Proposal (638) to South American Classification Committee
Recognize
the genus Cercomacroides
(Thamnophilidae)
Effect on SACC: This proposal is for the recognition of a newly described
genus for several species currently classified in Cercomacra.
Background: Current SACC footnote 39e summarizes the situation:
“Fitzpatrick &
Willard (1990) and Zimmer & Isler (2003) considered Cercomacra tyrannina, C. laeta,
C. parkeri, C. nigrescens, and C. serva form a
monophyletic group based on plumage and voice. Tello et al. (2014) confirmed
the monophyly of this group and also showed that they are not the sister group
to other Cercomacra, thus requiring
the naming of a new genus, Cercomacroides,
for them. SACC
proposal badly needed.”
Analysis and recommendation: Tello et al. (2014) named a new genus, Cercomacroides, for the species in the “tyrannina group”
(whistlers), to include the following taxa:
nigrescens
laeta
parkeri
tyrannina (type)
serva
Their molecular data set included three
mitochondrial (ND2, ND3, CYTB)
and one nuclear intron (FIB5) for a
total of 3018 bps. Tello et al.’s ongoing investigation on the systematics of
this group has produced ~5k additional nucleotides (including several nuclear
introns) that corroborated the monophyly of Cercomacroides
and helped resolved problematic basal nodes within both, Cercomacroides and Cercomacra.
I recommend a YES vote. Morphological
similarities that support the monophyly of Cercomacra
are vague and maybe plesiomorphic, whereas the recognition of Cercomacra and Cercomacroides as different genera is consistent with plumage,
behavioral, and ecological differences (Zimmer and Isler 2003) and is required
to retain the monophyly of Cercomacra (s.s.).
Recognizing Cercomacroides as a genus
is the appropriate taxonomic solution for this particular case.
References:
Fitzpatrick J.W., Willard D. E., 1990. Cercomacra manu, a new species of antbird from Southwestern
Amazonia. Auk 107:
239-245.
Tello, J. G., Raposo, M., Bates, J.,
Cadena, D., Bravo, G., and M. Maldonado. 2014.
Reassessment of the systematics of the widespread Neotropical genus Cercomacra (Aves, Thamnophilidae).
Zoological Journal of the Linnean Society 170, 546-565.
Zimmer, K. J., and Isler, M. L., 2003. Family Thamnophilidae
(Typical antbirds). Handbook of the Birds of the World Vol. 8, 448-681.
Jose G. Tello, August 2014.
======================================================
Comments
from Remsen: “YES.
The new data from Tello et al. (2014) require splitting of Cercomacra. Although this genus has long been known to consist
of two distinct groups, now we know they are not sister groups.”
Comments from Zimmer: “YES” for reasons
spelled out in the proposal. As Van
commented, we’ve long known there were two distinct groups within Cercomacra (based on plumage, vocalizations,
ecology and behavior), but what has changed is that we now have genetic data
showing that the two groups are not sisters.
Erection of the new genus and transfer of the “tyrannina-group” is
required to keep Cercomacra as a
monophyletic genus.”
Comments from Stiles: “YES, given the polyphyly of Cercomacra and the fact that including
the intervening genera in an expanded Cercomacra
would produce an undiagnosable soup, recognizing Cercomacroides is clearly desirable.”
Comments
from Jaramillo: “YES
– The molecular data matches up well with morphological, and ecological data to
clarify that these two groups are different. But more importantly, they are not
sisters, needing the change of part of Cercomacra
to Cercomacroides.”
Comments
from Stotz: “YES. Not completely intuitive split, but the two
subunits of Cercomacra have always
been clearly defined, and this split is consistent with those units based on
voice and to a lesser extent plumage. So
I am confortable with the split, even though I am surprised that the two groups
are not sister.”
Comments
from Pacheco: “YES, with
strong evidence, well presented in the work of Pepe and colleagues.”