''Aphaenogaster dlusskyana'' 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 single Middle Eocene fossil found in amber on Sakhalin. At the time of description ''A. dlusskyana'' was one of eight ant species known from Sakhalin fossil.

History and classification

''A. dlusskyana'' is known from a single adult female fossil, the holotype, specimen number "PIN3387-172" which, at the time of the genus description, was residing in the Paleontological Institute, Russian Academy of Sciences, in Moscow. The described specimen is a worker caste adult preserved as an inclusion in a transparent chunk of

Sakhalin amber Sakhalin ( rus, Сахали́н, r=Sakhalín, p=səxɐˈlʲin; ja, 樺太 ''Karafuto''; zh, c=, p=Kùyèdǎo, s=库页岛, t=庫頁島; Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ, ''Sahaliyan''; Orok: Бугата на̄, ''Bugata nā''; Nivkh: ...

. The amber specimen was recovered from deposits on

Sakhalin island Sakhalin ( rus, Сахали́н, r=Sakhalín, p=səxɐˈlʲin; ja, 樺太 ''Karafuto''; zh, c=, p=Kùyèdǎo, s=库页岛, t=庫頁島; Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ, ''Sahaliyan''; Orok: Бугата на̄, ''Bugata nā''; Nivkh: ...

, in far eastern Russia during a 1972 collecting expedition. The expedition recovered amber from the beaches of the Okhotsk Sea at the mouth of the

Naiba River The Cerna ( hu, Cserna) is a river in Romania, a left tributary of the river Danube. The Cerna has its source on the south-east side of the Godeanu Mountains and flows into the Danube near the town Orșova. Sakhalin amber has been attributed a range of geological ages, with

Vladimir Zherikhin Vladimir Vasilevich Zherikhin (russian: Владимир Васильевич Жерихин, 22 July 194521 December 2001), of the Paleontological Institute, Russian Academy of Sciences, Moscow, was one of the world's leading paleoentomologists ...

in 1978 suggesting dates between 59 and 47 million years old. In 1988,

Gennady Dlussky Gennady ( rus, Геннадий, p=ɡʲɪˈnadʲɪj), also spelled Gennadi or Gennadiy, is a Russian male name. They are derived from the Greek given name Gennadius. People *Gennady Gladkov, Soviet and Russian composer *Gennady Golovkin, Kazakh bo ...

suggested a tentative Paleocene age, which was followed by subsequent authors through 2013. Research published in 1999 on the Naibuchi Formation, in which Sakhalin amber is directly preserved, however, gives a Middle Eocene age based on geological and paleobotanical context. The Sakhalin amber forest had a variety of plants living in a mixed coastal swamp, river, and lake environment. The river and lake system had numerous swampy areas that resulted in active peat bog formation. The bogs were surrounded by '' Osmunda'', Nymphaeaceae and Ericaceae plants, while '' Taxodium'', '' Alnus'', '' Salix'', and other trees populated the forest. The amber fossil specimen was first studied by paleoentomologists A. G. Radchenko and E. E. Perkovsky of the National Academy of Sciences of Ukraine, with their 2016

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 ...

for the species being published in the ''Paleontological Journal''. The species name was coined as a

patronym A patronymic, or patronym, is a component of a personal name based on the given name of one's father, grandfather (avonymic), or an earlier male ancestor. Patronymics are still in use, including mandatory use, in many countries worldwide, alt ...

honoring the Russian paleoentomologist and myrmecologist

, who had died in 2014. Radchenko and Perkovsky suggested in the description that ''A. dlusskyana'' was the oldest described Myrmicinae species belonging to a living genus of the subfamily. They noted older fossils are reported in the literature, but no detailed descriptions of the specimens have been published. Aphaenogaster dlusskyana PIN3387-172 head

Aphaenogaster dlusskyana PIN3387-172 head

Aphaenogaster amphioceanica SMNSDO4629 01

''A. dlusskyana'' has a pair of distinctive long spines near the rear of her propodeum that are not seen in any of the late Eocene European amber species, or in any Upper Eocene United States amber species. Workers of two amber species, ''

Aphaenogaster amphioceanica ''Aphaenogaster amphioceanica'' is an extinct species of ant in the subfamily Myrmicinae known from a single possibly Miocene fossil found in amber on Hispaniola. At the time of description ''A. amphioceanica'' was one of two ''Aphaenogaster' ...

'' from Miocene Dominican amber and '' Aphaenogaster praerelicta'' from Late Oligocene to Early Miocene Mexican Amber have similar spines. ''A. dlusskyana'' is separated from ''A. praerelicta'' in the shape of the spines, which widen near the base in ''A. praerelicta'', in the more rounded petiole of the ''A. dlusskyana'', and overall size, with ''A. praerelicta'' workers being more than longer. ''A. amphioceanica'' has a very elongated head that does not have distinct rear corners, rather the rear margin forms a "collar" shape, features not seen in the ''A. dlusskyana'' worker.

Description

The single worker of ''A. dlusskyana'' has a long body and a long head. The body has a number of long hairs scattered on it, with a large amount present on the upper surface of the gaster, while the tarsi have a dense covering of hairs that lie almost flat and curl upward at the tips. There is coarse parallel ridging running the length of the mesosoma, and the gaster, waist, and head are smooth with no surface sculpturing. The head is rectangular in outline, being 1.3 times as long as wide and with very slightly convex sides. The rear margin of the head also is slightly convex and the rear corners are "narrowly" rounded. Two lobes are well developed toward the front of the head, and partly cover the bases of the antennae and antennal sockets. The antennae are composed of 12 segments, each of the segments being elongated, and the last four at the tip forming a club. At the base, the scape is elongated and one third of its length projects past the rear edge of the head. On each of the triangular shaped mandibles, the inner chewing surface is 80 percent as long as the whole mandible length.

References

{{Taxonbar, from=Q28667206 dlusskyana Eocene insects Fossil taxa described in 2016 Hymenoptera of Asia Sakhalin amber Prehistoric insects of Asia Fossil ant taxa