''Formicodiplogaster'' 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 ...

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 ...

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

s in the family Diplogasteridae 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 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 th ...

. ''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 fo ...

'', 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. 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 mountains, northern Dominican Republic. The amber dates from at least the Burdigalian stage of the Miocene, based on studying the associated fossil foraminifera and may be as old as the Middle Eocene, based on the associated fossil coccoliths. 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

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 l ...

larva, in addition to the paratype larvae, adults and juveniles, were preserved in the Poinar amber collection at Oregon State University. 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 Cr ...

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 ''Formicodiplogaster'' is derived from the Latin ''formica'', meaning "ant", and the nematode genus '' Diplogaster'', while the specific epithet is a derivation of the Greek ''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