Priority of names for “Anisognathus” mountain-tanagers
By Thomas Donegan
Three genera, all with different type species, were described for species that until now were considered part of Anisognathus within a period of no greater than 2 years. Anisognathus (type species: A. igniventris lunulatus) was illustrated by Reichenbach in the 1850 edition of Avium Systema Naturale. We have not been able to find reliable information on the actual date of publication of the plates. However, the accompanying text was not published until the edition of Handbuch der specieleln Ornithologie that was published, according to its face, on 1 October 1852. Berlepsch (1893) considered the genus name Anisognathus as published in 1850 publication to be a nomen nudum due to the lack of compliance of the plates volume with the requirements for a genus description. On some interpretations the name Anisognathus would be considered not to have been published until 1 October 1852.
The genera Compsocoma (type species: A. somptuosus victorini) and Poecilothraupis (type species: A. i. igniventris) were both described by Cabanis in the “1850/1851” edition of Museum Heineanum. It is evident that Cabanis and Reichenbach were working independently owing to this contemporaneous publication. Zimmer (1926) considered that pp. 1-32 of Cabanis (which includes the description of Compsocoma) were 'in circulation' in late 1850 - at a time when such circulation was valid publication for purposes of ICZN Rule 21.8. Browning & Monroe (1991) considered the date of actual publication to be 15 October 1850 for pages 1-24 and 31 December 1850 for the rest. S. Gregory and E. Dickinson (in litt. 2007) consider just pp. 25-104 (including Compsocoma) to be published in 1850 and that the rest (pp. 105-233, including Poceilothraupis) were published at some point in 1851. The preface to the "1850/1851" edition is dated October 1851, meaning that an earlier publication date is unlikely and current rules would provide for a publication date of 31 October 1851 in the absence of other evidence.
On all analyses except those based on the date of Reichenbach’s plate, the names Compsocoma Cabanis and Poecilothraupis Cabanis would be senior to the name Anisognathus Reichenbach. The names Poecilothraupis and Compsocoma were used widely in (early to mid) 20th century publications for the two groups treated as sub-genera in this paper. As a result, there is no required reversal to the Principle of Priority in favour of preserving the name Anisognathus.
The case for Compsocoma and Poecilothraupis both being resurrected requires further consideration. "Anisognathus" as presently constituted is among the most ecologically and morphologically heterogeneous of Tanager genera that divides into two well-defined groups (Isler & Isler 1999, Bleiweiss 2008). Although the two genera would be rather small, both lacrymosus and somptuosus contain several phylogenetic and probably biological species, so there are likely in future to be more species in them than under current treatments. Despite Poecilothraupis most likely having priority, we continue with the status quo of using Anisognathus herein. Due to the lack of good information on publication dates, the issue of priority between Anisognathus, Compsocoma (if not split) and Poecilothraupis may benefit most from Commission attention (to consider fixing dates or suppressing a name) rather than from particular views being taken on priority that might cause nomenclatural instability.
Browning MR, Munroe BL Jr. 1991. Clarifications and corrections of the dates of issue of some publications containing descriptions of North American birds. Arch. Nat. Hist. (1991) 18:389.
Donegan, T.M. & Avendaño, J.E. 2010. A new subspecies of mountain tanager in the Anisognathus lacrymosus complex from the Yariguíes Mountains of Colombia. Bull BOC 130(1): 13-32.
Other papers are cited in the latter.