Myrmotherula paraensis transitiva Hellmayr, 1929

Isler, Morton L., Chesser, R. Terry, Stryjewski, Katherine Faust & Whitney, Bret M., 2025, Systematics of three pan-Amazonian antwren lineages (Aves: Passeriformes: Thamnophilidae: Myrmotherula and Isleria), Zootaxa 5722 (1), pp. 45-78 : 56

Myrmotherula paraensis transitiva Hellmayr, 1929

Includes the study subpopulation designated transitiva in the analysis.

Diagnosis. Myrmotherula paraensis transitiva is distinguished from M. p. paraensis and M. p. ochrogyna by diagnosable differences in female plumage provided in the description of M. paraensis .

Distribution. Brazil east of the Rio Madeira, north of southern Amazonian forest limits, and west of the Rio Teles Pires. Northern limits are uncertain.

Remarks. This subpopulation is considered a subspecies of M. paraensis , rather than a species, based on the absence of vocal differences with the nominate form. In the companion genetic analysis, subclades containing individuals of M. p. transitiva and M. p. ochrogyna were not geographically based. Female plumage appears to differ between transitiva and paraensis , but additional specimen and vocal data are needed from the Madeira- Tapajós interfluvium to substantiate their maintenance as subspecies. The genetic data in the companion paper indicate that ochrogyna/transitiva is more closely related to M. garbei than M. paraensis , but these results are poorly supported and based solely on mtDNA ( Chesser et al. 2025).