Cyphomyrmex bicornis

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Cyphomyrmex bicornis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cyphomyrmex
Species: C. bicornis
Binomial name
Cyphomyrmex bicornis
Forel, 1895

Cyphomyrmex bicornis casent0909373 p 1 high.jpg

Cyphomyrmex bicornis casent0909373 d 1 high.jpg

Specimen Labels

This species is known from two widely separated collection sites, one in southern Brazil, the other in Amazonian Colombia. The Colombian material was found in a 100mm deep soil sample in a primary forest (Castro et al., 2018).


See description section below.


Latitudinal Distribution Pattern

Latitudinal Range: -22.35° to -22.35°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), Colombia.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.


Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.




The queen and male are unknown.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • bicornis. Cyphomyrmex bicornis Forel, 1895j: 179 (w.) BRAZIL (Rio se Janeiro).
    • Type-material: syntype workers (number not stated).
    • Type-locality: Brazil: Rio de Janeiro, Colonia Alpina, nr Theresopolis (E.A. Göldi).
    • Type-depository: MHNG.
    • Status as species: Emery, 1924d: 341; Borgmeier, 1927c: 125; Weber, 1940a: 409 (in key); Kempf, 1966: 177 (redescription); Weber, 1966: 167; Kempf, 1972a: 92; Snelling, R.R. & Longino, 1992: 481 (in key); Bolton, 1995b: 167.
    • Distribution: Brazil.


Kempf (1966) - This rare and cryptic species, which so far has been collected only twice, is apparently confined to the woodlands in the Mantiqueira Mountains in Rio de Janeiro State. The specimen described above agrees well with the description of the type. Only the epinotum and postpetiolar dorsum are even smoother than in the type, lacking the vestigial tumuli mentioned by Forel. According to the original description, the mandibles are 5-6 toothed. My specimen has the tips of the mandibles broken off, but it seems that the basic dental number is five, there being a minute intercalary tooth in the diastema between the 2nd and 3rd tooth.

The present species is quite distinct, chiefly in the peculiarly auriculate occipital lobes of head, which occur only in Cyphomyrmex laevigatus. The latter, however, differs conspicuously from bicornis, from which it is differentiated clearly here.


Kempf 1966 Cyphomyrmex 1-13.jpg

Kempf (1966) - Total length 3.2 mm; head length 0.83 mm; head width 0.76 mm; thorax length 1.04 mm; hind femur length 0.83 mm. Brown; head and gaster somewhat darker. Integument densely granular, opaque, including the antennal scrobe.

Head (fig 5). Clypeus: anterior border feebly convex with a faint mesial notch, flanked on each side by a small tooth next to origin of frontal lobes. A median tumulus behind frontal area, flanked by a broad circular depression in the frontal lobes, above the antennal sockets. Carinae on vertex short but strong, diverging cephalad. Eyes with about 8 facets across greatest diameter. Preocular carinae curving mesad in front of eyes. Postocular carinae forming the strongly lamellate border the huge, auriculate, occipital lobes, continuing foreward and obliquely downward beneath the eyes, fading out just in front of the anterior orbit of eyes. Lower border of sides of head strongly but irregularly carinate. Scape rather thin at base, gradually thickening in a club-like fashion toward apex; its upper and lower border of leading face finely carinulate. Funicular segments II-VIII scarcely longer than broad.

Thorax (fig 23). Pronotum without dorsal projections, dorso-laterally marginate by a blunt and feeble longitudinal welt; antero-inferior corner subdentate and rectangular. Mesonotum: a pair of anterior, conical, bluntly tipped spines; a posterior pair of more approximate longitudinal welts, which are obtusely carinate, anteriorly diverging and rounded in profile. Mesoepinotal constriction strong. Epinotum completely unarmed and convex in both directions. Legs somewhat compressed, femora ventrally with a lamellate carinule. Hind femora ventrally dilated at basal third into an obtuse triangular lobe (fig 41).

Pedicel as shown in Figs. 23 and 33. Petiolar node broader than long, its anterior corners rounded in dorsal view, its dorsum without ridges, its postero-superior border without a projecting laminule. Postpetiole still broader than petiole, strikingly transverse, lacking conspicuous dorsal and lateral impressions and tumuli. Anterior border of tergum I of gaster carinulate above the postpetiolar insertion; laterally immarginate.

Hairs decumbent or appressed on body and appendages, rather fine and not scale-like, somewhat glistening, more conspicuous on scapes and legs.

Type Material

Kempf (1966) - Worker(s) collected by E. A. Goeldi, presumably deposited in the Forel collection; not seen.


References based on Global Ant Biodiversity Informatics

  • Lapola D. M., and H. G. Fowler. 2008. Questioning the implementation of habitat corridors: a case study in interior São Paulo using ants as bioindicators. Braz. J. Biol., 68(1): 11-20.