''Pachycondyla eocenica'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species of

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

in the formicid subfamily

Ponerinae Ponerinae, the ponerine ants, 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 replac ...

described from fossils found in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. ''P. eocenica'' is one of six

Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...

Pachycondyla ''Pachycondyla'' is a Ponerinae, ponerine genus of ants found in the Neotropics. Distribution ''Pachycondyla'' is currently distributed from southern United States to northern Argentina, but some fossil species (e.g. ''Pachycondyla eocenica, P. ...

'' species.

History and classification

When described, ''Pachycondyla eocenica'' was known from two fossil insects which are compression-impression fossils preserved in layers of soft

sedimentary Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...

rock. Along with other well-preserved insect fossils, the ''P. eocenica'' specimens were collected from layers of the

Messel pit The Messel Formation is a Formation (geology), geologic formation in Hesse, central Germany, dating back to the Eocene Epoch (geology), epoch (about 47 Ma). Its geographic range is restricted to the Messel pit. There it unconformably overlie ...

World Heritage Site World Heritage Sites are landmarks and areas with legal protection under an treaty, international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural ...

. The formation is composed of brown coals, oil shales, and bituminous shale, which preserved numerous insects, fish, birds, reptiles, and terrestrial mammals as a notable lagerstätten. The area is a preserved maar lake which initially formed approximately 47 million years ago as the result of volcanic explosions. At the time of description, the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen, number SMF MeI 10999, was preserved in the Senckenberg Research Station Messel fossil collections. The fossils were described by Gennady Dlussky and Sonja Wedmann in a 2012 paper on the poneromorph ants of Messel. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

"eocenica" is derived from the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

age of the fossil. The species is one of six ''Pachycondyla'' species which have been described from Messel Formation fossils. All six of the species were described by Dlussky and Wedmann in the same 2012 paper, the other five being '' P. lutzi'', '' P.? messeliana'', '' P. parvula'', '' P. petiolosa'', and '' P. petrosa''. Another eight fossil species have been described from fossils in North America, Europe, and Asia.

Description

The ''Pachycondyla eocenica'' holotype specimen is a partially preserved adult

queen Queen most commonly refers to: * Queen regnant, a female monarch of a kingdom * Queen consort, the wife of a reigning king * Queen (band), a British rock band Queen or QUEEN may also refer to: Monarchy * Queen dowager, the widow of a king * Q ...

, which was fossilized as a lateral impression, missing portions of the legs and wings. The paratype is a very partial dorsal impression, preserving only the head, either of a gyne or a worker. The overall length of the queen is approximately and the head has an estimated length of . The antennae are slender in appearance, composed of a scape which extends nearly to the edge of the rear margin of the head. The

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

are rounded in outline and placed to the front of the midpoint on the head. The shape of the petiole scale is rounded on the top edge, as is that of both ''P. messeliana'' and ''P. succinea'', but it is larger than ''P. succinea'' and smaller than ''P. messeliana''.

References

External links

* {{Taxonbar, from=Q21027656 †Pachycondyla eocenica Fossil taxa described in 2012 Hymenoptera of Europe Fossil ant taxa Prehistoric life of Europe Lutetian insects Insects described in 2012