[2] The species' English name and specific epithet commemorate the German naturalist Johann Baptist von Spix (1782-1826).

[4] The previous name "chicli spinetail" is supposedly onomatopeoic, but does not resemble the species' song.

Their tail is dark brown; it is graduated and the central feathers have pointed tips.

[5][6][7] Spix's spinetail is found from Minas Gerais and Espírito Santo in southeastern Brazil south through eastern Paraguay and essentially all of Uruguay into Argentina as far as Buenos Aires Province.

It inhabits a wide variety of landscapes in the Atlantic Forest biome, where it tends to stay low in dense undergrowth.

Examples include fields and pastures, gallery forest, campo rupestres, restinga, savanna, and brushy second growth.

[5] The breeding season of Spix's spinetail has not been fully defined but includes November to February.

Its nest is an elongated dome of spiny sticks with a long lateral entrance tube, placed in a shrub or bush up to about 2 m (7 ft) above the ground.

The inner chamber is lined with softer material such as moss, hair, and small leaves, and almost always shed skins of snakes and lizards.

The song of Spix's spinetail has been described as "a five syllable phrase, last four notes with bubbling quality: sweet!