Thrush-like Mourner (Schiffornis turdina) - HBW 9, p. 168

Taxonomy: Muscicapa turdina Wied, 1831, Bahia, Brazil.
Systematic position of genus uncertain. Analysis of 19 characters, mostly anatomical, suggested that it is a member of a monophyletic assemblage of six superficially very diverse genera currently divided among Cotingidae, Tyrannidae and the present family; also, recent analyses of genetic data resulted in its grouping with the genera Pachyramphus and Tityra (both at present provisionally placed in Tyrannidae) in a “tityrine clade”; traditional placement in present family almost certainly inappropriate, but retained pending further study. Present species forms a superspecies with S. virescens. Geographical variation involves both plumage and voice; pale and dark forms, as well as upland and lowland ones, occur, and situation especially complex in NW South America and adjacent Panama; possible taxonomic significance of vocal differences not understood; races probably constitute more than one species, but critical studies not yet undertaken. Thirteen subspecies recognized.