Diversification and species limits in scale-backed antbirds (Willisornis: Thamnophilidae), an Amazonian endemic lineage Author Quaresma, Tânia Fontes Author Cronemberger, Áurea A. Author Batista, Romina Author Aleixo, Alexandre text Zoological Journal of the Linnean Society 2022 2022-04-20 196 4 1408 1430 http://dx.doi.org/10.1093/zoolinnean/zlac011 journal article 10.1093/zoolinnean/zlac011 0024-4082 1719CE06-0D0E-4E8E-94E8-37AC811AED10 WILLISORNIS POECILINOTUS GUTTURALIS ( TODD, 1927 ) Taxonomy Genetic lineages with plumage characteristics described below can be unequivocally assigned to W. p. gutturalis ( type locality: São Paulo de Olivença, on the south bank of the upper Amazon; Peters, 1951 ), distributed in south-western Amazonian Brazil and north-eastern Peru ( Gill et al. , 2022 ). Plumage attributes Males are similar to those of W. p. duidae lineages, but readily distinguished by a conspicuous a narrow black throat patch. Females are pale rufous above and below, paler underneath. ‘Lace’ similar as in males, in black−white colour. Tail pale rufous, with white spots in the middle part and on the terminal edges. Genetic differentiation Specimens with the plumage characteristics above belong to a highly distinct genetic lineages that is completely sorted for their mitochondrial DNA, but less so for the nuclear genes and which is distributed in a restricted area between the Juruá and Amazon/ Solimões rivers (Fig. 1). Plumage variation We have not identified conspicuous variations in plumage.