A new species of the genus Tetragonopterus Cuvier, 1816 (Ostariophysi: Characiformes: Characidae) from the rio Tocantins drainage, Brazil

A new species of the genus Tetragonopterus is described from specimens of the upper and middle portions of the rio Tocantins drainage. The new species can be distinguished from all congeners by the possession of a very uniquely shaped maxilla.