Myrmeciinae is a subfamily of the Formicidae, ants once found worldwide but now restricted to Australia and New Caledonia. This subfamily is one of several ant subfamilies which possess gamergates, female worker ants which are able to mate and reproduce, thus sustaining the colony after the loss of the queen. The Myrmeciinae subfamily was formerly composed of only one genus, Myrmecia, but the subfamily was redescribed by Ward & Brady in 2003 to include two tribes and four genera. An additional three genera, one form genus, and 9 species were described in 2006 from the Early Eocene of Denmark, Canada, and Washington. Subsequently an additional fossil genus was moved from the family Rhopalosomatidae in 2018, and a new genus was described in 2021.
Nothomyrmecia, also known as the dinosaur ant or dawn ant, is an extremely rare genus of ants consisting of a single species, Nothomyrmecia macrops. These ants live in South Australia, nesting in old-growth mallee woodland and Eucalyptus woodland. The full distribution of Nothomyrmecia has never been assessed, and it is unknown how widespread the species truly is; its potential range may be wider if it does favour old-growth mallee woodland. Possible threats to its survival include habitat destruction and climate change. Nothomyrmecia is most active when it is cold because workers encounter fewer competitors and predators such as Camponotus and Iridomyrmex, and it also increases hunting success. Thus, the increase of temperature may prevent them from foraging and very few areas would be suitable for the ant to live in. As a result, the IUCN lists the ant as Critically Endangered.
Myrmecia inquilina is a species of ant endemic to Australia in the subfamily Myrmeciinae, first discovered in 1955 and described by Athol Douglas and William Brown Jr. in 1959. These ants are large, measuring 21.4 millimetres (0.84 in). During the time of its discovery, Douglas and Brown announced M. inquilina as the first social parasite among the primitive subfamilies, and today it is one of the two known Myrmecia species to have no worker caste. Two host species are known, Myrmecia nigriceps and Myrmecia vindex. Aggression between M. inquilina and its host species does not occur, and colonies may only produce M. inquilina brood months after the inquiline queens begin to lay their eggs. Queens eat the colony brood or trophic eggs, and other Myrmecia species may kill M. inquilina queens if they reject them. Due to its restricted distribution and threats to its habitat, the ant is "vulnerable" according to the IUCN Red List.
Sphecomyrma is an extinct genus of ants which existed in the Cretaceous approximately 79 to 92 million years ago. The first specimens were collected in 1966, found embedded in amber which had been exposed in the cliffs of Cliffwood, New Jersey, by Edmund Frey and his wife. In 1967, zoologists E. O. Wilson, Frank Carpenter and William L. Brown, Jr. published a paper describing and naming Sphecomyrma freyi. They described an ant with a mosaic of features—a mix of characteristics from modern ants and aculeate wasps. It possessed a metapleural gland, a feature unique to ants. Furthermore, it was wingless and had a petiole which was ant-like in form. The mandibles were short and wasp-like with only two teeth, the gaster was constricted, and the middle and hind legs had double tibial spurs. The antennae were, in form, midway between the wasps and ants, having a short first segment but a long flexible funiculus. Three additional species, S. canadensis, S. mesaki and S. nexa, were described in 1985, 2005, and 2024, respectively.
Prionomyrmex is an extinct genus of bulldog ants in the subfamily Myrmeciinae of the family Formicidae. It was first described by Gustav Mayr in 1868, after he collected a holotype worker of P. longiceps in Baltic amber. Three species are currently described, characterised by their long mandibles, slender bodies and large size. These ants are known from the Eocene and Late Oligocene, with fossil specimens only found around Europe. It is suggested that these ants preferred to live in jungles, with one species assumed to be an arboreal nesting species. These ants had a powerful stinger that was used to subdue prey. In 2000, it was suggested by Cesare Baroni Urbani that the living species Nothomyrmecia macrops and a species he described both belonged to Prionomyrmex, but this proposal has not been widely accepted by the entomological community. Instead, scientists still classify the two genera distinctive from each other, making Nothomyrmecia a valid genus.
