Agroecomyrmecinae

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Agroecomyrmecinae
Temporal range: Lutetian–Recent
Tatuidris tatusia casent0178882 profile 1.jpg
Tatuidris tatusia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Agroecomyrmecinae
Carpenter, 1930
Type genus
Agroecomyrmex
Wheeler, 1910
Tribes and genera

See text

Agroecomyrmecinae is a subfamily of ants containing two extant and two fossil genera. [1] The subfamily was originally classified in 1930 by Carpenter as Agroecomyrmecini, a Myrmicinae tribe. [2] Bolton raised the tribe to subfamily status in 2003, suggesting that Agroecomyrmecinae might be the sister taxon to Myrmicinae. It has since been discovered to be one of the earliest lineages of ants, a clade from the basal polytomy for all ants. [3] [4] In 2014, the subfamily was expanded to two tribes. The tribe Ankylomyrmini was moved from the subfamily Myrmicinae to Agroemyrmecinae. [5]

Contents

Tribes and genera

Taxonomy

Since the original description, the systematic status of the Agroecomyrmecini tribe has been the focus of intense debate. Bolton (2003) was the first to suggest the taxonomic instability of Tatuidris within Myrmicinae and raised the genus to the level of a new subfamily, the Agroecomyrmecinae, suggesting the Agroecomyrmecinae might be the sister taxon to Myrmicinae. This assessment was based on these diagnostic characters: [7] [8]

  1. large mandibles with mandibular masticatory margins that oppose at full closure but do not overlap
  2. eyes at extreme posterior apex of deep antennal scrobes
  3. clypeus very broadly triangular, broadly inserted between the frontal lobes
  4. antennal sockets and frontal lobes strongly migrated laterally, far apart and close to lateral margins of the head
  5. mesotibia and metatibia with pectinate spurs
  6. short and compact mesosoma
  7. a sessile petiole, in posterior view the tergite and sternite not equally convex
  8. an abdominal segment III (postpetiole) without tergosternal fusion, segment large and very broadly articulated to segment IV,
  9. a helcium in frontal view with the sternite bulging ventrally and overlapped by the tergite
  10. an abdominal segment IV with a complete tergosternal fusion, [note 1]
  11. abdominal segment IV with a stridulitrum on the pretergite
  12. the sternite of abdominal segment IV is reduced, the tergite is much larger than the sternite and strongly vaulted

The subfamily rank of the armadillo ants was reassessed by Baroni Urbani & de Andrade (2007) in their last systematic assessment of the dacetines. They analyzed a morphological dataset that included former dacetines, basicerotines, phalacromyrmecines, and Tatuidris, as well as other non-Myrmicinae taxa such as the Australian genus Myrmecia and the Neotropical genus Pseudomyrmex . This work was the first attempt to include Tatuidris as a terminal taxon in a morphological cladistic analysis. In their study, Baroni Urbani & de Andrade (2007) identified six morphological synapomorphies shared between Tatuidris and the dacetines, justifying the inclusion of the genus within Myrmicinae. These characters included: [9] [10]

  1. mandibles at rest opposing at least in part, instead of crossing
  2. a mandibular-torular index < 130
  3. reduction of maxillary palps from double-jointed to single-jointed
  4. reduced male mandibles
  5. presence of a two-segmented antennal club
  6. reduced number of antennal joints

In addition, two autapomorphies (a differently shaped petiolar tergum and sternum, and the eyes at or close to the apex of the antennal scrobe) separated Tatuidris from all other extant ant genera included in their study. [9] [11]

Unlike phylogenetic studies based on morphological traits, molecular analyses of the internal phylogeny of the ants have given strong evidence that the armadillo ants are neither closely related to nor nested within the Myrmicinae. Brady et al. (2006), Moreau et al. (2006) and Rabeling et al. (2008) reconstructed phylogenetic trees with the agroecomyrmecines inside the 'poneroid' group of subfamilies, close to the Paraponerinae, and gave support for the exclusion of the genus from the Myrmicinae, a subfamily located inside the 'formicoid' clade. [12] Given the early appearance of the Agroecomyrmecinae in the geologic record, the similarities of armadillo ants to Myrmicinae were hypothesized to represent convergence and/or retention of plesiomorphic forms. [13] [14]

Recently, Keller (2011) challenged the phylogenetic relationships of the poneromorph subfamilies (including Tatuidris). [14] [15]

Distribution

According to Brown & Kempf (1967), agroecomyrmecines were probably widespread in both hemispheres during the early Tertiary. [16] Agroecomyrmex is known from Early Eocene, Lutetian, Baltic amber dating to 44 million years (Myr) ago, and Eulithomyrmex from late Eocene, Priabonian, Florissant shale (34.1 Myr ago) in present-day Colorado, United States.

Tatuidris, rare but broadly distributed, [14] inhabits the leaf litter of Neotropical forests in Central and South America, from Mexico to French Guiana, [17] central Brazil, [18] and Amazonian Peru. [6] Ankylomyrma is known only from Western Africa. [19]

Notes

  1. This character was described incorrectly by Bolton (l.c.); in Tatuidris the tergosternal suture of the abdominal segment IV is strong but not fused. [9]

Related Research Articles

<span class="mw-page-title-main">Myrmicinae</span> Subfamily of ants with cosmopolitan distribution whose pupae do not create cocoons

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 in soil, rotting wood, under stones, or in trees.

