''Acanthostichus hispaniolicus'' 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

Dorylinae Dorylinae is an ant subfamily, with distributions in both the Old World and New World. Brady ''et al.'' (2014) synonymized the previous dorylomorph subfamilies (Aenictinae, Aenictogitoninae, Cerapachyinae, Ecitoninae, and Leptanilloidinae) under ...

known from a group of 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 ...

fossils found on the

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...

island of

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 ...

. ''A. hispaniolicus'' is the first species of the ant genus ''

Acanthostichus ''Acanthostichus'' is a predatory and predominantly subterranean genus of ant in the subfamily Dorylinae. They are found in the New World, from the southern United States to Uruguay, Paraguay and northern Argentina Argentina (), offici ...

'' 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 the only species of ''Acanthostichus'' found in the West Indies.

History and classification

''Acanthostichus hispaniolicus'' is known from four fossils insects which are inclusions in a single, transparent chunk of

. 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 amber specimens, numbers Do-5205-1, Do-5205-2, Do-5205-3, and Do-5205-4; which entomb 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 ...

and three

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). Of ...

s, are currently preserved in the Division of Invertebrate Zoology collections at the in

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the ...

, Germany. The holotype and paratype fossils are composed of complete adult workers which were originally preserved in the same amber specimen along with a number of other insects. The specimen, now cut into smaller pieces, 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, 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 at least 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 the age range is only the youngest that it might be. The fossils were first studied by paleoentomologist Maria De Andrade of the

University of Basel 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 universit ...

. De Andrade's 1998

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 was published in the Swiss journal ''Mitteilungen der Schweizerischen Entomologischen Gesellschaft''. 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 ...

''hispaniolicus'' is in reference island of Hispaniola where the fossil was found.

Description

The ''Acanthostichus hispaniolicus'' specimens are well preserved, though each of the four show some distortion from the amber moving after entombment. The specimens have estimated body lengths between . The overall coloration of ''A. hispaniolicus'' is a light orange-brown, with some darkening on the mandibles, the tarsomeres and the tarsi. The mandibles have between 6 and 8 minute teeth followed by a preapical tooth a short gap, and the apical tooth. The mouth is bracketed by a pair of three segmented labial palps and a pair of two segmented maxillary palps. The bodies have a flattened appearance in side view with a smooth and shining appearance and minute reticulation on portions of the gaster. The sting is noted to be well developed and long.

References

External links

* {{Taxonbar, from=Q15122246 Dorylinae Fossil ant taxa Burdigalian life Miocene insects of North America Prehistoric insects of the Caribbean Fauna of Hispaniola Extinct animals of the Dominican Republic Insects of the Dominican Republic Fossils of the Dominican Republic Dominican amber Fossil taxa described in 1998