Malagidris
Malagidris is a Malagasy genus of ants in the subfamily Myrmicinae. Described in 2014, the genus contains six species. Taxonomy. The type species of this genus, "M. belti" (Forel, 1895), has had a moderately varied taxonomic history. It was originally described in the genus "Aphaenogaster" (Mayr, 1853), even though Forel remarked on its 3-segmented antennal club, rather than 4 as is usual in that genus. This character, coupled with the presence of angulate humeri and a queen with a depressed mesosoma, caused Emery (1915) to exclude "M. belti" from "Aphaenogaster" and transfer it to "Atopula" (Emery, 1912). Forel  (1917) decided that "Atopula" was artificial, "composed of disparate species," and established the genus "Brunella" to include only "M. belti". The component species of "Atopula" were later dispersed to other genera by Bolton (1976), who retained genus "Brunella" as its "affinities are unclear." Later however, Bolton (1982) synonymised "Brunella" under "Aphaenogaster", thus returning "M. belti" to its original generic combination. More extensive recent sampling of the Madagascan ant fauna has made it clear that this synonymy was incorrect. The discovery of several species referable to Forel's "Brunella" has allowed the diagnosis of a distinct group of Madagascan endemics, which  are convergent in some characters with "Aphaenogaster" but certainly not congeneric with it. The final act of this history has been the realisation that "Brunella" (Forel, 1917) is the junior homonym of a crustacean genus "Brunella" (G.W. Smith, 1909), from Tasmania. No replacement name was essential for "Brunella" (Forel, 1917) while it was a junior synonym, but after it was revived from synonymy a replacement name was necessary: "Malagidris". Identification. The larger, more gracile species (e.g. "M. alperti", "M. galokoa", "M. jugum", "M. sofina") of "Malagidris" are remarkably convergent on the widely distributed genus "Aphaenogaster". However, all species of "Malagidris  have two critical features never exhibited by Aphaenogaster" species. First, the midpoint of the anterior clypeal margin of "Malagidris" has a single, stout, unpaired seta. In "Aphaenogaster" there is always a conspicuous pair of setae, one on each side of the midpoint of the anterior clypeal margin. Second, "Aphaenogaster" species do not have the characteristic structure of the anteroventral peduncle of the petiole. In addition to these, "Malagidris" always has the following: a transverse crest present on the stipes of the maxilla; a 3-segmented antennal club; a subpetiolar process present; a strongly developed sting; the anterior clypeal margin convex  at the midpoint. In "Aphaenogaster", by contrast, the stipes usually lacks a crest (a crest is incompletely and weaky developed in a few species, strong only in "A. relicta", from Haiti, which may not be properly referable to "Aphaenogaster"), usually has a 4-segmented antennal club (5-segmented to gradually incrassate in some species but never 3-segmented), lacks a subpetiolar process, has a very weakly developed or vestigial sting, and usually (but not always) has the midpoint of the anterior clypeal margin concave or indented.