Discosura is a genus of South and Central American hummingbirds in the family Trochilidae. The thorntails are sometimes placed in the genus Popelairia (Reichenbach, 1854), leaving Discosura for the racket-tipped thorntail. On the contrary, some have argued for merging this genus into Lophornis, which they overall resemble, except for the highly modified tail-feathers of the males.

Taxonomy

The genus Discosura was introduced in 1850 by the French naturalist Charles Lucien Bonaparte. Bonaparte did not specify a type species but this was designated as the racket-tipped thorntail by George Robert Gray in 1855. The genus name combines the Ancient Greek diskos meaning "plate" with oura meaning "tail".

The genus contains five species.

Genus Discosura – Bonaparte, 1850 – five species
Common nameScientific name and subspeciesRangeSize and ecologyIUCN status and estimated population
Wire-crested thorntail Male FemaleDiscosura popelairii (Du Bus de Gisignies, 1846)Colombia, Ecuador and PeruSize: Habitat: Diet:LC
Black-bellied thorntail FemaleDiscosura langsdorffi (Temminck, 1821) Two subspecies D. l. langsdorffi (Temminck, 1821)D. l. melanosternon (Gould, 1868)Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela.Size: Habitat: Diet:LC
Letitia's thorntailDiscosura letitiae (Bourcier & Mulsant, 1852)Probably Bolivia (only known from two old specimens of uncertain origin)Size: Habitat: Diet:LC
Green thorntail Male FemaleDiscosura conversii (Bourcier & Mulsant, 1846)Costa Rica to EcuadorSize: Habitat: Diet:LC
Racket-tipped thorntail MaleDiscosura longicaudus (Gmelin, JF, 1788)Brazil, French Guiana, Guyana, Suriname, and southern VenezuelaSize: Habitat: Diet:LC