Diversification and species limits in scale-backed antbirds (<i>Willisornis</i>: Thamnophilidae), an Amazonian endemic lineage

Abstract The genus Willisornis is endemic to the Amazon Basin, inhabiting upland terra firme forest, with two species and seven subspecies currently recognized. Despite numerous systematic studies, a taxonomically-dense sampled phylogeny for still lacking, which, combined evidence of paraphyly gene flow between its recognized species, underscores uncertainty concerning limits evolutionary history genus. Here we present phylogenies population genetic analyses, including all taxa, relating them patterns plumage variation, reconstructing spatiotemporal context diversification in Our analyses have uncovered 13 independent lineages genus, monophyly named which also showed robust diagnoses. However, deeply coalesced were found within most no consistent variation was found. related hydrographic climate change cycles across Amazonia since Plio-Pleistocene, originating past one million years. Based on our findings, recommend recognition total six (one polytypic) based congruency