T[yrannus] Rufiventris (protonym) The chocolate-vented tyrant (Neoxolmis rufiventris) is a species of bird in the family Tyrannidae.

The species was first scientifically described by Vieillot in 1823.

It breeds in southern Argentina, Chile and Tierra del Fuego; during the austral winter it migrates north to the Pampas.

Its natural habitat is temperate grassland.

This article about a tyrant flycatcher is a stub.