''Malagidris'' is a Malagasy

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

s in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Myrmicinae Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...

. Described in 2014, the genus contains six

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

Species

* '' Malagidris alperti'' Bolton & Fisher, 2014 * '' Malagidris belti'' (Forel, 1895) * '' Malagidris dulcis'' Bolton & Fisher, 2014 * '' Malagidris galokoa'' Bolton & Fisher, 2014 * '' Malagidris jugum'' Bolton & Fisher, 2014 * '' Malagidris sofina'' Bolton & Fisher, 2014

Taxonomy

The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of this genus, ''M. belti'' ( Forel, 1895), has had a moderately varied taxonomic history. It was originally described in the genus ''

Aphaenogaster ''Aphaenogaster'' is a genus of myrmicine ants. About 200 species have been described, including 18 fossil species. They occur worldwide except in South America south of Colombia, sub-Saharan Africa, and Antarctica. They are often confused w ...

'' (

Mayr Mayr is a German surname. Notable people with the surname include: * Andrea Mayr (born 1979), Austrian female long-distance runner * Ernst Mayr (1904–2005), German American evolutionary biologist * Georg Mayr (1564–1623), Bavarian Jesuit pri ...

, 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 The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. In hymenopterans of t ...

, 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 Congener may refer to: * A thing or person of the same kind as another, or of the same group. * Congener (biology), organisms within the same genus. * Congener (chemistry), related chemicals, e.g., elements in the same group of the periodic table. ...

with it. The final act of this history has been the realisation that ''Brunella'' (Forel, 1917) is the junior

homonym In linguistics, homonyms are words which are homographs (words that share the same spelling, regardless of pronunciation), or homophones (equivocal words, that share the same pronunciation, regardless of spelling), or both. Using this definition, ...

of a

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

genus ''Brunella'' (G.W. Smith, 1909), from

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. 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 In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

, 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 Haiti (; ht, Ayiti ; French: ), officially the Republic of Haiti (); ) and formerly known as Hayti, is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean Sea, east of Cuba and Jamaica, and ...

, 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.

References

* * *Emery, C. (1915). "Definizione del genere Aphaenogaster e partizione di esso in sottogeneri." ''Parapheidole e Novomessor nn. gg. Rendiconto delle Sessioni della R. Accademia delle Scienze dell'Istituto di Bologna'' (N.S.), 19: 67–75 * * {{Taxonbar, from=Q17107691 Myrmicinae Ant genera Hymenoptera of Africa Insects of Madagascar Endemic fauna of Madagascar