Rhynchocyclus

Rhynchocyclus
Western olivaceous flatbill (R. aequinoctialis)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Tyrannidae
Genus:	Rhynchocyclus Cabanis & Heine, 1860
Type species
Cyclorhynchus olivaceus Desmarest=Platyrhynchos olivaceus Temminck
Species
5, see text
Synonyms
Cyclorhynchus Sundevall, 1836 (non Kaup, 1829: preoccupied)

Rhynchocyclus is a genus of passerine birds in the tyrant flycatcher family Tyrannidae.

Taxonomy

The genus Rhynchocyclus was introduced in 1860 by the German ornithologists Jean Cabanis and Ferdinand Heine as a replacement name for Cyclorhynchus that had been introduced in 1836 by Carl Jakob Sundevall. ^{[1] [2]} The name Cyclorhynchus was preoccupied by Cyclorrhynchus that had been introduced in 1829 by Johann Jakob Kaup. ^[3] The type species is Cyclorhynchus olivaceus Desmarest which is a junior synonym of Platyrhynchos olivaceus Temminck, the eastern olivaceous flatbill. ^{[4] [5]} The genus name Rhynchocyclus is an anagram of the original name Cyclorhynchus. ^[6] The latter combines the Ancient Greek κυκλος/kuklos meaning "circle" or "shield" with ῥυγχος /rhunkhos meaning "bill". ^[7]

The genus contains five species: ^[8]

Image	Scientific name	Common Name	Distribution
	Rhynchocyclus brevirostris	Eye-ringed flatbill	Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama, with a slight incursion into Colombia
	Rhynchocyclus pacificus	Pacific flatbill	Colombia and Ecuador.
	Rhynchocyclus olivaceus	Eastern olivaceous flatbill	Brazil, Colombia, French Guiana, Guyana, Suriname, and Venezuela.
	Rhynchocyclus aequinoctialis	Western olivaceous flatbill	Bolivia, Colombia, Ecuador, Panama, Peru, and Venezuela.
	Rhynchocyclus fulvipectus	Fulvous-breasted flatbill	Bolivia, Colombia, Ecuador, Peru, and Venezuela.

References

1. Cabanis, Jean; Heine, Ferdinand (1860). Museum Heineanum : Verzeichniss der ornithologischen Sammlung des Oberamtmann Ferdinand Heine, auf Gut St. Burchard vor Halberstadt (in German). Vol. 2. Halberstadt: R. Frantz. p. 56.
2. Sundevall, Carl Jakob (1835). "Ornithologiskl System". Kungliga Svenska Vetenskapsakademiens Handlingar. Series 3 (in Swedish). 23 (published 1836): 43-130 [83].
3. Kaup, Johann Jakob (1829). Skizzirte Entwickelungs-Geschichte und natürliches System der europäischen Thierwelt (in German). Darmstadt: Carl Wilhelm Leske. p. 155.
4. Gray, George Robert (1840). A List of the Genera of Birds : with an Indication of the Typical Species of Each Genus. London: R. and J.E. Taylor. p. 31.
5. Traylor, Melvin A. Jr, ed. (1979). Check-List of Birds of the World. Vol. 8. Cambridge, Massachusetts: Museum of Comparative Zoology. pp. 97–98.
6. Jobling, James A. "Rhynchocyclus". The Key to Scientific Names. Cornell Lab of Ornithology. Retrieved 22 May 2025.
7. Jobling, James A. "Cyclorhynchus". The Key to Scientific Names. Cornell Lab of Ornithology. Retrieved 22 May 2025.
8. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (February 2025). "Tyrant flycatchers". IOC World Bird List Version 15.1. International Ornithologists' Union. Retrieved 22 May 2025.