Ankylomyrma coronacantha
| Ankylomyrma coronacantha | ||||||||||||
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Ankylomyrma coronacantha Image: April Nobile, AntWeb |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Ankylomyrma | ||||||||||||
| Bolton , 1973 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Ankylomyrma coronacantha | ||||||||||||
| Bolton , 1973 |
Ankylomyrma coronacantha is a rare species of ant from Africa. As was only found out in 2014, it is one of only two living ( recent ) species of the ants subfamily Agroecomyrmecinae .
features
Workers of the species reach a length of 6.3 to 6.8 millimeters and have a peculiar, completely unmistakable morphology. They are mostly black in color. The mandibles , parts of the clypeus , antennae, tibia , tarsi and the first sternites of the gaster are orange to red-brown. The whole animal is massively sclerotized and armored.
On the top of the head is a sculpture made of ridges with rough pits between them. The back of the head is elongated into a transverse lamella that ends in a series of tooth-shaped protrusions. This “crown” was the godfather of the species name (from Latin corona : crown and Greek ἄκανθος ákanthos: thorn flower). The complex eyes are large, protrude from the contour of the head and sit far back on the back corners of the head. The twelve-link antennae do not carry a club, but the links become wider towards the tip. Your turn is covered up by wide frontal lobes . They can be put back in a shallow antenna pit, the upper edge of which is set off under the frontal lobes by a keel. The clypeus is greatly expanded, drawn forward and covers the mandibles when they are at rest. These have a chewing bar with five coarse teeth. Their surface is finely striped with clear point pits. The labial and maxillary palps are unusually long. On the trunk section ( Alitrunk or Mesosoma ) the promesonotum is swollen and has four pairs of triangular teeth. Two unusually long, pointed teeth also sit on the propodeum . Another tooth sits on top of the first stalk link ( petiolus ). From the free gaster adjoining behind the petiolus and the second stalk member ( postpetiolus ), the greatly enlarged first tergite can be seen almost exclusively . The sternite of this segment is only recognizable as a small, collar-shaped sclerite at the front edge, all other guest members are small and telescopically retracted into the first member. Inside the guest sits a prominent poison sting. The cuticle of Petiolus , Postpetiolus and Gaster also has very densely seated, coarse point pits. The cuticle bears very short, yellow, stiffly erect setae , longer ones almost only on the basal limbs.
The species was based on a worker described , the other stages are unknown.
Biology and way of life
The rare species has only been found twice so far. Statements on biology are therefore hardly possible. According to the findings, it is arboreal and probably predatory . Both finds come from tropical rainforests , one at 510 and the other at 640 meters above sea level.
distribution
The two previously known sites are in West Africa. The type locality is the Atewa Range in Ghana , the other site is the Korup National Park in Cameroon .
Phylogeny
After its discovery, the species was assigned to the subfamily Myrmicinae , but its exact location was considered unclear and puzzling. Surprisingly, a comprehensive molecular study of the Myrmicinae by Philip Ward and colleagues from the “Ant Tree of Life” research project, based on the comparison of homologous DNA sequences of eleven genes, showed that the species cannot belong to the Myrmicinae. The closest relative surprisingly turned out to be the South American "Armadillo Ant" Tatuidris tatusia . This makes Ankylomyrma the second living representative of the Agroecomyrmecinae, of which only fossil species are otherwise known. It is a basal, taxonomically isolated relic group that was once widely distributed, of which only these two species have survived to this day. In contrast to Ankylomyrma , Tatuidris is purely ground-living.
Individual evidence
- ↑ B. Bolton: A remarkable new arboreal ant genus (Hym. Formicidae) from West Africa . In: Entomologist's Monthly Magazine . Vol. 108, 1973, pp. 234–237 ( full text source , Internet Archive ).
- ↑ Barry Bolton: A revision of six minor genera of Myrmicinae (Hymenoptera: Formicidae) in the Ethiopian zoogeographical region . In: Bulletin of the British Museum (Natural History) / Entomology . tape 43 , no. 4 , 1981, p. 245–307 , urn : nbn: de: hebis: 30-1096284 .
- Jump up ↑ Philip S. Ward, Seán G. Brady, Brian L. Fisher, Ted R. Schultz: The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae) . In: Systematic Entomology . July 2014, p. n / a-n / a , doi : 10.1111 / syen.12090 .
