Recently described Amazonian antwren. Males are gray with a bold white eyebrow and a black crown, wings, and tail. Females have white spots on a black crown and a rusty forehead. Found in humid forest, including seasonally flooded forest along big rivers and white sand forest, foraging from the middle levels to the canopy. Usually accompanies mixed-species flocks in the canopy. The song is a soft rolling trill. The rather similar male of the Aripuana Antwren has less black on the upperparts, and females have a paler forehead; Aripuana’s song is similar, but with fewer notes.