<i>Anochetus</i> Genus of ants

Anochetus is a genus of small, carnivorous ants found in the tropics and subtropics throughout the world.

<i>Prionomyrmex</i> Extinct genus of ants

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.

<i>Diaphoromyrma</i> Genus of ants

Diaphoromyrma is a genus of ants in the subfamily Myrmicinae. It contains the single species Diaphoromyrma sofiae, known only from workers from the type locality in Bahia, Brazil. The genus is apparently close to Allomerus and Diplomorium in the Solenopsidini, but its tribal attribution remains uncertain.

<i>Thaumatomyrmex</i> Genus of ants

Thaumatomyrmex is a Neotropical genus of ants in the subfamily Ponerinae, found from Mexico to Brazil. They are notable for their pitchfork-shaped mandibles, which they use to capture millipedes of the order Polyxenida. The genus is a specialist predator of polyxenids, and one of only two ant genera known to prey upon polyxenids.

<i>Cephalotes alveolatus</i> Extinct species of ant

Cephalotes alveolatus is an extinct species of ant in the subfamily Myrmicinae known from a single Middle Miocene fossil found in amber on Hispaniola. At the time of description C. alveolatus was one of seven fossil ant species placed in the Cephalotescoffeae clade.

<i>Tatuidris</i> Genus of ants

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.

<i>Eulithomyrmex</i> Extinct genus of ants

Eulithomyrmex is an extinct genus of ant in the formicid subfamily Agroecomyrmecinae. The genus contains two described species, Eulithomyrmex rugosus and Eulithomyrmex striatus. Eulithomyrmex is known from a group of Late Eocene fossils which were found in North America.

<i>Agroecomyrmex</i> Extinct genus of ants

Agroecomyrmex is an extinct genus of ants in the formicid subfamily Agroecomyrmecinae, for which it is the type genus. The genus contains a single described species, Agroecomyrmex duisburgi. Agroecomyrmex is known from a group of Middle Eocene fossils which were found in Europe.

<i>Proceratium</i> Genus of ants

Proceratium is a rare genus of ants in the subfamily Proceratiinae. It is the type genus of the tribe Proceratiini, which in addition to Proceratium consists of two even rarer genera: the extant Discothyrea and the fossil genus Bradoponera.

<i>Protanilla</i> Genus of ants

Protanilla is a genus of subterranean ants in the subfamily Leptanillinae. Known from the Indomalayan realm, the genus contains about thirteen species. The genus was erected by Taylor (1990) for the type species P. rafflesi, described from workers from Peninsular Malaysia. Species in this genus have long and downcurved mandibles with peg-like tooth on the inner margins. Four species are known from China, one from Taiwan, one from Sri Lanka and a couple from India.

<i>Leptanilloides</i> Genus of ants

Leptanilloides is a genus of ants in the subfamily Dorylinae. Leptanilloides is an uncommonly collected genus with subterranean habits in the New World Andean and sub-Andean tropics.

<i>Octostruma</i> Genus of ants

Octostruma is a genus of ants in the subfamily Myrmicinae. The genus is found in the Neotropics.

<i>Calyptomyrmex</i> Genus of ants

Calyptomyrmex is a genus of ants in the subfamily Myrmicinae. The genus is distributed from Africa to India and east to New Caledonia. They are mainly found in the rainforest, where they forage alone or in small numbers.

<i>Perissomyrmex</i> Genus of ants

Perissomyrmex is a genus of ants in the subfamily Myrmicinae. It is known from the Neotropical and Oriental realms.

<i>Ankylomyrma</i> Genus of ants

Ankylomyrma is a genus of large arboreal ants in the subfamily Agroecomyrmecinae. It contains the single species Ankylomyrma coronacantha, the sole member of the tribe Ankylomyrmini. The genus is known from Africa. Nothing is known about their biology. The genus was moved from the subfamily Myrmicinae to Agroecomyrmecinae in 2014.

<i>Tyrannomyrmex</i> Genus of ants

Tyrannomyrmex is a rare tropical genus of ants in the subfamily Myrmicinae. Three similar species, only known from workers, are recognized and share small eyes and edentate mandibles.

<i>Archimyrmex</i> Extinct genus of ants

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.

References

  1. "Subfamily: Agroecomyrmecinae". antweb.org. AntWeb . Retrieved 3 January 2015.
  2. Carpenter 1930
  3. Ward 2007
  4. "Genus: Tatuidris". antweb.org. AntWeb . Retrieved 29 August 2013.
  5. Ward et al. 2014
  6. 1 2 Donoso 2012, p. 61
  7. Bolton 2003, p. 51
  8. Donoso 2012, pp. 61–62
  9. 1 2 3 Donoso 2012, p. 62
  10. Baroni Urbani & de Andrade 2007, p. 78
  11. Baroni Urbani & de Andrade 2007, pp. 80–81
  12. Ward 2007, pp. 555–557
  13. Ward 2011, p. 23
  14. 1 2 3 Donoso 2012, p. 63
  15. Keller 2011, p. 73
  16. Brown & Kempf 1967, p. 186
  17. Lacau et al. 2012, p. 4
  18. Vasconcelos & Vilhena 2002, p. 278
  19. Bolton 1981