Cephalotes dieteri is an extinct species of ant in the subfamily Myrmicinae known from two Middle Miocene fossils found in amber on Hispaniola. At the time of description, C. dieteri was one of seven fossil ant species placed in the Cephalotescoffeae clade.
Ypresiomyrma is an extinct genus of ants in the subfamily Myrmeciinae that was described in 2006. There are four species described; one species is from the Isle of Fur in Denmark, two are from the McAbee Fossil Beds in British Columbia, Canada, and the fourth from the Bol’shaya Svetlovodnaya fossil site in Russia. The queens of this genus are large, the mandibles are elongated and the eyes are well developed; a stinger is also present. The behaviour of these ants would have been similar to that of extant Myrmeciinae ants, such as solitary foraging for arthropod prey and never leaving pheromone trails. The alates were poor flyers due to their size, and birds and animals most likely preyed on these ants. Ypresiomyrma is not assigned to any tribe, and is instead generally regarded as incertae sedis within Myrmeciinae. However, some authors believe Ypresiomyrma should be assigned as incertae sedis within Formicidae.
Macabeemyrma is an extinct genus of bulldog ants in the subfamily Myrmeciinae containing the single species Macabeemyrma ovata, described in 2006 from Ypresian stage deposits of British Columbia, Canada. Only a single specimen is known; a holotype queen found preserved as a compression fossil. The specimen had no wings and small portions of its legs and eyes were faintly preserved. It was a large ant, reaching 25 millimetres (0.98 in) in length. This ants' behaviour would have been similar to that of extant Myrmeciinae ants, such as foraging singly in search for arthropod prey and nesting in soil or in trees. Macabeemyrma shows similarities to extinct ants in the genus Ypresiomyrma, and to the living Nothomyrmecia macrops, but has not been conclusively assigned to any tribe, instead generally regarded as incertae sedis within Myrmeciinae. However, the sole specimen lacks definitive traits, and its classification in Myrmeciinae, and even its identity as an ant, has been challenged.
Myrmeciites is an extinct form genus of bulldog ants in the subfamily Myrmeciinae of the family Formicidae, which contains three described species and two fossils not placed beyond the genus level. Described in 2006 from Ypresian stage deposits, all three of the described species and one unplaced fossil are from British Columbia, Canada, while the second unplaced fossil is from Washington State, USA. These ants were large, with the largest specimens collected reaching 3 centimetres (1.2 in). The behaviour of these ants would have been similar to extant Myrmeciinae ants, such as solitary foraging, nesting either in the soil or trees, and leaving no pheromone trail to food sources. Due to the poor preservation of these ants, their phylogenetic position among Myrmeciinae is unclear, and no type species has been designated. These ants are classified as incertae sedis in Myrmeciinae, but some writers have classified it as incertae sedis within the insect order Hymenoptera. This reclassification, however, has not been accepted; instead, Myrmeciites remains in Myrmeciinae.
Prionomyrmecini is an ant tribe belonging to the subfamily Myrmeciinae established by William Morton Wheeler in 1915. Two members are a part of this tribe, the extant Nothomyrmecia and the extinct Prionomyrmex. The tribe was once considered a subfamily due to the similarities between Nothomyrmecia and Prionomyrmex, but such reclassification was not widely accepted by the scientific community. These ants can be identified by their long slender bodies, powerful stingers and elongated mandibles. Fossil Prionomyrmecini ants were once found throughout Europe, possibly nesting in trees and preferring jungle habitats. Today, Prionomyrmecini is only found in Australia, preferring old-growth mallee woodland surrounded by Eucalyptus trees. Nothomyrmecia workers feed on nectar and arthropods, using their compound eyes for prey and navigational purposes. Owing to their primitive nature, they do not recruit others to food sources or create pheromone trails. Nothomyrmecia colonies are small, consisting of 50 to 100 individuals.
Tatuidris, or armadillo ant, is a rare genus of ants consisting of a single species, Tatuidris tatusia. The ants are small in size and inhabit the leaf litter of Neotropical forests in Central and South America, from Mexico to Brazil. Workers are ferruginous-colored to dark red and present a distinctive morphology, consisting of a shield-like head with a broad vertex, ventrally-turned heavy mandibles which do not overlap at full closure, and unique among ants – an antenna socket apparatus sitting upside-down. Little is known about the biology of the ants, but they are likely nocturnal and specialist predators.
