The greater thornbird (Phacellodomus ruber) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae.

Their crown is reddish chestnut with pale streaks, their back rich reddish brown to olive-brown that sometimes becomes chesntut on the lower back, their rump a lighter rufescent brown, and their uppertail coverts chestnut.

[5][6][7] The greater thornbird is found in north-central and eastern Bolivia, from Bolivia east in Brazil to western Pernambuco and Bahia and south into Rio Grande do Sul, through central Paraguay into northern Argentina as far as Corrientes Province, and into western Uruguay.

[5][6][7] The greater thornbird breeds during the austral spring and summer, roughly September to January or beyond.

It makes a cone-shaped nest of thorny twigs and branches that can be about 60 cm (2 ft) high and 50 cm (2 ft) wide at its base, and lines an interior chamber with soft plant material and feathers.

It hangs the nest from a tree or shrub branch, usually 1 to 3 m (3 to 10 ft) above the ground, and often over water.

The greater thornbird's song is a "series of up to 20 loud, sharp, resounding notes, starting very high and explosive, thereafter slightly accelerating and gradually descending".