''Tyrannomyrmex'' is a rare

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of ants in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

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 ...

. Three similar

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 ...

, only known from workers, are recognized and share small eyes and edentate mandibles.

Species

Two of the species are known only from single worker specimens, but a single male specimen collected in 1965 possibly represents the male of an otherwise unknown species, and ''T. alii'' is known from a series of over 35 gynes and workers. So far, all species of ''Tyrannomyrmex'' occur in tropical

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...

forests. The wide distribution range from India and Sri Lanka in the west to

peninsular Malaysia Peninsular Malaysia ( ms, Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), or the States of Malaya ( ms, Negeri-negeri Tanah Melayu; Jawi: نڬري-نڬري تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, ...

and perhaps the

Philippine archipelago The islands of the Philippines, also known as the Philippine Archipelago, comprises about 7,641 islands, of which only about 2,000 are inhabited. * '' Tyrannomyrmex alii'' Sadasivan & Kripakaran, 2017 - Western Ghats,

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

* '' Tyrannomyrmex dux'' Borowiec, 2007 –

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...

* '' Tyrannomyrmex legatus'' Alpert, 2013 –

Sinharaja Forest Reserve Sinharaja Forest Reserve is a forest reserve and a biodiversity hotspot in Sri Lanka. It is of international significance and has been designated a Biosphere Reserve and World Heritage Site by UNESCO. According to International Union for Conser ...

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

* '' Tyrannomyrmex rex'' Fernández, 2003 –

Negri Sembilan Negeri Sembilan (, Negeri Sembilan Malay: ''Nogoghi Sombilan'', ''Nismilan'') is a States and federal territories of Malaysia, state in Malaysia which lies on the Peninsular Malaysia#Other features, western coast of Peninsular Malaysia. It bor ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

For the first time in a decade, in 2017, the extremely rare ant was seen alive, living in the dirt of Singapore's Mandai area, according to a report by National Geographic.

Taxonomy

In 2003, Fernández described a new genus and species, '' Tyrannomyrmex rex'', from

based on a single specimen collected from leaf litter at

, Pasoh Forest Reserve in 1994. Fernández was unable to place the new genus in any existing myrmicine tribe although several potential candidates were considered including the Adelomyrmecini and Solenopsidini. Without additional specimens or molecular data this genus was temporarily placed as '' incertae sedis'' within the subfamily Myrmicinae. A second species, '' T. dux'', was described by Borowiec (2007) based on a single specimen collected from leaf litter in southern India in 1999. A single worker of a third species, '' T. legatus'', described Alpert (2013) was collected in 2006 from leaf litter in a lowland

dipterocarp Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...

undisturbed forest in southern Sri Lanka. This species is generally similar to the two previously described species of ''Tyrannomyrmex''. Fernández (2003) provisionally concluded that ''Tyrannomyrmex'' is a distinct and isolated myrmicine genus with possible affinities to either the ''

Adelomyrmex ''Adelomyrmex'' is a genus of ants in the subfamily Myrmicinae. Species of ''Adelomyrmex'' are small, litter-inhabiting ants most often collected in Berlese and Winkler samples. Although the genus and its relatives have a pantropical distribu ...

''-genus group or the tribe Solenopsidini. Alpert (2013), based on Bolton's (2003) lists of character states for all ant genera, placed the genus within Solenopsidini and close to the genus ''

Monomorium ''Monomorium'' is a genus of ants in the subfamily Myrmicinae. As of 2013 it contains about 396 species. It is distributed around the world, with many species native to the Old World tropics. It is considered to be "one of the more important grou ...

''.

Tyrannomyrmex legatus CASENT0106177 profile

Description

All species have small eyes reduced to a few

ommatidia The compound eyes of arthropods like insects, crustaceans and millipedes are composed of units called ommatidia (singular: ommatidium). An ommatidium contains a cluster of photoreceptor cells surrounded by support cells and pigment cells. The ou ...

, an 11-segmented

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

with an ill-defined 3-segmented club,

papal The pope ( la, papa, from el, πάππας, translit=pappas, 'father'), also known as supreme pontiff ( or ), Roman pontiff () or sovereign pontiff, is the bishop of Rome (or historically the patriarch of Rome), head of the worldwide Cathol ...

formula 2-2, and a masticatory border largely edentate with two apical teeth. The small eyes, edentate mandibles, and close similarity among the workers of all three ''Tyrannomyrmex'' species strongly suggest that they may also be similar ecologically, and that they are probably subterranean and predaceous. While the three known worker specimens have been taken in leaf litter samples, the rarity of collections suggests that ''Tyrannomyrmex'' species may both nest and forage in the deeper soil horizons, and that foragers may only occasionally enter the leaf litter layers closer to the surface.

Morphological characters

Tyrannomyrmex alii NCBS-AV849 left profile

Alpert (2013) summarized the morphological characters for the genus as follows: *Mandibles with two teeth in the masticatory border, apical and smaller subapical. No teeth on the basal margin of the mandible. *Inner ventral margin of masticatory border of mandibles with setae. Setae can be normal or modified. * Clypeus devoid of carinae. Foveolae may be present. *Palpal formula 2, 2. * Compound eyes small, reduced to a few

. *Antennae 11-segmented with an ill-defined 3-segmented club. *Frontal carinae and antennal scrobes absent. *

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 ...

without promesonotal suture. *Propodeal lobes large and round. *Sting large and robust.

References

* * * * *

External links

* {{Taxonbar, from=Q4051906 Myrmicinae Ant genera Hymenoptera of Asia