Tetramorium obtusidens Viehmeyer

Bolton, B., 1979, The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Malagasy region and in the New World., Bulletin of the British Museum (Natural History) Entomology 38, pp. 129-181 : 178

Tetramorium obtusidens Viehmeyer

Following the removal of adelphon and kydelphon from the series formerly associated with obtusidens it is necessary to make a few adjustments to the description of this species.

Worker. TL 2.4 - 2.7, HL 0.58 - 0.64, HW 0.49 - 0.54, CI 81 - 85, SL 0.38 - 0.42, SI 77 - 80, PW 0.34 - 0.38, AL 0.68 - 0.74 (8 measured).

With the general characters of the complex and of the bicarinatum-group to which it belongs, but with additional characters as follows. Frontal carinae less strongly developed than in adelphon or kydelphon , extending back beyond level of eye but weak, scarcely stronger than other cephalic rugulae. Maximum diameter of eye 0.12 - 0.14, about 0.25 - 0.27 x HW. Petiole node in dorsal view as broad or slightly broader than long. Dorsum of head irregularly longitudinally rugulose, with a reticulum occipitally. Dorsal alitrunk reticulate-rugulose but without a raised transverse carina at the promesonotal junction. Petiole dorsum with sparse rugulae, postpetiole dorsally with fine superficial punctulation, at most with only one or two very feeble longitudinal marks. Pilosity on dorsal surfaces of head and body much denser than in adelphon or kydelphon , the individual hairs finer and more flexuous than in those species. Colour pale yellow.

With the removal of adelphon and kydelphon , obtusidens is known only from Singapore. To the present it is the smallest known member of the bicarinatum-group.