Pheidole obscurior

Identification
Similar species are Pheidole cardinalis and Pheidole susannae. Majors of P. obscurior have the vertexal surface smooth, while in P. cardinalis it is sculptured. In addition, the pronotal dorsum of P. obscurior is strongly areolate, with few rugulae in majors, and with a combination of few standing flexuous and comparatively longer hairs, with dense, shorter, thin and apically curved hairs; while the pronotal surface of P. susannae is finely areolate in majors, bearing standing hairs only. Finally, sympatric populations between both species are unknown.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 * . Pheidole susannae r. obscurior Forel, 1886b: xliv (s.w.) BRAZIL. Forel, 1893g: 410 (q.m.).
 * Junior synonym of susannae: Longino, 2009: 79.
 * Senior synonym of ovulata: Casadei-Ferreira, Economo & Feitosa, 2020: 12.
 * Senior synonym of partita: Casadei-Ferreira, Economo & Feitosa, 2020: 12.
 * Status as species: Wilson, 2003: 330; Casadei-Ferreira, Economo & Feitosa, 2020: 12.
 * evoluta. Pheidole incisa subsp. evoluta Borgmeier, 1929: 204, pl. 6, fig. 3 (s.w.) BRAZIL.
 * Junior synonym of susannae: Kempf, 1964e: 63.
 * Junior synonym of obscurior: Casadei-Ferreira, Economo & Feitosa, 2020: 12.
 * partita. Pheidole partita Mayr, 1887: 590 (s.), 604 (w.) BRAZIL.
 * Junior synonym of susannae: Longino, 2009: 79.
 * Junior synonym of obscurior: Wilson, 2003: 330; Casadei-Ferreira, Economo & Feitosa, 2020: 12.

Taxonomic Notes
In previous studies (Forel 1886; Wilson, 2003), the authors recognized that differences between P. obscurior and Pheidole susannae were mainly related to the color pattern. Longino (2009) synonymized P. obscurior under P. susannae considering that the color pattern is variable in this widespread species. However, P. obscurior presents a very distinct pilosity pattern and pronotal sculpture, which was not recognized by previous authors. The same pilosity pattern and the overall morphology of P. obscurior is shared with Pheidole partita and Pheidole incisa evoluta. We revive Pheidole obscurior to species with P. partita and P. incisa evoluta as its junior synonyms.