Proposal (230) to South American Classification Committee

 

Change linear sequence of genera in Trogonidae

 

Background: The traditional classification (e.g., AOU 1998) of New World Trogonidae uses the following linear sequence of genera:

 

Priotelus [extralimital]
Trogon
Euptilotis
[extralimital]
Pharomachrus

 

I'm not sure if any explicit rationale has ever been published to justify this traditional linear sequence, but I suspect that placement of quetzals at the end reflects a traditional view of "biggest = latest " pattern of evolution within a group.

 

New information: Moyle (2005) analyzed nuclear (RAG-1) and mitochondrial (ND2) DNA sequences to produce a phylogeny for the family as a whole, with all genera, including Old World Apaloderma and Harpactes, and 32 species-level taxa to produce a phylogenetic hypothesis for the family. Moyle's most startling result was that the quetzals (Pharomachrus and Euptilotis) and Priotelus were probably basal to all other genera, including the Old World ones. Support for the quetzals as basal was not strong (171% Bayesian and maximum-likelihood bootstrap 57%).

 

A linear sequence that reflects Moyle's phylogenetic hypothesis would be:

 

Euptilotis [extralimital] *
Pharomachrus
Priotelus
[extralimital] 
Trogon

 

Euptilotis is basal to the three species of Pharomachrus (1.00 Bayesian, 100% bootstrap); although P. mocinno was not included, its absence is highly unlikely to alter that relationship.

 

Analysis: See Moyle (2005) for discussion of the support for the basal position of the quetzals (ask me for a pdf if needed) and for conflicts with a previous analysis (Espinoza del los Monteros 1998).

 

Recommendation: Moyle's data set and analysis are clearly superior to any previous data and should be reflected in our linear sequence, and I strongly recommend a YES vote to change our sequence to the one above, which involves for SACC the trivial flip-flopping of Pharomachrus and Trogon.

 

Literature cited:

 

Espinosa de los Monteros, A. 2000. Higher-level phylogeny of Trogoniformes. Molecular Phylogenetics and Evolution 15:20-34.

 

Moyle, R. G. 2005. Phylogeny and biogeographical history of Trogoniformes, a pantropical bird order. Biological J. Linnean Society 84:725-388.

 

Van Remsen, August 2006

Note: This proposal is a slight modification of the one to AOU/NACC. It was accepted by NACC - see Banks et al. (2006).

 

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Comments from Stiles: "YES. Also fits with the tendency of many more derived taxa to have speciated more extensively and/or recently (e. g., Tyrannus)."

 

Comments from Robbins: "YES. But I suspect we have not seen the definite word on what is the basal clade in Trogonidae."

 

Comments from Jaramillo: "YES.  It is interesting that the basal trogons are Caribbean. The Caribbean obviously has many secrets it is still hiding from us."

 

Comments from Pacheco: "YES. A posio de Pharomachrus frente, no tratamento tradicional, talvez tenha origem meramente fortuita, por constar no topo do "Key to the genera of Trogonidae de Ridgway (1911. The birds of North and Middle America). O presente trabalho de Moyle (mais que) suficiente para reposicionar Pharomachrus."