''Cephalotes alveolatus'' 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

Myrmicinae Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...

known from a single

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

fossil found in

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Ma ...

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 ...

. At the time of description ''C. alveolatus'' was one of seven fossil ant species placed in the ''Cephalotes'' ''coffeae'' clade.

History and classification

''Cephalotes alveolatus'' was described from a single fossil ant preserved as an

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, aims to create an environment that supports equal opportunity for individuals and groups that form a society. ** Inclusion (disability rights), promotion of people with disabiliti ...

in a transparent chunk 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 specimen was collected from an unidentified amber mine in the

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 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 being recovered from sections of the

La Toca Formation The La Toca Formation is a geologic formation in the northern and eastern part of the Dominican Republic. The formation, predominantly an alternating sequence of marls and turbiditic sandstones, breccias and conglomerates, is renowned for the p ...

in 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 ...

and the Yanigua Formation in the Cordillera Oriental. 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 several ...

specimen was preserved in the private collection of Joachim Scheven in Hagen, Germany. The fossil was first studied by researchers Gijsbertus Vierbergen and Joachim Scheven with their 1995

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 being published in the ''Creation Research Society quarterly''. They placed the species into the genus ''Zacryptocerus'', and coined 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 ...

''alveolatus'' as a reference to the many small pits on the head and body of the worker. Living and fossil species of the genera ''Cephalotes'', ''Eucryptocerus'', ''Exocryptocerus'' and ''Zacryptocerus'' were examined in 1999 by Maria L. De Andrade and Cesare Baroni Urbani with a redescription of the ''Cephalotes'' being published in the journal ''Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie)''. De Andrade and Baroni Urbani concluded that ''Cephalotes'' was

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

if the species placed in the other three genera were not included within the genus. As a result, ''Zacryptocerus alveolatus'' was moved to ''Cephalotes'' as ''C. alveolatus''. The authors examined the type specimen, then still in Scheven collection, and an additional fossil worker housed in the Staatliches Museum fiir Naturkunde and placed into the species. They noted that the holotype specimen is damaged due to burning, and as such the original coloration of the worker is unidentifiable, and the integument is partially fragmented.

Phylogeny

In the study of ''Cephalotes'' by de Andrade and Baroni Urbani ''C. alveolatus'' was grouped into the ''coffeae'' clade consisting of seven extinct species and four extant species. The clade shares two, possibly three distinct features between the species. Segment three of the abdomen is modified into a post petiole which in turn is modified to have large side wings. Additionally the first

sternite The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the ...

of the gaster has a simple reticulated surface sculpturing. ''C. alveolatus'' was consistently placed as the outgroup species to the other members of the clade in de Andrade and Baroni Urbani's phylogenies, with it sharing several features with other clade species but having large amounts of distinct clubbed hairs.

Description

The two workers known have body lengths between , and heads that range between . The coloration seen on specimen DO-I 980 indicates black tones on the ridges and rear corners of the head along with the lamellae edges which border the

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 ea ...

. The front edges of the lamellae on the gaster are rust colored and semi-transparent. The head is almost square in outline, with broadly curved rear corners and a concave rear margin sporting two denticles. Raised ridges on the front area of the head run above the eyes and have a scalloped edge. There are a pair of round to obtuse shaped teeth flanking the sides of the mesonotum, and the propodum edges are marked with small teeth or angles. Similarly, the sides of the petiole have a pair of teeth, while the postpetiole has larger side teeth near its front that angle forward. The upper surface of the postpetile has a groove along its middle, flanked by two raised ridges. Four different types of hairs are present on the workers. On the gaster

s sparse long pointed hairs, and long clubbed hairs are present. Similar to the long clubbed hairs are short clubbed hairs present in dense amounts on the gaster, legs and postpetiole segment, and in sparser amounts on the

mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. In hymenopterans of t ...

sides, corners of the head and on the cernulations of the facial ridges. Lastly there are recumbent hairs on the first segment of the gaster, not originating from exoskeleton depressions, and originating from depressions across the rest of the body.

References

External links

* {{Taxonbar, from=Q5063350 alveolatus Fossil ant taxa Miocene insects Burdigalian life Hymenoptera of North America Prehistoric insects of the Caribbean Fauna of Hispaniola Neogene Dominican Republic Fossils of the Dominican Republic Dominican amber Fossil taxa described in 1995