''Pachycondyla aberrans'' 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 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 ...

of formicid in the ant subfamily

Ponerinae Ponerinae is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including ''Dinoponera gigantea'' - one of the world's largest species of ant. Mated workers have replaced the queen as the fun ...

known from a single fossil found in Russia.

History and classification

''P. aberrans'' is known from a single ant found in Russia. The specimen was described from a

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason fo ...

preserved in

diatomite Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to le ...

deposits of the Bol’shaya Svetlovodnaya site. The site is exposed on the bank of Barachek Creek upstream from the creek's confluence with the Bol’shaya Svetlovodnaya River in the

Pozharsky District Pozharsky District (russian: Пожа́рский райо́н) is an administrativeLaw #161-KZ and municipalLaw #191-KZ district (raion), one of the twenty-two in Primorsky Krai, Russia. It is located in the northern and northwestern parts of t ...

, on the Pacific Coast of Russia. The fossil-bearing rocks preserve possibly

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of t ...

plants and animals which lived in and around a small lake near a volcano. The site has been attributed to either the Maksimovka or Salibez Formations and compared to the Bembridge Marls and

Florissant Formation The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and ...

, both of which are Priabonian in age. At the time of description, the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

adult specimen, number PIN 3429/104 was preserved in the A. A. Borissiak Paleontological Institute collections, part of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across t ...

. The fossil was first described by the trio of paleomyrmecologists Gennady Dlussky,

Alexandr Rasnitsyn Alexandr Pavlovich Rasnitsyn (Russian: Александр Павлович Расницын) is a Russian entomologist, expert in palaeoentomology, and Honored Scientist of the Russian Federation (2001). His scientific interests are centered on ...

and Ksenia Perfilieva. In the type description, Dlussky, Rasnitsyn and Perfilieva named the species ''P. aberrans'', with 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 ...

derived the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''aberrans'' meaning "aberrant" or "to deviate". ''P. aberrans'' is one of two ''Pachycondyla'' species that were described by Dlussky, Rasnitsyn and Perfilieva from Bol’shaya Svetlovodnaya, the other species '' P. oligocenica'' being described from a male.

Description

The incomplete adult of ''P. aberrans'' is missing its head and a portion of the gaster, making determination of its sex impossible, with male or a queen as possibilities. The preserved portions of the ant indicate a body length of , with a tall petiole node between the thorax and the gaster. The forewing is also incomplete, with an estimated length of approximately . The venation in the wings is reduced in development, with the rs-m cross vein not fully developed and enclosing the rm cell. The cell is present in forewing of ''P. oligocenica'', distinguishing the two species.

References

{{Taxonbar, from=Q27650756 Eocene insects Fossil ant taxa Fossil taxa described in 2015 Cenozoic insects of Asia †Pachycondyla aberrans Insects described in 2015