Armaniinae is subfamily of

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 ...

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 ...

-like hymenopterans known from a series of

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

fossils found in Asia and Africa. It is usually treated as one of the stem-group subfamilies in family Formicidae, although some myrmecologists treat it as a distinct family. A 2007 study analysing petiole and antenna morphology led to the proposal that at least some of the armaniid genera be placed in

Sphecomyrminae Sphecomyrminae is an extinct subfamily of ants in family Formicidae known from a series of Cretaceous fossils found in North America, Europe, and Asia. Sphecomyrminae contains eight genera, divided into two tribes Sphecomyrmini and Zigrasimeciin ...

, although others are unconvinced by the arguments and retain Armaniinae. The subfamily contains seven genera with fourteen described species.

History and classification

Armaniinae is sometimes treated as the most basal of the Formicidae subfamilies, and classed as a stem-group which is more distant in relation to modern ants than the next stem group,

. Alternatively, the group has been treated as "ant-like wasps", and elevated to the rank of family as Armaniidae, and considered as a possible

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to Formicidae. It has been suggested by Engel and Grimaldi that the group may be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

. This position is in contrast to the original hypothesis of Russian paleoentomologist Gennady Dlussky, who first described the family. Dlussky considered the group, when erected in 1983, have been an intermediate family bridging the families Scoliidae and the true formicids. In contrast to both the treatment as a separate family and as a distinct subfamily, entomologist E. O. Wilson, in a 1987 paper, suggested that the then known armaniids and '' Sphecomyrma'' represented a single species. Wilson, in synonymizing the groups, made the hypothesis that the different described genera were actually fossils of different castes of the same species, with ''Sphecomyrma freyi'' being workers, ''Armania robusta'' being queens, and '' "Paleomyrmex" zherichini'' as the winged males. This view was rejected as new fossils and species were described. The group is known exclusively from impression fossils, which have a limited preservation quality, leading to the uncertainty of what features are present in the described species. Overall armaniids have a poorly developed petiole which is broadly attached to the

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

, short scapes on the antennae, and queen-like looking females. The mandibles are vespid like, with possibly only one or two teeth, though this may be an artifact of preservation. The short scape is a feature that is also seen in Sphecomyrminae members, and does not exclude armaniids from Formicidae. Similarly the petiole is a feature that is seen in both the true formicids, and in the extinct chrysidoid wasp family Falsiformicidae, which is not related to formicids at all. The two defining features of the true formicids are considered to be the presence of females which are divided into adult workers and queens. Currently no worker like armaniid specimens are known for the described species. The presence of

metapleural gland Metapleural glands (also called metasternal or metathoracic glands) are secretory glands that were considered unique to ants and basal in the evolutionary history of ants. They are responsible for the production of an antibiotic fluid that then col ...

s in some fossils has been reported by Dlussky,± but the veracity of the presence is uncertain. A review of the Cretaceous ant groups was performed by Borysenko in 2017 leading to the breakup of Armaniidae, with the three genera '' Armania'', '' Orapia'', and '' Pseudarmania'' being moved to

. The genera '' Archaeopone'' and '' Poneropterus'' were considered as ''incertae sedis'' in Formicidae, and the genera '' Dolichomyrma'' and '' Khetania'' were removed from the family entirely as ''incertae sedis'' in

Aculeata Aculeata is an infraorder of Hymenoptera containing ants, bees, and stinging wasps. The name is a reference to the defining feature of the group, which is the modification of the ovipositor into a stinger. However, many members of the group cann ...

Genera and species

*'' Archaeopone'' Dlussky, 1975 **''Archaeopone kzylzharica'' Dlussky, 1975 **''Archaeopone taylori'' Dlussky, 1983 *'' Armania'' Dlussky, 1983 (jr synonym = "''Armaniella''" Dlussky, 1983) **''Armania capitata'' Dlussky, 1983 **''Armania curiosa'' (Dlussky, 1983) **''Armania pristina'' Dlussky, 1983 **''Armania robusta'' Dlussky, 1983 *'' Dolichomyrma'' Dlussky, 1975 **''Dolichomyrma latipes'' Dlussky, 1975 **''Dolichomyrma longiceps'' Dlussky, 1975 *'' Khetania'' Dlussky, 1999 **''Khetania mandibulata'' Dlussky, 1999 *'' Orapia'' Dlussky, Brothers & Rasnitsyn, 2004 **''Orapia minor'' Dlussky, Brothers & Rasnitsyn, 2004 **''Orapia rayneri'' Dlussky, Brothers & Rasnitsyn, 2004 *'' Poneropterus'' Dlussky, 1983 **''Poneropterus sphecoides'' Dlussky, 1983 *'' Pseudarmania'' Dlussky, 1983 **''Pseudarmania aberrans'' Dlussky, 1983 **''Pseudarmania rasnitsyni'' Dlussky, 1983

References

{{Taxonbar, from1=Q33137630, from2=Q4034379 † Fossil ant taxa Cenomanian first appearances Turonian extinctions