''Aphaenogaster avita'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

species of ant in the subfamily

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 ...

known from a solitary

early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

fossil found in

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. At the time of description ''A. praerelicta'' was one of twelve '' Aphaenogaster'' species to have been described from fossils and the only fossil species from Japan.

History and classification

''Aphaenogaster avita'' is known from a solitary fossil insect which is a compression-impression fossil preserved in a layer of soft diatomite. Along with several other insect fossils, the ''A. avita'' specimen was collected in 1969 from layers of the early to middle Miocene Chojabaru Formation. The formation is composed of diatomites, sandstones and mudstones with the insects recovered from the upper and middle sections. The formation outcrops in a small area on Cape Chojabaru on the eastern side of Iki Island, and the flora of the formation is notably similar to that of Daijima flora, which is noted to be Middle Miocene in age. The fossil ant was first studied by paleoentomologist Ienori Fujiyama of the

National Museum of Nature and Science The is in the northeast corner of Ueno Park in Tokyo. The museum has exhibitions on pre-Meiji period, Meiji science in Japan. It is the venue of the taxidermied bodies of the legendary dogs Hachikō and Taro and Jiro. A life-size blue whale mode ...

in Tokyo. Fujiyama's 1970

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have ...

of the new species was published in the Japanese journal ''Memoirs of the Natural Science Museum, Tokyo''. The etymology for the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''avita'' was not given with the type description. When first described the species was placed by Fujiyama into the ''Aphaenogaster'' subgenus "''Deromyrma''", however in the time since the type description, "''Deromyrma''" has been subsumed into ''Aphaenogaster'' as a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

and is no longer in use.

Description

The ''Aphaenogaster avita'' specimen is a partially preserved queen caste adult which was fossilized with its underside facing upwards and the body turned slightly sideways. The specimen has wings attached, a poorly preserved head and is missing its abdomen, making gender determination hard. The head has an estimated length of and the thorax is estimated at with distinct longitudinal striations on it. The preserved forewing is long and has a maximum width of . The wing venation shows a narrow costal cell and a thin stigma. The wing shows a reduced cubital vein, with a notable bend, and forming an elongated cubital cell with the median vein.

References

{{Taxonbar, from=Q14445659 avita Miocene insects Fossil ant taxa Ants of Japan Fossils of Japan Fossil taxa described in 1970