''Odontomachus paleomyagra'' 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 known from a

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

fossil found in Europe.

History and classification

''O. paleomyagra'' is known from a single ant found in the Czech Republic.Wappler ''et al'' pg.495 The specimen was described from a compression fossil preserved in

lignite Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...

deposits of the Most Basin. The site is exposed in workings of the Bílina Mine, an opencast lignite mine in Bílina, Bohemia, Czech Republic. The mine exposes an approximately thick sequence of deposits recording the progression of a delta lake and bog ecosystem. Fossils of elevenKvacek ''et al'' pg.8 different insect orders are recorded in the Bílina site, representing members of 31 different insect families, with formicids being the most common insects, being nearly 40% of the specimens collected. Over the lifetime of the lake, the Bílina area was a delta region of a large drainage system emptying into a shallow lake, with expansive peat bogs surrounding it. There are several different fish and at least one frog from the genus ''

Rana Rana may refer to: Astronomy * Rana (crater), a crater on Mars * Delta Eridani or Rana, a star People, groups and titles * Rana (name), a given name and surname (including a list of people and characters with the name) * Rana (title), a histori ...

'' also known from the Bílina mine area that may have fed on the ants that fell into the lake. The low bog forest where ''O. paleomyagra'' lived had a mix of temperate plants such as alders, oaks and swamp cypress along with more tropical plants such as

climbing fern ''Lygodium'' (climbing fern) is a genus of about 40 species of ferns, native to tropical regions across the world, with a few temperate species in eastern Asia and eastern North America. It is the sole genus in the family Lygodiaceae in the Pter ...

, palmetto and

rattan Rattan, also spelled ratan, is the name for roughly 600 species of Old World climbing palms belonging to subfamily Calamoideae. The greatest diversity of rattan palm species and genera are in the closed-canopy old-growth tropical forests of ...

palms.

Odontomachus assiniensis casent0178262 head 1

The fossil was studied by a team of paleoentomologists led by Torsten Wappeler, with the group's 2014

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 be ...

of the new species being published in the journal ''Paläontologische Zeitschrift''. 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 ...

''paleomyagra'' is a combination of the Greek words for "ancient", "mouse", and "trap".Wappler ''et al'' pg.498 When first described, ''O. paleomyagra'' was one of three ''Odontomachus'' species that had been described from fossils, with both '' Odontomachus pseudobauri'' and '' Odontomachus spinifer'' being described in 1994 from fossils found in

Dominican amber Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree ''Hymenaea protera''. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil incl ...

. Both Dominican amber species are placed in the ''Odontomachus'' ''haematodus'' species group, which is neotropical in distribution. ''O. paleomyagra'' is distinct from ''haematodus'' group species in the less complex mandible dentition, and in the shape of the head.Wappler ''et al'' pg.499 The simpler mandibles of ''O. paleomyagra'' are closer to those of the

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

south-east African species ''

Odontomachus assiniensis ''Odontomachus assiniensis'' is a species of ponerinae ant known as a trap-jaw ant. The trap-jaw mechanism consists of mandibles which spring shut when triggered. This ant was first described in 1892 by the Italian entomologist Carlo Emery. T ...

'' and to the south-east Asian species group ''rixosus'', including ''

Odontomachus rixosus ''Odontomachus'' is a genus of ants commonly called trap-jaw ants found in the tropics and subtropics throughout the world. Overview Commonly known as trap-jaw ants, species in ''Odontomachus'' have a pair of large, straight mandibles capabl ...

'', ''

Odontomachus monticola ''Odontomachus'' is a genus of ants commonly called trap-jaw ants found in the tropics and subtropics throughout the world. Overview Commonly known as trap-jaw ants, species in ''Odontomachus'' have a pair of large, straight mandibles capabl ...

'', and '' Odontomachus latidens''. Unlike these species however, ''O. paleomyagra'' has a shorter more squared off head, rather than the elongated heads of the modern species.

Description

The ''O. paleomyagra'' queen is estimated to have been long in life, and the fossil has a total preserved length of . The head is nearly square in outline, being only 1.2 times longer than wide, with slightly bowed-in sides, rear corners which are rounded, and the rear edge which is concave. The front region of the head has distinct striations and the small oval eyes are placed notably close to the front edge of the head. There is little constriction of the head to the rear of the eyes, with the width across the eyes 1.06 time the width across the vertex of the head. In front of the clypeus, the bases of the long straight mandibles are placed close together. On the

masticatory Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...

margin there are no denticles, with possibly three teeth present at the tip end of each mandible, though only two are visible. The

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

is slightly elongated, with a mesoscutum that is a little wider than long and attaching with no overhang of the sclerites to the

propodeum The propodeum or propodium is the first abdominal segment in Apocrita Hymenoptera (wasps, bees and ants). It is fused with the thorax to form the mesosoma. It is a single large sclerite, not subdivided, and bears a pair of spiracles. It is strongl ...

. The petiole is rounded and narrow, without a spine on the upper surface.

Notes

References

* *

External links

{{Taxonbar, from=Q30589187 †Odontomachus paleomyagra Miocene insects Fossil taxa described in 2014 Prehistoric insects of Europe Fossil ant taxa Fossils of the Czech Republic Hymenoptera of Europe Taxa named by Michael S. Engel