Nesomyrmex sellaris

This species is widely distributed in East Madagascar. The known samples were collected in diverse habitats from tropical dry forests to rainforests, typically at lower elevation from 20–1130 m. (Csösz & Fisher 2016)

Identification
A member of the brevicornis species-group.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  sellaris. Nesomyrmex sellaris Csösz & Fisher, 2016: 156, figs 42-45 (w.) MADAGASCAR.

Worker
Body color: yellow. Body color pattern: concolorous. Absolute cephalic size: 449 [410, 557]. Cephalic length vs. maximum width of head capsule (CL/CWb): 1.18 [1.13, 1.25]. Postocular distance vs. cephalic length (PoOc/CL): 0.51 [0.49, 0.53]. Postocular sides of cranium contour frontal view orientation: converging posteriorly. Postocular sides of cranium contour frontal view shape: broadly convex. Vertex contour line in frontal view shape: straight. Vertex sculpture: main sculpture absent, ground sculpture imbricate, shiny. Setal pits on head dorsum: surrounded by conspicuous foveae with well demarcated margins. Diameter of foveae on head dorsum: 10–15 μm. Gena contour line in frontal view shape: straight. Genae contour from anterior view orientation: converging. Gena sculpture: rugoso-reticulate with areolate ground sculpture. Concentric carinae laterally surrounding antennal foramen: present. Eye length vs. absolute cephalic size (EL/CS): 0.24 [0.23, 0.26]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.29 [0.27, 0.30]. Longitudinal carinae on median region of frons: absent. Smooth median region on frons: present. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.69 [0.65, 0.72]. Median clypeal notch: present. Ground sculpture of submedian area of clypeus: present. Median carina of clypeus: absent. Metanotal depression: present. Dorsal region of mesosoma sculpture: imbricate, main sculpture absent. Lateral region of pronotum sculpture: imbricate, main sculpture absent; inconspicious areolate ground sculpture, main sculpture dispersed costate. Mesopleuron sculpture: ground sculpture areolate, main sculpture absent. Metapleuron sculpture: ground sculpture areolate, main sculpture absent. Petiole width vs. absolute cephalic size (PEW/ CS): 0.21 [0.20, 0.23]. Dorsal region of petiole sculpture: ground sculpture areolate, main sculpture absent. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.29 [0.26, 0.31]. Dorsal region of postpetiole sculpture: ground sculpture smooth, main sculpture absent. Surface of the first gastral tergite: incontinuously imbricate; continuously imbricate.

Type Material
Holotype: CASENT0428261, collection code: BLF02859, Réserve Spéciale de l’Ankarana, 22.9 km 224° SW Anivorano Nord, -12.90889°, 49.10983°, alt 80 m, Fisher, Griswold et al., 02.10.2001, (1w,, CASENT0428261); Paratypes: four workers from the same locality under CASENT codes: CASENT0422623, collection code: BLF02859, (1w, CASC); CASENT0422624, collection code: BLF02859, (1w, CASC); CASENT0428262, collection code: BLF02859, (1w, CASC); CASENT0422621, collection code: BLF2859, (1w, CASC).

Etymology
The name (sellaris) refers to the deep mesopropodeal depression in workers resembling a saddle (=sella Lat.).