Megalomyrmex bidentatus

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Megalomyrmex bidentatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Megalomyrmex
Species group: leoninus
Species: M. bidentatus
Binomial name
Megalomyrmex bidentatus
Fernández & Baena, 1997

Megalomyrmex bidentatus casent0902332 p 1 high.jpg

Megalomyrmex bidentatus casent0902332 d 1 high.jpg

Specimen Labels

Brandão (2003) - This species was described based on workers collected by F. Escobar in two localities within the county of Barbacoa, Nariño province, Colombia (see localities description in Fernández and Baena, 1997): Tajadas, 1000 m (accession number 446), and Reserva Natural Río Nambí (see Escobar & Valderrama, 1995).

At a Glance • Ergatoid queen  


Photo Gallery

  • This large orange Megalomyrmex bidentatus is probably the largest Megalomyrmex of the Canandé, Ecuador. Megalomyrmex are known for their heavy chemical weaponry (alkaloids). The nest was located on a large tree trunk between some dead leaves. Photo by Phil Hoenle.


Brandão (2003) - The original description includes characters I used to define the Leoninus group, except for the bidentate propodeum, which is apparently the only apomorphy for this species. Megalomyrmex foreli and Megalomyrmex timbira may have pointed propodeal angles, but never produced as pointed teeth as in the M. bidentatus paratype examined. To the original description I should add that the paratype lacks paired pointed acrosternites at the meso and metasternae. Also Fernández & Baena (op. cit.) rightly call attention to the shape of the head is greatly modified in relation to other species in this group, being much longer than broad.

The only species in the Leoninus group recorded thus far in such high Andean altitudes is M. foreli, which can be distinguished from M. bidentatus by the presence of a conspicuous sharp tooth on the ventral side of the postpetiole, that may be worn out (if so leaving a noticeable scar), but never completely lacking as in M. bidentatus.


Latitudinal Distribution Pattern

Latitudinal Range: 1.283333333° to -1.683055556°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Colombia (type locality), Ecuador.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb




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

  • bidentatus. Megalomyrmex bidentatus Fernández & Baena, 1997: 112, fig. 3 (w.) COLOMBIA.
    • Type-material: holotype worker, 14 paratype workers.
    • Type-locality: holotype Colombia: Nariño, Barbacoas, Tajadas, no. 446 (F. Escobar); paratypes: 1 worker with same data, 13 workers Nariño, Barbacoas, Reserve Nacional Natural Rio Nambi, no. 190 (F. Escobar).
    • Type-depositories: ICNB (holotype); AMNH, BMNH, IAVH, IMLT, MIZA, MZSP, PSWC, USNM, UVCC, WEMC (paratypes).
    • Status as species: Brandão, 2003: 151; Fernández & Serna, 2019: 806.
    • Distribution: Colombia.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.


Type Material

Brandão (2003) - Fernández deposited one specimen labelled as paratype from Rio Nambí at the MZSP, but in the original description, after giving information on the holotype, the authors say: “Obrera paratipo: Una obrera con los mismos datos del holotipo depositada en MZSPC; 13 obreras...”, although in the measurements section they present figures taken from 13 “paratype” workers. I consulted Fernández, who agreed that their intention was to consider all 14 known specimens as types, so, with their agreement, I hereby correct this information, and thus consider also the specimens from the second locality as paratypes.


References based on Global Ant Biodiversity Informatics

  • 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