Thaumatomyrmex manni

Identification
Key to Thaumatomyrmex

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Colombia.

Nomenclature

 *  manni. Thaumatomyrmex manni Weber, 1939a: 99 (w.) BOLIVIA. Junior synonym of atrox: Longino, 1988: 38. Revived from synonymy: Fernández, 2008: 212 (in key); Jahyny, Lacau, et al. 2008: 336 (in key). See also: Kempf, 1975b: 123.

Description
Kempf (1975): holotype - TL 5.0 mm; HL 1.03 mm; HW 1.33 mm; CI 130; ML 1.43 mm: MI 139; IfW 0.81 mm; IfI 61; SL 0.97 mm; SI 95; WL 1.56 mm; PnW 0.68 mm; HfL 1.14 mm; HfI 86; PW 0.78 mm. Resembling very closely Thaumatomyrmex ferox and Thaumatomyrmex atrox, but exhibiting the following differences from both species:

Of larger size (cf. absolute measurements). Head (Fig. 18) enormously expanded in front and strongly receding behind; greatest head width across the outermost point of genae (mandibular acetabula), which clearly surpasses the head width across the eyes (the latter included). Antennal scape longer, i. e. nearly as long as head length (SI). Petiolar node (Fig. 28) much thicker in side-view, cuboid, with the apex very broadly rounded; in dorsal view the posterior surface of node appears flat yet not excavate.

Additional differences from ferox are as follows: Base of proximal mandibular spine with a small tooth; eyes slightly smaller, their maximum diameter distinctly less than one third of head length.

Additional differences from atrox: head length as measured between anteriormost point of stalked mandibular acetabula and occipital carina exceeding head length as measured between anteriormost point of frontal lobes and occipital carina; significantly greater cephalic and mandibular indices; semicircular rugulae between posterior end of frontal carinae and inner border of eyes at best vertigial.

Type Material
Kempf (1975) - BOLIVIA: Huachi, Beni, September 1921, W. M. Mann leg. 1 female (holotype, type no. 56821); another worker in the USNM collection bears the same locality, date and collector indications but no type label, this being probably a nidotype inasmuch as Weber had seen only the holotype which I have examined.