Proposal (819) to South American Classification Committee

Resurrect the genus Dendroma Swainson 1837 for Philydor erythropterum and P. rufum

Derryberry et al. (2011, Evolution 65: 2973-2986) found Philydor to be polyphyletic. One of the problems is that Philydor erythropterum and P. rufum are sister to Ancistrops strigilatus, and together they are not even closely related to other Philydor but closer to the Clibanornis/Automolus clade.

Option A. One solution would be to resurrect the genus Dendroma Swainson 1837, whose type (by subsequent designation) is Sphenura poliocephala Lichtenstein = Dendrocopos rufum Vieillot. This option will leave A. strigilatus in its own monotypic genus as usual. Being Dendroma derived from the Greek dendron tree and -dromos –runner (Jobling 2010 The Helm dictionary of scientific bird names) with a feminine suffix, the name is feminine in gender and the new combinations would be Dendroma rufa and Dendroma erythroptera.

Option B. Alternatively, we can merge these three species in the same genus. Although they lack the striped plumage of strigilatus, erythropterum and rufum share two traits that make the expanded genus cohesive: a bill with an apical hook (although not strongly developed in some subspecies of rufum), and rufous wings. P. erythropterum has also stripes on its crown. A. strigilatus and P. erythropterum are so similar that are easily confused in the field, although they forage in different microhabitats (Parker 1979. An introduction to foliage-gleaner identification. Continental Birdlife 1:32–37). On the other hand, this expanded genus would be a very old genus compared to other genera of foliage gleaners, although there are other furnariid genera such as Xenops, Dendrocincla, the new Sylviorthorhynchus, Geositta and Sclerurus that are even older. In addition, because Dendroma Swainson 1837 is older than Ancistrops Sclater 1862, the former would be the name of the expanded genus and would result in additional nomenclatorial changes: the new combination Dendroma strigilata.

I recommend resurrecting the genus Dendroma only for rufum and erythropterum and keeping strigilatus in Ancistrops (Option A).

[Thanks Dick Schodde for advise on nomenclature]

Santiago Claramunt, May 2019

Note from Remsen on voting procedure: A YES vote is for Option A. A NO vote is for Option B or some other unspecified option.

Comments from Remsen: “YES. An arbitrary decision given phenotypic similarities among the three, but looking at the calibrated phylogeny above, treating Ancistrops as separate from Dendroma appears to me to be the better decision.”

Comments from Stiles: “YES for reviving Dendroma for these two species, and leaving the more distantly related Ancistrops monospecific. (I note from the phylogeny that the genus Philydor remains polyphyletic, with two species probably in Anabacerthia and two other pairs of species, at least one of which might require a new name.. so here, over to Santiago!”

Comments from Robbins: “YES, given the branch length between Ancistrops and erythropterum/rufum and comparing to long-recognized genera, it seems the best course is to resurrect Dendroma for those two foliage-gleaners.”

Comments from Pacheco: “YES. I consider the option to resuscitate Dendroma is a good solution to balance molecular and phenotypic data.”

Comments from Zimmer: “YES” for Option A – retain Ancistrops and resurrect Dendroma for rufa & erythroptera (as they would then be called). Ancistrops is just a bit too different (in plumage pattern, bill morphology, vocalizations, and foraging behavior) from the other foliage-gleaners for me to be comfortable in lumping the three species into a single genus, and, as others have noted, the relative branch length of Ancistrops places it as older than just about all of the other foliage-gleaners.”

Comments from Jaramillo: “A YES – resurrect Dendroma for these two species.”