Proposal (275) to South American Classification Committee

Recognize the genus Epinecrophylla (Thamnophilidae)

Effect on SACC: This would recognize a newly described genus for several species currently classified in Myrmotherula.

Background & New information: Tiny, short-tailed thamnophilids have all been placed in a single genus, Myrmotherula, due to overall similarities in size and shape. Hackett & Rosenberg (1990), using protein electrophoresis, found the first evidence that the genus was not monophyletic. One of the groups that they identified as distinct from true Myrmotherula was the stipple-throated group, which share plumage similarities (Hackett & Rosenberg 1990), foraging similarities (dead-leaf specialists; Remsen & Parker 1984), and vocal similarities (Zimmer & Isler 2003). The genetic data of Irestedt et al. (2004), although very limited in its taxon sampling, also indicated that Myrmotherula was not a monophyletic group. Unpublished data from Robb Brumfield's ongoing phylogenetic analysis of the family, including 6 species from the stipple-throated group plus 12 other Myrmotherula, found that the two groups were not sisters (Isler et al. 2006).

Isler et al. (2006) named a new genus, Epinecrophylla, for the stipple-throated species, to include the following species:

fulviventris
gutturalis
leucophthalma
haematonota
fjeldsaai
spodionota
ornata
erythrura

Analysis and Recommendation: I vote YES because at this point there are no data other than vague morphological similarities to support the monophyly of Myrmotherula. Thus, with two independent genetic data sets that show that Myrmotherula is not monophyletic, and three phenotypic data sets that are consistent with the stipple-throated group as being a separate, monophyletic group, recognizing Epinecrophylla as a genus is the appropriate solution in terms of classification.

References:

HACKETT, S. J., AND K. V. ROSENBERG. 1990. Comparison of phenotypic and genetic differentiation in South American antwrens. Auk 107: 473-489.

IRESTEDT, M., J. FJELDSÅ, J. A. A. NYLANDER, AND P. G. P. ERICSON. 2004. Phylogenetic relationships of typical antbirds (Thamnophilidae) and test of incongruence based on Bayes factors. Bio Med Central Evolutionary Biology 4: 23.

ISLER, M. I., D. R. LACERDA, P. R. ISLER, S. J. HACKETT, K. V. ROSENBERG, AND R. T. BRUMFIELD. 2006. Epinecrophylla, a new genus of antwrens (Aves: Passeriformes: Thamnophilidae). Proceedings of the Biological Society of Washington 119:522-527.

REMSEN-PARKER. 1984. Condor 86: 36-41.

ZIMMER-ISLER. HBW chapter on Thamnophilidae.

Van Remsen, May 2007

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Comments from Stiles: "YES. Again, multiple data sets support this.  I´ll feel a bit better when the Brumfield et al. study is published, but current evidence is certainly consistent in this respect."

Comments from Cadena: "YES. The only thing that bothers me a little bit is that phylogenetic studies based on DNA sequences have only sampled six of the eight species that Isler et al. suggested should be transferred to Epinecrophylla (M. fjeldsaai and M. ornata are missing, although the latter was included in the allozyme study by Hackett and Rosenberg). But I guess we can take the behavioral, morphological and vocal data discussed by Isler et al. as evidence that these taxa belong in the clade."

Comments from Robbins: "YES, but like Gary I wish the Brumfield et al. data were published."

Comments from Nores: "YES. Hay una buena coincidencia entre los estudios moleculares entre sí y con los estudios de vocalizaciones y comportamiento de alimentación. Pienso que es un caso bien claro de que se trata de un género distinto, para el cual no había nombre disponible, ya que todas las especies fueron descriptas como Myrmotherula o Formicivora."

Comments from Zimmer: "YES. Molecular data are clear, and congruent with morphological, vocal, and ecological data sets. I am not bothered by the absence of fjeldsaai and ornata from the DNA sequence sampling - these two clearly belong with the other "stipple-throated" antwrens on the basis of vocal, ecological and morphological characters."

Comments from Pacheco: "YES. Dados reunidos por Isler et al.  são, em minha opinião, bem sucedidos em reforçar a correção de tratamento em separado para as até então "stipple-throated Myrmotherula".