Many authorities lump this species with Plain Xenops but the HBW and Birdlife International Checklist has split that species into Plain Xenops X. genibarbis distributed in Central America and most of Northern South America and White-throated Xenops X. minutus on the basis of the latter's white throat and differences in the malar colouration and streaking on the breast. Vocalisations are different and there is also molecular evidence for the split. The White-throated Xenops is found in a variety of forest and woodland habitats in south-east Brazil and adjacent areas in Paraguay and Argentina. See the distribution map at Birdlife International.

It has a pale buff supercilium and a prominent white malar streak. Photo 1 shows the rufous rump and tail with black feathers (the 3rd and 4th retrices) showing in the tail and the rufous-tawny wing-band on the blackish wings.

It is unusual to see a Plain Xenops in a horizontal stance but I think this bird was close to its nest and was a bit concerned at our proximity. Photos 2 and 3 show different phases of a wing flashing display which might also have been territorial.

Like other xenops they behave a bit like piculets tapping at bark for insects and grubs and using holes in trees as nests.