Asemospiza, Burns, Kevin J., Unitt, Philip & Mason, Nicholas A., 2016

Burns, Kevin J., Unitt, Philip & Mason, Nicholas A., 2016, A genus-level classification of the family Thraupidae (Class Aves: Order Passeriformes), Zootaxa 4088 (3), pp. 329-354 : 334

7. Asemospiza , new genus ( Fig. 2 )

Type species. Fringilla fuliginosa Wied, 1831 , currently recognized as Tiaris fuliginosus .

Included species. Asemospiza fuliginosa (Wied, 1831) and A. obscura (d’Orbigny & Lafresnaye, 1837), the latter currently recognized as T. obscurus . Because the name Asemospiza is feminine in gender and Tiaris is masculine, the endings of the adjectival specific epithets change, as do the following adjectival subspecific names: T. f. fuliginosus becomes A. f. fuliginosa , T. f. fumosus (Lawrence, 1874) becomes A. f. fumosa, T. o. obscurus becomes A. o. obscura , and T. o. pacificus (Koepcke, 1963) becomes A. o. pacifica. Other subspecific names currently used in this genus are invariable.

Diagnosis. Like several other species within Coerebinae, these two species have small conical bills. However, neither A. fuliginosa nor A. obscura has the markings of many of these species. They lack the yellow facial markings found in Tiaris olivaceus and Phonipara or the greenish upperparts found in Melanospiza bicolor and Loxipasser Bryant, 1866 . They also lack the orange to reddish facial markings of the bullfinches (Pyrrhulagra portoricensis , P. violacea , and Loxigilla Lesson, 1831 ), which are also conical-billed species classified in the Coerebinae. Instead, the two species of Asemospiza are mostly unmarked. Males of A. fuliginosa are uniformly black, but differ thus from the other species in Coerebinae that are mostly black: they lack the pink feet of Melanospiza , the white wing markings of Pyrrhulagra nigra , or the white undertail markings of Geospiza . Females of A. fuliginosa and A. obscura are similar to each other: both are unpatterned, mostly brown, and slightly darker above than below. In addition to these morphological characters, we have identified 10 unreversed molecular synapomorphies across two genes (numbered by their position in the gene alignment). These are, for cyt b: C147G, C195T, C325T, C358A, A417G, and C750T; for ND2: C211T, C345T, C367T, C507A. The two species are also the only members of the Coerebinae restricted to South America. Cladistically, we define this genus as the descendants of the common ancestor of Asemospiza fuliginosa and A. obscura .

Etymology. Asemospiza is formed from the Greek ἄσηΜος, “unmarked,” in reference to the unstreaked drab plumage of the two component species, and Greek σπίζα, the chaffinch Fringilla coelebs , commonly used in ornithology in the coining of names of finch-like birds. Its gender is feminine, in accord with Greek grammar.

Comments. The genus Tiaris Swainson, 1827 (type = Tiaris pusillus Swainson, 1827 , currently Tiaris olivaceus ), includes five species representing four distinct clades within the subfamily Coerebinae ( Fig. 2 ). No species or set of species of Tiaris forms an exclusive clade with the type species; hence we make this recommendation and recommendations 4, 5, and 6 above. Two of the five species, T. fuliginosus and T. obscurus , form a strongly supported monophyletic group (PP = 1.0, ML bootstrap = 100%) and are geographic replacements of each other (Bates 1997). These two species form the sister clade to the Darwin’s finches (PP = 1.0, ML bootstrap = 71%). Therefore, unless these two species are merged into a broad genus that includes all the Darwin’s finches, a new genus is needed for their clade, and there being no generic name available, we provide Asemospiza for this purpose.

Figures

FIGURE 2. Maximum clade credibility tree from the Bayesian analyses of Burns et al. (2014). Subfamilies Coerebinae and Tachyphoninae shown. Labeling and format as in Fig. 1.