Odontomachus are large ponerinae ants which are immediately recognised by the characteristic shape of the head and mandibles. They are most likely to be confused with species of Anochetus but differ in having the nuchal carina, which separates the dorsal from the posterior surfaces of the head, converging into a V at the midline. In the closely related Anochetus, the nuchal carina forms a broad, uninterrupted curve across the posterior dorsal extremity of the head.
They are generalist predators on small invertebrates, hunting singly and capturing prey with their elongate trap-like jaws. Patek et al. (2006) investigated the biomechanics of mandible strikes in O. bauri, which are used to capture prey, eject intruders, or jump to safety. Don´t miss the videos! More on the biology of Odontomachus can be found in the revision of Brown (1976).
Vertex smooth & shining; antennal scapes surpass posterior border of head in full face view; color redish-brown.
Males of Odontomachus are rarely collected and not easily matched with workers. During the FoCol project a male O. affinis from a type series deposited at the Museum für Naturkunde Berlin has been documented. Christiana Klingenberg kindly provided the image of this specimen: Male of O. affinis. Note the petiolar node of the male im comparison to the worker node.
Regarding this species, Brown (1976) states: "O. affinis is restricted to wet subtropical forests of SE Brazil (Espiritio Santo to Santa Catarina). In Sao Paulo state, at least, it occurs in and under rotten logs in plateau forest; I did not find it in the warmer lowland forest along the coast."
I have collected this species from leaf litter samples collected in the lowland forests of Cachoeira Nature reserve, though this species seems to be rare.
Disc of first gastric tergite very densely punctulate, opaque, longitudinally striae over a posterior portion of variable extent ; small species, light to dark brown in color.
A common species at Cachoeira Nature reserve. I have collected 17 specimens from a single soil sample. Therefore this Odontomachus, at least occasionally, seems to nest in soil.
Offline References for Odontomachus
Brown, W. L. (1976): Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section A. Introduction, subtribal characters. Genus Odontomachus. Studia Entomologica 19:67-171.