Formicodiplogaster myrmenema

Formicodiplogaster is an extinct form genus of nematodes in the family Diplogasteridae which currently includes a single described species Formicodiplogaster myrmenema. The species is known from early Miocene fossils found on Hispaniola. F. myrmenema has been preserved in association with Azteca alpha, one of only two species in the ant genus Azteca.

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, which formerly grew on Hispaniola, 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 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. of Oregon State University, with his 2011 type description 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".