Sapayoa
The sapayoa or broad-billed sapayoa is a suboscine passerine bird found Colombia, Ecuador, and Panama.
Taxonomy and systematics
As the sapayoa's specific epithet aenigma implies, its relationships have long been elusive.The sapayoa was formally described by the German ornithologist Ernst Hartert in 1903 under the present binomial name Sapayoa aenigma.
It has always been considered a monotypic genus, Sapayoa, and historically regarded as a New World suboscine; in particular, it was assigned to the manakin family. However, the species was listed as incertae sedis in the Sibley-Ahlquist taxonomy, because
"preliminary DNA-DNA hybridization comparisons... indicate that this species is either a relative of the Old World Eurylaimidae or a sister group of all other Tyrannida, as suggested by earlier biochemical studies.... In any event, it is not a close relative of manakins or any other recent tyrannoid."
More recent research suggests that it is not a New World suboscine at all, but an Old World suboscine. In 2004, it was shown that the sapayoa is an outlier to the New World suboscines. In an earlier analysis based on nDNA myoglobin intron 2 and GAPDH intron 11 sequence data, the authors found the sapayoa
"as a deep branch in the group of broadbills and pittas of the Old World tropics."
Accordingly, the sapayoa would be the last surviving New World species of a lineage that evolved in Australia-New Guinea when Gondwana was in the process of splitting apart. The sapayoa's ancestors are hypothesized to have reached South America via the Western Antarctica Peninsula.
Beginning in about 2010, major taxonomic systems moved the sapayoa into its own family Sapayoidae. However, they differ in its placement in a linear sequence of families. The International Ornithological Committee places it second among passerine families, between Acanthisittidae and Philepittidae. The Clements taxonomy places several other families between the New Zealand wrens and the sapayoa and follows it with the asities. BirdLife International's Handbook of the Birds of the World places it further down the linear sequence, between Eurylaimidae and Calyptomenidae.
All the systems agree that the sapayoa is monotypic.