Ectatomminae

The subfamily Ectatomminae is represented in Australia by two genera, Gnamptogenys and Rhytidoponera. Gnamtpogenys is uncommon and restricted to Cape York Peninsula, Queensland while Rhytidoponera is one of the most common groups of ants in Australia. Nests of Gnamptogenys are in rotten wood while Rhytidoponera species are generally soil nesting.

Genus richness
Genus richness by country based on regional taxon lists (countries with darker colours are more genus-rich).



Species richness
Species richness by country based on regional taxon lists (countries with darker colours are more species-rich).



Nomenclature
ECTATOMMINAE [subfamily of Formicidae]
 * Ectatommii Emery, 1895j: 767 [as tribe of Ponerinae]. Type-genus: Ectatomma.
 * Ectatomminae: Bolton, 2003: 45, 172 [as subfamily of Formicidae].

Bolton 2003:

Diagnosis With characters of poneromorph subfamilies. Clypeus broadly inserted between frontal lobes; anterior clypeal margin with a narrow lamellar apron (note 1). Outer margins of frontal lobes not pinched in posteriorly. Torulus not completely fused to frontal lobe. Promesonotal suture fully mobile to fully fused. Metapleural gland orifice in profile a longitudinal to oblique curved slit or narrow crescent, bounded below by a convex rim of cuticle that directs the orifice dorsally to posterodorsally (note 2). Metacoxal cavities open, either fully open or with endpoints of annulus acute and almost touching. Mesotibia and metatibia each with 0 - 1 spur (1 - 2 in males). Pretarsal claws with a preapical tooth (note 3). Petiole with or without tergosternal fusion (note 4); laterotergites indistinct to absent. Helcium projects from about the midheight of the anterior face of abdominal segment III; no high vertical anterior face to abdominal segment III above the helcium. Stridulitrum absent or present on pretergite of abdominal segment IV (note 5). Antenna with 12 segments (13 in male). [Synopsis, p. 172.]

Notes (1) Also present in Heteroponerini and may be a synapomorphy of the two groups; the feature is also encountered among several groups of Myrmicinae. (2) Cuticle below the slit-like gland orifice often bears dorsally directed guard-hairs. The structure of the orifice appears identical to that seen in basal Myrmicinae and may be a synapomorphy of the two groups. (3) In Ectatomma, Rhytidoponera and almost all Gnamptogenys species the preapical tooth on the inner margin of each pretarsal claw is conspicuous. In a very few mainly minute, cryptic Gnamptogenys species the extra tooth is small, basal and inconspicuous; in a couple of Gnamptogenys species and in all Typhlomyrmex species it appears to be restricted to the foreleg claws alone. Preapical tooth is present on the pretarsal claws in males of all genera. (4) The petiole shows tergosternal fusion in Ectatomma, Gnamptogenys and Typhlomyrmex. In Rhytidoponera the tergite and sternite are tightly attached but are not fused. (5) A stridulitrum is entirely absent in Typhlomyrmex and Gnamptogenys but is present on the pretergite of abdominal segment IV in Ectatomma. In Rhytidoponera it is present either on the pretergite or on the presternite of abdominal segment IV. In the entire Formicidae the presence of a stridulitrum on sternite IV is known only here and in Nothomyrmecia, which certainly represents a parallelism.

Comments (i) Ectatomminae is dimorphic as regards the jugal lobe of the hindwing. It is present in alates of Ectatomma but absent in those of Rhytidoponera, Gnamptogenys and Typhlomyrmex. (ii) According to Hashimoto (1996) Ectatommini and Myrmicinae share the development of a cuticular lobe mid-anterodorsally on the pretergite of abdominal segment III, which is absent in all other ants. If universal this would constitute a powerful synapomorphy for the two groups. However, his sample size is small and lacks some critical components (for example Heteroponerini, Paraponerini, Typhlomyrmecini); a much wider survey is required.