Perhaps the most intriguing of the Sibley & Monroe (1990) splits was their elevation of the Broad-billed Sapayoa Sapayoa aenigma to family level status as "Incertae Sedis" [latin for "we don't know where the hell it goes".... I'm paraphrasing]. They state that "preliminary DNA-DNA hybridization comparisons ... indicate that this species is either a relative of the Old World Eurylaimidae [broadbills] or a sister group of all other Tyrannida [flycatchers and relatives], as suggested by earlier biochemical studies... In any event, it is not a close relative of manakins or any other recent tyrannoid." It turns out, now 15 years later, that the Sapayoa (there is no other type, so no need for "Broad-billed") is a relict suboscine from the broadbill assemblage of Asia and Africa (see below).
I can't show you a photo of the Broad-billed Sapayoa but it looks rather like an overgrown female manakin but with a broader bill and longer tail. I've scanned Guy Tudor's painting from Ridgely & Tudor (1994) to give the basic idea. I can show you a photo of the habitat of Sapayoa (left) in Panama. This is steaming lowland jungle along Pipeline Road in what used to be the "Canal Zone" [standing on the dilapidated bridge are Bay Area birders Joe Morlan (white hat) and Garth Alton (blue shirt)]. I recall finding the Sapayoa when I was alone inside the forest, chasing a mixed flock of antwrens, and it sat quietly in the flock in the undergrowth. Ridgely & Tudor (1994) remark of its unobtrusive behavior which they liken to flatbills; like them it sits quietly between making short sallies out for food.
Sapayoa is an inconspicuous, dull-colored bird of the forest understory
where it is rare to uncommon. It ranges from Panama to nw. Ecuador in tropical
lowlands, and favors ravines and small streams. It is usually found singly
or in pairs. Beyond this, rather little is known about this enigma (Ridgely
& Tudor 1994).
No one guessed that the Sapayoa was an Old World relict until biochemical evidence was obtained. Prum (1993) studied the phylogeny and biogeography of the asities and broadbills and presented evidence that the asities were just a subgroup of broadbills. Moyle et al. (2006) provided much DNA and other evidence that sorted out their true relationships. As it turns out, the broadbill stock arose perhaps 70 million years ago and for some time (perhaps 10 million years) evolved on India when it was still a huge isolated landmass in the Indian Ocean. When India first crashed into the Eurasian continent in the Paleocene, broadbills spread east (to southeast Asia) and west (to Africa) and in that very warm period, likely north as well. As climate cooled, presumably many species became extinct. Broadbills split into two main branches about 55 million years ago. One of those branches included the Eurylaimid Broadbills, the Sapayoa in the New World, and Asities. Sapayoa became isolated in the New World tropics about 52 million years ago (Moyle et al. 2006).
Thus Sapayoa shares a common ancestor with all broadbills and the asities
of Madagascar. One way to look at the evidence is to lump all of them in
one huge broadbill assemblage. Another way of handling the exact same evidence
is to create four families: the Calyptomenid Broadbills, the Eurylaimid
Broadbills, the Asities, and the Sapayoa. To retain Asities or Sapayoa
as a family, one must make all those splits. Making the four-way split,
and retaining Sapayoa as a family, is consistent with the way the South
American Checklist Committee (and this web site) handled a similar problem
with the barbet/toucan assemblage. They either had to be one huge family
(including toucans), or five separate families. SACC made the latter choice,
and I very much approve. I now handle the broadbill, asity, and Sapayoa
problem in the same way, a retain Sapayoa as a monotypic family of Old
World suboscines, isolated in the Neotropics.
Literature cited:
American Ornithologists' Union. 1983. Check-list of North American Birds. 6th ed. A.O.U., Washington, D. C.TOPAmerican Ornithologists' Union. 1998. Check-List of North American Birds. 7th ed. A.O.U., Washington, D. C.
Clements, J. 1991. Birds of the Word: a Checklist. 4th ed. Ibis Publ., Vista, CA.
Johansson, U.S., M. Irestedt, T.J. Parson, and P.G.P. Ericson. 2002. Basal phylogeny of the Tyrannoidea based on comparisons of cytochrome b and exons of nuclear C-MYS and RAG-1 genes. Auk 119:984-995.
Moyle, R.G., R.T. Chesser, R.O. Prum, P. Schikler, and J. Cracraft. 2006. Phylogeny and evolutionary history of Old World suboscine birds (Aves: Eurylaimides). Amer. Mus. Novitates 3544: 1-22
Prum, R. O., and W. E. Lanyon. 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91: 444-461.
Ridgely, R. S., and G. Tudor. 1994. The Birds of South America. Vol. 2: The Suboscine Passerines. Univ of Texas, Austin.
Sibley, C. G. 1996. Birds of the World, on diskette, Windows version 2.0. Charles G. Sibley, Santa Rosa, CA.
Sibley, C. G., and J. E. Ahlquist. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.
Sibley, C. G., and B. L. Monroe. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.