The Russet Antshrike, Thamnistes anabatinus, is a passerine bird in the antbird family. It is the only member of the genus Thamnistes.
It is a resident breeder in the tropical New World from southern Mexico to northern Bolivia.
It is a bird of forest, old second growth, semi-open woodland and edges up to 1500 m altitude. The female lays two brown-speckled white eggs in a deep cup nest 7-15 m high in a tree, usually in a semi-open location. Nest-building, incubation, and care of the young are shared by both sexes.
The Russet Antshrike is a small antbird, typically 14 cm long and weighing 21 g. It has a heavy hooked bill and brown upperparts becoming rufous on the wings and tail. There is a dark eyestripe and a buff supercilium. The underparts are olive buff. Sexes are similar, but the male has a concealed rufous-orange patch in the centre of his back. Young birds are similar to the adults, but have rufous fringes to the wing coverts and are paler below. The call is a squeaky sweek, and the song is cheep cheep CHEEP CHEEP cheep.
The Russet Antshrike feeds on insects and other arthropods, which it gleans from foliage like a vireo. It may be seen alone, in pairs, or with tanagers and warblers in mixed-species feeding flocks