''Anochetus intermedius'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

in the subfamily

Ponerinae Ponerinae, the ponerine ants, 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 replac ...

known from two possibly

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

fossils found on

Hispaniola Hispaniola (, also ) is an island between Geography of Cuba, Cuba and Geography of Puerto Rico, Puerto Rico in the Greater Antilles of the Caribbean. Hispaniola is the most populous island in the West Indies, and the second-largest by List of C ...

. ''A. intermedius'' is one of eight species in the ant genus ''

Anochetus ''Anochetus'' is a genus of small, carnivorous ants found in the tropics and subtropics The subtropical zones or subtropics are geographical and climate zones immediately to the north and south of the tropics. Geographically part of the ...

'' 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 in ...

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

Greater Antilles The Greater Antilles is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, and Jamaica, together with Navassa Island and the Cayman Islands. Seven island states share the region of the Greater Antille ...

History and classification

''Anochetus intermedius'' is known from a solitary fossil insect which, along with two flies, three other ants, and two

springtail Springtails (class Collembola) form the largest of the three lineages of modern Hexapoda, hexapods that are no longer considered insects. Although the three lineages are sometimes grouped together in a class called Entognatha because they have in ...

s, is an

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, action taken to support people of different backgrounds sharing life together. ** Inclusion (disability rights), promotion of people with disabilities sharing various aspects of lif ...

in a transparent yellow chunk of

. The amber was produced by the extinct '' Hymenaea protera'', 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 is a country located on the island of Hispaniola in the Greater Antilles of the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean. It shares a Maritime boundary, maritime border with Puerto Rico to the east and ...

. 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 unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

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 only the youngest that it might be. At the time of description, the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen 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 (Lo ...

amber collections in

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

, England. The holotype fossil was first studied by entomologist Maria L. De Andrade of the University of Basle with her 1991 type description of the new species being published in the journal ''Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie)''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''intermedius'' meaning "intermediate". The species is one of eight ''Anochetus'' which have been described from Dominican amber. Two species were described prior to ''A. intermedius'', '' A. corayi'' in 1980 and '' A. brevidentatus'' in 1991. The remaining five species; '' A. ambiguus'', '' A. conisquamis'', '' A. dubius'', '' A. exstinctus'', and '' A. lucidus'' were all described by De Andrade in the same 1994 paper as ''A. intermedius''. A number of modern species live in the Greater Antilles, with at least three modern species found on Hispaniola.

Description

The ''Anochetus intermedius'' type specimen is fairly well preserved, though some body structures were lost prior to entombment and the specimen shows distortions along its full length from the resin flowing after entombment. The specimen has an estimated body length of , with a long head and long

mandibles In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

. The overall coloration of the body is a chestnut-yellow, with the coxae,

femora The femur (; : femurs or femora ), or thigh bone is the only bone in the thigh — the region of the lower limb between the hip and the knee. In many four-legged animals the femur is the upper bone of the hindleg. The top of the femur fits in ...

, trochanters and mandible blades a yellowish tone, while the head, mandible tips, antennae, tibiae and tarsi are all brownish. The mandibles are one quarter times longer than the width of the head and just over the length, slightly flaring in width from the base to tips and have seven teeth on the left mandible, eight teeth on the right, all of which decrease in size from the tips to the bases. The apical three teeth on each mandible blade are elongated and slender for grasping prey. Both the

mesonotum The mesothorax is the middle of the three segments of the thorax of hexapods, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are the mesonotum (dorsal), the mesosternum ( ventral), and the mesopleuron (lateral) ...

and

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 e ...

have a slight "u" shaped profile, with the undersides of each curved upwards. The propodium sports short spines, long, on the rear edge, while the petiole has longer spines, , centrally placed.

References

{{Taxonbar, from=Q3689949 †Anochetus intermedius Fossil ant taxa Burdigalian life Miocene insects of North America Prehistoric insects of the Caribbean Fauna of Hispaniola Insects of the Dominican Republic Dominican amber Fossil taxa described in 1994 Species known from a single specimen