Ankylomyrma coronacantha Bolton

Bolton, B., 1981, A revision of six minor genera of Myrmicinae (Hymenoptera: Formicidae) in the Ethiopian zoogeographical region., Bulletin of the British Museum (Natural History) Entomology 43, pp. 245-307 : 248-249

Ankylomyrma coronacantha Bolton (Figs 1,2)

Ankylomyrma coronacantha Bolton , 1973 b: 235, figs 1 - 3. Holotype worker, Ghana: Eastern Region, Mt Atewa; by pyrethrum knockdown, sample A 4 / 3,12. vii. 1969 (D. Leston) (BMNH) [examined].

Worker. TL 6.3 - 6.8, HL 1.48 - 1.50, HW (at maximum in front of eyes) 1.38 - 1.42, CI 92 - 96, SL 1.06 - 1.12, SI 76 - 80, PW 1.20 - 1.22, AL 1.92 - 1.95 (4 measured).

Mandibles delicately and superficially longitudinally striate, with scattered fairly conspicuous pits. Palpi very long, the maxillary palps projecting beyond the posteroventral margin of the head when stretched out, their total length c. 1 - 60. Anterior clypeal margin with a median impression. Main features of head as given in generic diagnosis and Fig. 2. Eyes large, maximum diameter 0.36 - 0.38, about 0.27 - 0.28 x HW, situated at posterolateral corners of head. Frontal carinae irregular, running inside eyes to occipital margin. Scrobal area bounded below by a ridge which runs from the mandibular insertions to the extensive prominence at the occipital corner, below the eye. Occipital margin with a transverse raised broad lamella which projects into a number of teeth or spines, projecting especially strongly at the occipital corners. Promesonotum fused and swollen, the dorsum much higher than the propodeum in profile. Metanotal groove absent. Pronotum with three pairs of teeth or tubercles; dorsally with a pair of broad tubercles which are large and are seen to be blunt or truncated in anterior view; dorsolaterally, just anterior to pro-mesonotal junction, with a pair of broad acute, sometimes conical projections; humeral angles bluntly dentate, the teeth prominent in dorsal view. Mesonotum at point where sclerite begins to slope down to the propodeum with a pair of broad, acute teeth. Propodeal dorsum short, the entire dorsal face forming the base for a pair of long, stout spines. Apices of tibiae each terminating in a pair of cuticular tooth-like outgrowths. Petiole strongly bispinose, in profile the peduncle short and continuous with the dorsal surface of the node. Subpetiolar process a small tooth, anteriorly situated. First gastral tergite massive, developed into a subspherical ball which has an opening anteriorly, below the postpetiole. First sternite forms a narrow collar around the ventral portion of the orifice so that almost all of the visible gaster consists only of the first tergite. Sting strong and projecting anteriorly. Dorsum of head coarsely reticulate-rugose, the rugae strongly raised and enclosing broad foveo-late spaces. Ground-sculpture of fine shagreening or superficial punctulation. This sculpture also present on sides of head below the scrobes but the scrobal area itself merely densely reticulate-punctate. All pronotum and raised dorsum of mesonotum sculptured as dorsum of head but the pleurae, the sloping portion of the mesonotum and the propodeum with fine dense but superficial reticulation only. Petiole, postpetiole and first gastral tergite coarsely foveolate, the interspaces finely reticulate or reticulate-punctulate. Dorsum of head with numerous stout erect hairs which are also present, but sparser, on dorsum of promesonotum and dorsal portion of first gastral tergite; the hairs are denser and finer ventrally on the first tergite but do not occur on the sloping posterior half of the mesonotum, the propodeum or the petiole. Black with appendages lighter, orange-brown to red-brown.

This large and very spectacular ant is arboreal, but beyond that nothing is known of its biology.

Material examined Ghana: Mt Atewa (D. Leston). Cameroun: Korup (D. Jackson).