Evolution and systematics

The exact affinities of the sharpbill (Oxyruncus cristatus) have been in dispute since the genus Oxyruncus was first described in 1820. Since the late nineteenth century most authors have given the sharpbill family status, despite its widely scattered distribution. Sharpbills are obviously related to the tyrannid passerines, particularly the tyrant flycatchers, cotin-gas, and manakins. However, the sharpbills' exact relations with these groups remain unclear.

In the 1980s, genetic comparisons seemed to indicate that sharpbills are cotingas and also are closely related to tityras and becards. However, for the purposes of this discussion the sharpbills are treated as a separate family (Oxyruncidae) within the Passeriformes as per Peters checklist.

This monotypic family has been divided into five races, differentiated slightly by color and size, but mainly by their distribution. Oxyruncus cristatus frater, the Costa Rican sharpbill, ranges from northeastern Costa Rica to western Panama, where it is known by its Spanish name, Pico Agudo. O. c. brooksi is found in the Darien region of Panama. O. c. hy-poglaucus inhabits the highlands of southern Venezuela, Guyana, and Suriname. O. c. cristatus and O. c. tocantinsi are both found in Brazil (the latter may be synonymous with O. c. hypoglaucus).

0 0

Post a comment