Cephalotes

Common in the New World tropics, these ants have long attracted the attention of tropical biologists due to their unusual soldier caste with large armored heads that match the size and shape of their nest entrances. Turtle ant colonies nest in pre-existing arboreal cavities, and soldiers function as living doors to admit incoming foragers and effectively exclude potential intruders.

Cephalotes (119 species) consume a mostly herbivorous diet (Russell et al. 2009) supplemented by pollen, bird feces and vertebrate urine (Baroni Urbani and de Andrade 1997; Powell 2008).

Castes
Powell (2016) studied how nesting ecology has shaped the diversification of an elaborate soldier caste in the turtle ants. The evolution of more specialized soldier types was associated with substantial shifts in nest-entrance specialization, while in species with the most specialized soldier type, there was also a match between head sizes and entrance sizes within and across species. These findings suggest the general hypothesis that the evolution of novel caste types is driven by major shifts in ecological specialization, while the size distribution of existing castes tracks minor shifts in resource use.

Nomenclature

 *  CEPHALOTES [Myrmicinae: Cephalotini]
 * Cephalotes Latreille, 1802a: 357. Type-species: Formica atrata, by monotypy.
 * [Type-species not Formica cephalotes, unjustified subsequent designation by Wheeler, W.M. 1911f: 160; corrected by Wheeler, W.M. 1913a: 78.]
 * Cephalotes junior synonym of Cryptocerus: Fabricius, 1804: 419.
 * Cephalotes senior synonym of Cryptocerus: Wheeler, W.M. 1913a: 78; Smith, M.R. 1949c: 19; Kempf, 1951: 107.
 * Cephalotes senior synonym of Eucryptocerus, †Exocryptocerus, Zacryptocerus (and its junior synonyms Cyathocephalus, Cyathomyrmex, Harnedia, Hypocryptocerus, Paracryptocerus): De Andrade & Baroni Urbani, 1999: 59.
 * CRYPTOCERUS [junior synonym of Cephalotes]
 * Cryptocerus Latreille, 1803: 311. Type-species: Formica atrata, by subsequent designation of Latreille, 1810: 437.
 * [Type-species not Cryptocerus umbraculatus, unjustified subsequent designation by Emery, 1914c: 38; repeated in Emery, 1924d: 305.]
 * Cryptocerus junior synonym of Cephalotes: Wheeler, W.M. 1913a: 78; Smith, M.R. 1949c: 19; see also discussion in Kempf, 1951: 105. [Cephalotes and Cryptocerus share the same type-species, synonymy is therefore absolute.]
 * CYATHOMYRMEX [junior synonym of Cephalotes]
 * Cyathomyrmex Creighton, 1933: 100 [as subgenus of Cryptocerus]. Replacement name for Cyathocephalus Emery, above. [Junior homonym of Cyathocephalus Kessler, 1868: 135 (Cestoda).]
 * Cyathomyrmex subgenus of Paracryptocerus: Smith, M.R. 1949c: 21.
 * Cyathomyrmex junior synonym of Paracryptocerus: Kempf, 1972a: 175.
 * Cyathomyrmex junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * EUCRYPTOCERUS [junior synonym of Cephalotes]
 * Eucryptocerus Kempf, 1951: 127. Type-species: Cryptocerus oculatus, by original designation.
 * Eucryptocerus junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * †EXOCRYPTOCERUS [junior synonym of Cephalotes]
 * †Exocryptocerus Vierbergen & Scheven, 1995: 159. Type-species: †Exocryptocerus serratus, by original designation.
 * †Exocryptocerus junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * HARNEDIA [junior synonym of Cephalotes]
 * Harnedia Smith, M.R. 1949c: 20 [as subgenus of Paracryptocerus]. Type-species: Cryptocerus umbraculatus, by original designation.
 * Harnedia junior synonym of Paracryptocerus: Kempf, 1972a: 175.
 * Harnedia junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * HYPOCRYPTOCERUS [junior synonym of Cephalotes]
 * Hypocryptocerus Wheeler, W.M. 1920: 53 [as subgenus of Cryptocerus]. Type-species: Formica haemorrhoidalis, by original designation.
 * Hypocryptocerus raised to genus: Wheeler, W.M. 1936b: 200.
 * Hypocryptocerus junior synonym of Zacryptocerus: Kempf, 1973c: 460.
 * Hypocryptocerus junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * PARACRYPTOCERUS [junior synonym of Cephalotes]
 * Paracryptocerus Emery, 1915i: 192 [as subgenus of Cryptocerus]. Type-species: Cryptocerus spinosus, by original designation.
 * Paracryptocerus raised to genus: Smith, M.R. 1949c: 20; Kempf, 1951: 153.
 * Paracryptocerus senior synonym of Cyathocephalus (homonym), Cyathomyrmex, Harnedia: Kempf, 1972a: 175.
 * Paracryptocerus junior synonym of Zacryptocerus: Kempf, 1973c: 460.
 * Paracryptocerus junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.
 * ZACRYPTOCERUS [junior synonym of Cephalotes]
 * Zacryptocerus Wheeler, W.M. 1911f: 175 (see also footnote). Type-species: Cryptocerus clypeatus, by original designation.
 * [Zacryptocerus Ashmead, 1905b: 384. Nomen nudum. (Based on a non-existent type-species: Cryptocerus multistrigus. Nomen nudum, attributed to Smith, F.).]
 * Zacryptocerus senior synonym of Hypocryptocerus, Paracryptocerus (and its junior synonyms Cyathomyrmex, Cyathocephalus (homonym), Harnedia): Kempf, 1973c: 460.
 * Zacryptocerus junior synonym of Cephalotes: De Andrade & Baroni Urbani, 1999: 59.