Thaumatomyrmex zeteki

Identification
Kempf (1975) - M. R. Smith, in the original description, compares zeteki with Thaumatomyrmex cochlearis on account of the scarcely rounded and subangulate propodeal profile. But the closest species are in the ferox-group, where it has already been differentiated from Thaumatomyrmex paludis. It differs from the remaining species in the same group by much smaller size, stouter antennae, short mandibles, scarcely broadened head, greater frontal width, shorter antennal scapes with segments II-VI of funiculi strikingly transverse, and relatively longer hind femora, the length of which is subequal to head width.

Key to Thaumatomyrmex

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

Nomenclature

 *  zeteki. Thaumatomyrmex zeteki Smith, M.R. 1944b: 98 (w.) PANAMA. Junior synonym of atrox: Longino, 1988: 38. Revived from synonymy: Fernández, 2008: 211 (in key); Jahyny, Lacau, et al. 2008: 335 (in key). See also: Kempf, 1975b: 116.

Worker
Kempf (1975): paratype - TL 3.3 mm; HL 0.69 (0.76) mm; HW 0.65 (0.76) mm; CI 94 (100) ; ML 0.60 (0.72) mm; MI 87 (94); IfW 0.44 (0.51); IfI 67 (68); SL 0.52 (0.60) mm; SI 75 (78); WL 1.05 (1.15) mm; PnW 0.45 (0.52) mm; HfL 0.63 (0.72); HfI 96 (95-100); PW 0.57 (0.64) mm. Black; mandibles, frontal lobes, antennae, legs except coxae, and tip of gaster light yellowish brown to ferruginous. Closest to Thaumatomyrmex paludis, exhibiting the following significant differences:

Mandibles with a minute but distinct basal denticle, the second spine longer than one half the length of the apical spine; distance between anteriormost point of genae respectively of the mandibular acetabulum) and anterior orbit of eye nearly as long as the maximum diameter of the latter which shows about 8-9 facets in a row across the eyes that are decidedly smaller than in paludis; antennal scape and funiculus stouter (Figs. 16, 37), the funicular segments II-VI strikingly transverse; antennal socket punctate-rugulose but not surrounded by semicircular rugae; metanotal groove and suture present, separating in profile the mesonotum from the propodeum,  the latter, likewise seen in profile, not continuously and evenly rounded, but nearly forming a blunt angle at their point of junction, yet not quite as marked as in cochlearis; inferior portion of lateral border of declivous face of propodeum with a distinct and sharp carinule, the lowermost seta of the pair flanking both sides arising from the top of this carinule; propodeal spiracle placed higher up on sides of thorax, somewhat prominent on a low but distinctly raised cone, quite visible in dorsal view; fore femora with a row of oblique hairs on flexor face, a unique feature in the genus; anterior and dorsal surface of tergum I of gaster forming a subacute angle when seen in profile; values for interfrontal, scape and hind femur indices lower than in paludis, under which further differences are cited.

Type Material
Kempf (1975) - PANAMA, Canal. Zone: Barro Colorado Island, July-August 1942, James Zetek leg. 2 females (holotype and paratype, Coll. Zetek no. 4975, Lot No. 42-11986, USNM type no. 56483); paratype worker examined.