these long-recognized genera, would, in my opinion, be the epitome of trying to force a square peg into a round hole, diluting the cohesiveness and informative value of either Megaxenops or Anabaxenops.”