''Attopsis'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 ...

s in the formicid subfamily

Formicinae The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development. Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and little ...

. While formerly containing a number of species, the genus is currently

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

; the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

, ''Attopsis longipennis'', is known from a single

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

found in what is now

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

History and classification

When described, the genus ''Attopsis'' was based on a group of 18 separate fossil ants, which were preserved as

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason f ...

s in sedimentary rock from the

Radoboj Radoboj is a village and municipality in Krapina-Zagorje County in Croatia. In the 2011 census, the total population was 3,387, in the following settlements: * Bregi Radobojski, population 445 * Gorjani Sutinski, population 145 * Gornja Šemn ...

area of what is now Croatia. The deposits are the result of sedimentation in an inland sea basin, possibly a shallow lagoon environment, during the

Burdigalian The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest w ...

of the Early Miocene. Along with ''Attopsis'', a diverse assemblage of several hundred species of insects has been preserved in the sediments, along with fish and algae. The fossil impressions are preserved in

micrite Micrite is a limestone constituent formed of calcareous particles ranging in diameter up to four μm formed by the recrystallization of lime mud. Flügel, Erik, ''Microfacies of Carbonate Rocks: Analysis, Interpretation and Application,'' Springe ...

limestones, resulting in low-quality preservation of fine details. The insect fossils were first studied by

Oswald Heer Oswald Heer (or Oswald von Heer) (31 August 1809 – 27 September 1883), Swiss geologist and naturalist, was born at Niederuzwil in Canton of St. Gallen and died in Lausanne. Biography Oswald Heer was educated as a clergyman at Halle an ...

, then a professor with the

University of Zürich The University of Zürich (UZH, german: Universität Zürich) is a public research university located in the city of Zürich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 f ...

, who placed the fossils in a new genus ''Attopsis''. The genus was based on the perceived structuring of the petiole as having two segments and the wing venation having an open mcu cell. Along with ''A. longipennis'', Heer described three other species, ''A. anthracina'', ''A. longipes'', and ''A. nigra''. The genus and many of the type specimens were reexamined and redescribed in 2014 by paleoentomologists Gennady Dlussky and Tatyana Putyatina, who determined that only the type specimen for ''A. longipennis'' matched a revised description of the genus, while all other fossils from the four species were redescribed as members of different genera. This revision resulted in only a single species in ''Attopsis''. The type specimens for ''A. anthracina'', ''A. longipes'', and ''A. nigra'' match the description for males of the species '' Oecophylla obesa'', and Dlussky and Putyatina designated the three species as junior synonyms of ''O. obesa''.

Description

The

gyne The gyne (, from Greek γυνή, "woman") is the primary reproductive female caste of social insects (especially ants, wasps, and bees of order Hymenoptera, as well as termites). Gynes are those destined to become queens, whereas female workers ...

for ''A. longipennis'' has a total length of , with only one segment to the petiole, while the first segment of the gaster is not constricted as Heer originally reported. Three sets of paired spines are on the propodium, 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 e ...

, and the petiole, respectively. The head has antennae with elongated scapes that protrude past the rear margin of the head capsule and have

flagellomere Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one o ...

s that are longer than they are wide. The margins of the compound eyes are rounded and lacking occipital angles. The fore wings are elongated and narrowed, with a closed 3r cell, while both the rm and mcu cells are possibly absent.

References

{{Taxonbar, from=Q9161819 Formicinae Fossil taxa described in 1849 Prehistoric insects of Europe Monotypic fossil ant genera Miocene insects