''Odontomachus pseudobauri'' 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 ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

in the 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 one possibly

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 on

Hispaniola Hispaniola (, also ; es, La Española; Latin and french: Hispaniola; ht, Ispayola; tnq, Ayiti or Quisqueya) is an island in the Caribbean that is part of the Greater Antilles. Hispaniola is the most populous island in the West Indies, and th ...

. ''O. pseudobauri'' is one of two species in the ant genus ''

Odontomachus ''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 capable ...

'' to have been described 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 ...

and is one of a number of ''Odontomachus'' species found in the

Greater Antilles The Greater Antilles ( es, Grandes Antillas or Antillas Mayores; french: Grandes Antilles; ht, Gwo Zantiy; jam, Grieta hAntiliiz) is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, Jamaica, and ...

History and classification

''Odontomachus pseudobauri'' is known from a solitary fossil insect which, along with a

coleoptera Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

n and a

diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

n, is an

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, aims to create an environment that supports equal opportunity for individuals and groups that form a society. ** Inclusion (disability rights), promotion of people with disabiliti ...

in a transparent yellow chunk of

purchased from an amber dealer in

Basel , french: link=no, Bâlois(e), it, Basilese , neighboring_municipalities= Allschwil (BL), Hégenheim (FR-68), Binningen (BL), Birsfelden (BL), Bottmingen (BL), Huningue (FR-68), Münchenstein (BL), Muttenz (BL), Reinach (BL), Riehen (BS ...

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. The amber was produced by the extinct ''

Hymenaea protera ''Hymenaea protera'' is an extinct prehistoric leguminous tree, the probable ancestor of present-day ''Hymenaea'' species. Most neotropical ambers come from its fossilized resin, including the famous Dominican amber. ''H. protera'' once grew in ...

'', which formerly grew on

, across northern South America, and up to southern Mexico. The specimen was collected from an undetermined amber mine in fossil-bearing rocks of the

Cordillera Septentrional The Cordillera Septentrional is a mountain range that runs parallel to the north coast of the Dominican Republic, with extensions to the northwest as Tortuga island in Haiti, and to the southeast through lowlands to where it rises as the Sierra d ...

mountains of northern

Dominican Republic The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares wit ...

. The amber dates from the

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

stage of the Miocene, based on studying the associated fossil

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and ot ...

, and may be as old as the Middle Eocene, based on the associated fossil

coccoliths Coccoliths are individual plates or scales of calcium carbonate formed by coccolithophores (single-celled phytoplankton such as ''Emiliania huxleyi'') and cover the cell surface arranged in the form of a spherical shell, called a ''coccosphere''. ...

. This age range is due to the host rock being secondary deposits for the amber, and the Miocene as the age range is only the youngest that it might be. 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 ...

specimen, number "BMNHP-II32", was preserved in the

Natural History Museum, London The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum an ...

amber collections in

London London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. The holotype fossil was first studied by entomologist Maria L. De Andrade of the

University of Basle The University of Basel (Latin: ''Universitas Basiliensis'', German: ''Universität Basel'') is a university in Basel, Switzerland. Founded on 4 April 1460, it is Switzerland's oldest university and among the world's oldest surviving universitie ...

with her 1994

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 ''Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie)''. 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 ...

''pseudobauri'' is derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

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 ...

word ''pseudo'' which means "false", and ''bauri'' from the modern species ''

Odontomachus bauri ''Odontomachus bauri'' is a species of ponerinae ant known as trap jaw ants. The trap jaw consists of mandibles which contain a spring-loaded catch mechanism. This mechanism permits the ants to accumulate energy before striking or releasing the ...

''.

Odontomachus pseudobauri BMNHP-II32 head dorsal

Based on the head structure, ''O. pseudobauri'' was suggested to be part of the ''O. haematodus'' species group, closely placed with the species ''O. bauri''. The modern species is found in the Galapagos islands, tropical regions of South and Central America, and most of the West Indies except the Bahamas and Cuba. ''O. bauri'' is one of two modern species found on the island of Hispaniola, and based on the similarities to ''O. pseudobauri'' De Andrade suggested the latter species might have been ancestral to the modern species. When first described, ''O. pseudobauri'' was one of two ''Odontomachus'' species that had been described from fossils. It and ''

Odontomachus spinifer ''Odontomachus spinifer'' is an extinct species of ant in the subfamily Ponerinae known from one possibly Miocene fossil found on Hispaniola. ''O. spinifer'' is one of two species in the ant genus ''Odontomachus'' to have been described from fos ...

'' were both described by De Andrade from Dominican amber in the same paper. A third species '' Odontomachus paleomyagra'', the first compression fossil species, was described in 2014 from a worker found in

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 ...

age

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,

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

Description

The ''O. pseudobauri'' worker is approximately in length, and has a shining exoskeleton of orange along the body, reddish head and mandibles, and brownish tones on the gaster. The smooth exoskeleton has tiny punctuation found across the rear and sides of the head, in the front areas of the antennae depressions, and over the gaster. In contrast the frons back across the rear areas of the antennae sockets are striated, with the striae becoming finer towards the rear of the depressions. The head has a rectangular outline, being 1/3 longer than wide, with the rear margin of the head wider than the maximum width of the

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on ea ...

. The mandibles are 3/4 as long as the head is wide and the chewing margin of the right mandible having 14 teeth, while there are 13 teeth in the left. The teeth of both margins increase in size towards the tip, while the apex of each has three teeth, a preapical, intercalary, and an apical tooth. The antennae have notably long scapes that extend past the rear margin of the head capsule. The first funicular segments of the antennae are 3/4 the length of the second segment. The

and

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 ...

each have convex upper profiles, with approximately 25 concentric striae circling the pronotum. There is a large backward curving spine formed from the upper domed surface of the petiole, being a little narrower than the width of the petiole, and a smaller process is positioned on the forward underside area of the petiole. The worker is incomplete, missing the legs and antenna of the left side plus tip sections of the right legs. The third through end segments of the gaster are shrunken and missing.

References

External links

{{Taxonbar, from=Q14444357 †Odontomachus pseudobauri Fossil ant taxa Hymenoptera of North America Burdigalian life Neogene Dominican Republic Miocene insects of North America Prehistoric insects of the Caribbean Fauna of Hispaniola Insects of the Dominican Republic Fossils of the Dominican Republic Dominican amber Fossil taxa described in 1994