Its species are native to Southeast Asia and Melanesia.

The genus Tanygnathus was introduced by the German naturalist Johann Wagler in 1832.

[1] The type species was subsequently designated as the great-billed parrot (Tanygnathus megalorynchos) by the English zoologist George Robert Gray in 1840.

[2][3] The name Tanygnathus combines the Ancient Greek words tanuō "to stretch out" and gnathos "jaw".

[4] The genus contains five species:[5] Genetic analysis has supported reclassifying all 4 species under Psittacula, making Tanygnathus a synonym of the former genus.