Brownimecia is an extinct genus of ants, the only genus in the tribe Brownimeciini and subfamily Brownimeciinae of the Formicidae. Fossils of the identified species, Brownimecia clavata and Brownimecia inconspicua, are known from the Late Cretaceous of North America. The genus is one of several ants described from Late Cretaceous ambers of New Jersey. Brownimecia was initially placed in the subfamily Ponerinae, until it was transferred to its own subfamily in 2003; it can be distinguished from other ants due to its unusual sickle-like mandibles and other morphological features that makes this ant unique among the Formicidae. B. clavata is also small, measuring 3.43 millimetres (0.135 in), and a stinger is present in almost all of the specimens collected. The morphology of the mandibles suggest a high level of feeding specialization.
Haidomyrmex is an extinct genus of ants in the formicid subfamily Haidomyrmecinae, and is one of nine genera placed in the subfamily Haidomyrmecinae. The genus contains three described species Haidomyrmex cerberus, Haidomyrmex scimitarus, and Haidomyrmex zigrasi. All three are known from single Late Cretaceous fossils which have been found in Asia. H. cerberus is the type species and Haidomyrmex the type genus for the subfamily Haidomyrmecinae.
Acanthostichus hispaniolicus is an extinct species of ant in the subfamily Dorylinae known from a group of possibly Miocene fossils found on the Caribbean island of Hispaniola. A. hispaniolicus is the first species of the ant genus Acanthostichus to have been described from fossils found in Dominican amber, and is the only species of Acanthostichus found in the West Indies.
Acanthognathus poinari is an extinct species of ant in the subfamily Myrmicinae known from a single possibly Miocene fossil found on Hispaniola. A. poinari is the first species of the ant genus Acanthognathus to have been described from fossils found in Dominican amber and is one of several species of Acanthognathus found in the Greater Antillas.
Anochetus corayi is an extinct species of ant in the subfamily Ponerinae known from one possibly Miocene fossil found on Hispaniola. A. corayi is one of eight species in the ant genus Anochetus to have been described from fossils found in Dominican amber and is one of a number of Anochetus species found in the Greater Antillies.
Archimyrmex is an extinct genus of ant in the formicid subfamily Myrmeciinae, described by palaeoentomologist Theodore Cockerell in 1923. The genus contains four described species, Archimyrmex rostratus, Archimyrmex piatnitzkyi, Archimyrmex smekali and Archimyrmex wedmannae. Archimyrmex is known from a group of Middle Eocene fossils which were found in North America, South America, and Europe. The genus was initially placed in the subfamily Ponerinae, but it was later placed in Myrmeciinae; it is now believed to be the ancestor of the extant primitive genus Myrmecia from Australia. Despite this, Archimyrmex is not a member to any tribe and is regarded as incertae sedis within Myrmeciinae. However, some authors believe Archimyrmex should be assigned as incertae sedis within Formicidae. These ants can be characterised by their large mandibles and body length, ranging from 13.2 to 30 mm. They also have long, thin legs and an elongated mesosoma (thorax) and petiole.
Myanmyrma is an extinct genus of ants not placed into any Formicidae subfamily. Fossils of the single known species, Myanmyrma gracilis, are known from the Middle Cretaceous of Asia. The genus is one of several ants described from Middle Cretaceous ambers of Myanmar.
Gerontoformica is an extinct genus of stem-group ants. The genus contains thirteen described species known from Late Cretaceous fossils found in Asia and Europe. The species were described between 2004 and 2016, with a number of the species formerly being placed into the junior synonym genus Sphecomyrmodes.
Bradoponera is an extinct genus of ant in the Formicidae subfamily Proceratiinae, and is one of four genera of the subfamily. The genus contains four described species Bradoponera electrina, Bradoponera meieri, Bradoponera similis, and Bradoponera wunderlichi. The species are known from several Middle Eocene amber fossils which were found in Europe.
