Microdaceton exornatum

Identification
The two similar species Microdaceton exornatum and Microdaceton tibialis can be separated as follows:

Distribution based on Regional Taxon Lists
Afrotropical Region: Kenya, Mozambique, South Africa, United Republic of Tanzania, Zambia, Zimbabwe.

Nomenclature

 *  exornatum. Microdaceton exornatum Santschi, 1913g: 478 (w.) SOUTH AFRICA. [Also described as new by Santschi, 1914e: 33.] Arnold, 1948: 225 (q.). Senior synonym of laevior, leakeyi: Bolton, 1983: 402. See also: Bolton, 2000: 28.
 * leakeyi. Microdaceton leakeyi Patrizi, 1947: 219, figs. 1, 2 (q.) KENYA. Bernard, 1953b: 253 (w.). Junior synonym of exornatum: Bolton, 1983: 402.
 * laevior. Microdaceton exornatum var. laevior Arnold, 1948: 225 (w.q.) SOUTH AFRICA. Junior synonym of exornatum: Bolton, 1983: 402.

Worker
Bolton (1983) - TL 3.0-4.0, HL 0.79-1.00, HW 0.76-0.94, CI 92-96, ML 0.48-0.58, MI 55-61, SL 0.50-0.64, SI 66-70, PW 0.40-0.50, AL 0.70-0.90 (10 measured).

Mandibles elongate and linear, without preapical armament but armed apically with a fork of 3 long spiniform teeth set in a more or less vertical series, the apical fork teeth without intercalary denticles. Anterior clypeal margin with a small median notch or indentation. Eyes large and conspicuous, clearly visible in full-face view. Antennal scrobes absent, frontal carinae absent, the antennal fossa ventrally on each side with a small laterally projecting tubercle in front of the eye. Occipital lobes with 2 pairs of tubercles which are variable in size, the first pair laterodorsal, the second pair at the posteriormost point of the lobes. Clypeus coarsely punctate to narrowly foveolate, with appressed to slightly elevated fine simple ground-pilosity, without standing or specialized hairs of any description. Dorsum of head foveolate, with a fine short simple hair arising from the centre of each foveola, the hairs appressed or nearly so, the head without specialized or standing pilosity. In profile the dorsal surface of the head rising and shallowly convex from the posterior clypeal margin to about the midlength, then suddenly depressed. Sides of head foveolate as dorsum. Dorsal outline of alitrunk dominated by the strong subconical mesonotal teeth or tubercles and the long propodeal spines, the latter without or only with a vestige of an infradental lamella. Metapleural lobes long and broad, slightly upcurved. Sides of alitrunk foveolate but on the mesopleuron the sculpture may be partially or almost wholly effaced. Dorsal surfaces of pronotum and mesonotum strongly foveolate, the metanotal groove with short longitudinal cross-ribs. Propodeal dorsum reticulate-punctate, sometimes with one or two laterally situated partial foveolae. Alitrunk without specialized or bizarre pilosity, only with fine short simple hairs arising from the foveolar centres. Usually these hairs are very short inconspicuous and appressed, but in some they may be longer and slightly elevated. Petiole in profile without spongiform or alar appendages, armed dorsally with a pair of spines and posterodorsally with a sharp triangular elevation. Postpetiole without spongiform tissue but with strong lateral alar prominences which appear in profile as thick longitudinal crests. In dorsal view the postpetiole very broad, spanning almost all of the basal width of the first gastral tergite. Basigastral costulae present, usually fine dense and distinctive, only rarely reduced in intensity. Petiole and postpetiole densely reticulate-punctate to granular. Petiole, postpetiole and first gastral tergite without standing hairs of any description, only with minute appressed sparse pubescence. Colour yellow, the appendages paler than the body.

Type Material
Holotype worker, SOUTH AFRICA: Natal Zululand (I. Triigardh) (not in NMB; presumed lost).

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1917. A monograph of the Formicidae of South Africa. Part III. Myrmicinae. Annals of the South African Museum. 14: 271-402.
 * Arnold G. 1948. New species of African Hymenoptera. No. 8. Occasional Papers of the National Museum of Southern Rhodesia 2: 213-250.
 * Bernard F. 1953. La réserve naturelle intégrale du Mt Nimba. XI. Hyménoptères Formicidae. Mémoires de l'Institut Français d'Afrique Noire 19: 165-270.
 * Bolton B. 1983. The Afrotropical dacetine ants (Formicidae). Bulletin of the British Museum (Natural History). Entomology 46: 267-416.
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Garcia F.H., Wiesel E. and Fischer G. 2013.The Ants of Kenya (Hymenoptera: Formicidae)Faunal Overview, First Species Checklist, Bibliography, Accounts for All Genera, and Discussion on Taxonomy and Zoogeography. Journal of East African Natural History, 101(2): 127-222
 * IZIKO South Africa Museum Collection
 * Lévieux J. 1972. Les fourmis de la savane de Lamto (Côte d'Ivoire): éléments de taxonomie. Bulletin de l'Institut Fondamental d'Afrique Noire. Série A. Sciences Naturelles 34: 611-654.
 * Santschi F. 1914. Meddelanden från Göteborgs Musei Zoologiska Afdelning. 3. Fourmis du Natal et du Zoulouland récoltées par le Dr. I. Trägårdh. Göteborgs Kungliga Vetenskaps och Vitterhets Samhälles Handlingar. 15: 1-44.