Thaumatomyrmex cochlearis

Kempf (1975) - The trivial name of the species suggests and records the fact that the holotype, was found among empty shells of land snails from an area in which the ground was literally carpeted with these shells. Creighton admits that the occurrence of the single worker among the shells was entirely fortuitous, but leaves the suggestion that the species might be a snail eater, finding similarity between the mandibles of Thaumatomyrmex workers and those of the snail-eating Carabid beetle Cychrus. Actually we know nothing about its habits.

Identification
Kempf (1975) - The description (see below) already differentiates the present species from Thaumatomyrmex mutilatus and Thaumatomyrmex contumax. The differences from the remaining species in the genus consist in the peculiar sculpture of the integument of the body, especially of head, the more abundant pilosity, the bulky petiolar node which presents in side-view the anterior surfaces subparallel and the apex very broadly rounded, a condition approximately obtained only in Thaumatomyrmex manni. This is it very distinctive species in its own right, with no peculiarly close affinities to any other of the known forms.

Distribution based on Regional Taxon Lists
Neotropical Region: Cuba, Greater Antilles.

Nomenclature

 *  cochlearis. Thaumatomyrmex cochlearis Creighton, 1928: 163, fig. 1 (w.) CUBA. See also: Kempf, 1975b: 110; Baroni Urbani & De Andrade, 2003a: 267.

Worker
Kempf (1975): TL 4.0 mm; HL 0.77 mm; HW 0.83 mm; CI 107; ML 0.73 mm; MI 95; IfW 0.52 mm; IfI 63; SL 0.57 mm; SI 74; WL 1.16 mm; PnW 0.56 mm; HfL 0.75 mm; HfI 90; PW 0.61 mm. Black; mandibles, frontal lobes, antennae and legs, except the black fore coxae, yellowish brown to ferruginous; exposed portion of terga III-V of gaster likewise brown. Head dorsally sculptured, the gular face smooth and shining; the dorsal sculpture is as follows: clypeus and frontal area finely longitudinally striate; remainder of cephalic dorsum striato-rugose, the rugae and striae diverging caudad, with coarse interspersed punctures, the median stripe on frons and vertex with the sculpture obsolescent and somewhat smooth and quite shining. Mandibles finely striate dorsally on base until origin of apical spine, the rest smooth and shining. Antennal scape and tibiae, also the tarsomeres, finely reticulate-punctate, not quite smooth nor noticeably shining. Thorax basically smooth and shining but with the same coarse punctures as on head, which here are somewhat sparser, especially on dorsum of promesonotum, denser on propodeum and sides, the latter also with patches of horizontal rugulae on posterior half; declivous face of propodeum with vestigial transverse rugae on upper half; mesopleura nearly entirely smooth and shining, except for a row of punctures along posterior border. Coxae and femora indistinctly sculptured, nearly smooth and quite shining. Petiole densely but more, finely punctured, the punctures sparser on anterior surface and dorsal face of node, the interstices smooth and shining. Gaster with the punctures still sparser and less conspicuous, especially on dorsum of tergum I and II which are quite smooth and shining. Remaining terga and sterna superficially punctulate to reticulate, quite shining. Hairs brownish yellow, pointed at apex, curved to suberect, much more abundant than in the other species, their distribution indicated in Figs. 14 and 23; note the presence of oblique projecting hairs on sides of head behind eyes and the three hairs on each side of declivous face of propodeum. Hairs on scapes and legs appressed.

Head in full-face view similar to that of Thaumatomyrmex mutilatus, i. e. nearly as long as broad, but somewhat more broadened in front, and its greatest length is between two parallels drawn through the anterior most point of the somewhat stalked mandibular acetabula of head and the posteriormost point of occipital carinule which is visible in full-face view. Mandibles (Fig. 29) lacking a tooth at base of proximal spine; this and the intermediate spines relatively longer, the intermediate spine longer than half the chord length of apical spine; the latter measures twice the distance between the mandibular insertion and the point of its own origin and is relatively longer than in mutilatus but does not project beyond the sides of head in front of eyes when the mandibles are closed. Frontal area vestigially delimited. Eyes comparatively smaller, their maximum diameter little longer than one fourth of head length, and bearing only 9-10 facets in a row across the same diameter. Also the interfrontal width is a bit narrower (cf. IfI which is 63 in this species as compared with 72-78 in mutilatus). Scapes likewise shorter, the scape index being only 74 (as compared with 81-89 in mutilatus). Clypeus without the pair of close-set setae on disc. Funicular segments II-VI distinctly broader than long.

Thorax without forming a bulge at pronotum, the dorsal outline of the latter continuous with the following mesonotum and basal face of propodeum; antero-inferior corner rounded. Metanotal suture vestigially discernible in dorsal view (very close to the promesonotal junction but does not break the dorsal profile. Propodeum with rather straight basal and declivous faces, both forming a distinct but narrowly rounded and obtuse angle at their junction; the latter marginate to vestigially carinulate on inferior half; the lowermost of the three setae projecting from lateral border arising from the top of this carinule. Petiole subtrapezoidal in dorsal view, broadest behind, yet not scalelike; as seen in profile, the little slanting anterior face is almost subparallel to posterior face, with the apex very broadly rounded; subpetiolar process well-developed anteriorly, posteriorly low and inconspicuous.

Type Material
Kempf (1975) - A lone worker (holotype) taken by W. J. Clench and W. S. Creighton at Mina Carlota (Cumanayagua) on November 2, 1927, in the Creighton collection, not seen. Dr. R. R. Snelling kindly sent me the requested information on the specimen, including the following measurements: HL 0.82 mm; median head length (from anterior clypeal border to occiput along sagittal line) 0.70 mm; HW 0.88 mm; ML 0.79 mm; IfW 0.54 mm SL 0.59 mm.

Additional References

 * [[Media:Creighton 1928b.pdf|Creighton, W. S. 1928b. A new species of Thaumatomyrmex from Cuba. Psyche (Camb.) 35: 162-166 PDF]]