''Formicodiplogaster'' is an extinct

form genus Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of s ...

of nematodes in the family

Diplogasteridae Diplogastridae, formerly Diplogasteridae, are a family of nematodes (roundworms) known from a wide range of habitats, often in commensal or parasitic associations with insects. Description Diplogastrid nematodes are characterized by a distinc ...

which currently includes a

single Single may refer to: Arts, entertainment, and media * Single (music), a song release Songs * "Single" (Natasha Bedingfield song), 2004 * "Single" (New Kids on the Block and Ne-Yo song), 2008 * "Single" (William Wei song), 2016 * "Single", by ...

described species ''Formicodiplogaster myrmenema''. The species is known from

early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was p ...

fossils 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 t ...

. ''F. myrmenema'' has been preserved in association with ''

Azteca alpha ''Azteca alpha'' is an extinct species of ant in the subfamily Dolichoderinae known from possibly Miocene fossils found on Hispaniola. ''A. alpha'' is one of only two species in the genus '' Azteca'' to have been described from fossils, both fou ...

'', one of only two known fossil species in the ant genus '' Azteca''.

History and classification

When described ''Formicodiplogaster myrmenema'' was described from approximately seven fossil nematodes which were group inclusions with ants in transparent chunks of

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 ...

. 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 specimens were collected from a number of amber mines 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 (Haiti), Tortuga island in Haiti, and to the southeast through lowlands to where it rises ...

mountains, 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 with ...

. The amber dates from at least the

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

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 for catching food and other uses; and commonly ...

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 the age range is 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 seve ...

dauer stage Dauer (German "''die Dauer''", English "the enduring", "the duration" in the meaning of "a length of time",) describes an alternative developmental stage of nematode worms, particularly rhabditids including ''Caenorhabditis elegans'', whereby the ...

larva, in addition to the

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

larvae, adults and juveniles, were preserved in the Poinar amber collection at

Oregon State University Oregon State University (OSU) is a Public university, public Land-grant university, land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degree ...

. The fossils were first studied by paleontologist

George Poinar Jr. George O. Poinar Jr. (born April 25, 1936) is an American entomologist and writer. He is known for popularizing the idea of extracting DNA from insects fossilized in amber, an idea which received widespread attention when adapted by Michael Cric ...

of Oregon State University, with his 2011

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 ...

of the new genus and species being published in the journal ''Nematology monographs and perspectives pages''. The

generic epithet Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomencla ...

''Formicodiplogaster'' is derived from 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 ...

''formica'', meaning "ant", and the nematode genus ''

Diplogaster ''Diplogaster'' is a genus of nematodes belonging to the family Diplogastridae. The species of this genus are found in Europe, Africa and Northern America. Species: *''Diplogaster australis'' *''Diplogaster gagarini'' *''Diplogaster intermedi ...

'', while the specific epithet is a derivation of 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 ...

''myrmex'', meaning ant, and ''nema'', meaning "thread". Portions of ant nests have been fossilized and identified and show an association of the extinct ant ''

'' colonies and ''Formicodiplogaster myrmenema''. The nests show active ant colonies in which adult and juvenile ''F myrmenema'' are present. Examples of

phoretic Phoresis or phoresy is a non-permanent, commensalistic interaction in which one organism (a phoront or phoretic) attaches itself to another (the host) solely for the purpose of travel. Phoresis has been observed directly in ticks and mites s ...

''F myrmenema'' are preserved as individuals in a

that was possibly carried in the abdominal intersegment membranes. The transition and transport of the dauer stage ''F myrmenema'' may have been a result of deteriorating conditions in the host colony. No direct evidence has been found for ''F. myrmenema'' living in the postpharyngeal glands or head glands of ''A. alpha''.

Description

Adult ''F myrmenema'' are long with rounded heads and tails that come to a point and the lips of the mouth are not offset. Similarly the dauer stage juveniles are the same general shape, with rounded heads and tapered tails, ranging from long.

References

{{Taxonbar, from=Q18355887 †Formicodiplogaster Prehistoric protostome genera Miocene animals of North America Burdigalian life Neogene Dominican Republic Fauna of Hispaniola Fossils of the Dominican Republic Dominican amber Fossil taxa described in 2011