Megalomyrmex timbira

The type material consisted of two foragers collected from the ground in tropical forest.

Identification
Brandão (1990) - M. timbira can be distinguished from all other species of the Leoninus group by the shape of propodeum, in lateral view.

Brandão (2003) - To distinguish M. timbira from Megalomyrmex staudingeri, as they seem to occur sympatrically at the Colombian- Venezuelan border, I used not only the peculiar propodeal shape in M. timbira, but also the fact that in M. timbira the petiole is almost twice as wide as the postpetiole, while in M. staudingeri, they are of similar width. The shape of the postpetiole is similar to that depicted in figure 83 in Brandão (1990), while the dorsal profile of the postpetiole is always evenly rounded.

Distribution based on Regional Taxon Lists
Neotropical Region: Ecuador, Venezuela.

Nomenclature

 *  timbira. Megalomyrmex timbira Brandão, 1990: 439, figs. 45, 49 (w.) VENEZUELA.

Worker
Mandible smooth; anterior clypeal border straight without median denticle; 3-segmented antennal club: frontal suture impressed; 18 ocular facets at compound eyes largest diameter; promesonotal suture impressed dorsally; dorsal face and declivity of propodeum meeting, in side view, in a 120° angle, forming nonsharp teeth in lateral view; declivity smooth and non-depressed longitudinally: mesosternum and metasternum without acrotergites: epipetiolar carina complete: non-pedunculate petiole with anteroventral denticle: dorsal margin of petiolar node, in side view. concave; dorsal margin of petiolar node, in frontal view, subquadrate; ventral face of postpetiole without process; apex of femura acuminate.

Color: dark reddish-brown, almost black.

Brandão (2003) - To the original description, I should add that the epipetiolar carina in M. timbira is complete around the foramen, although in some specimens the carina almost fades out at the mid propodeal declivitous face. Some specimens are distinctly more hairy in relation to the type specimens and to other Megalomyrmex species in the Leoninus group.

Type Material
La Flautera, ca. Palmira. Tachira, Venezuela, 1200m (07°51'N, 72°13'W). Holotype and paratype at Museu de Zoologia da USP; paratype at Facultad de Agronomia de Maracay, Venezuela. The type workers have been collected by John Lattke, foraging isolated on the ground of a tropical forest in August 8, 1983.

Etymology
The word timbira means orphan in Tupi, referring to the lack of true queens in the Leoninus group.

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Brandão C. R. F. 1990. Systematic revision of the Neotropical ant genus Megalomyrmex Forel (Hymenoptera: Formicidae: Myrmicinae), with the description of thirteen new species. Arquivos de Zoologia (São Paulo) 31: 411-481
 * Brandão C. R. F. 2003. Further revisionary studies on the ant genus Megalomyrmex Forel (Hymenoptera: Formicidae). Papeis Avulsos de Zoologia (São Paulo) 43: 145-159
 * Fernández F., and E. E. Palacio. 1995. Hormigas de Colombia IV: nuevos registros de géneros y especies. Caldasia 17: 587-596.
 * Salinas P. J. 2010. Catalogue of the ants of the Táchira State, Venezuela, with notes on their biodiversity, biogeography and ecology (Hymenoptera: Formicidae: Amblyioponinae, Ponerinae, Proceratiinae, Myrmicinae, Ecitoninae, Formicinae, Pseudomyrmecinae, Dolichoderinae). Boletín de la SEA 47: 315-328.