Cephalotes

Common in the New World tropics, Turtle 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. Nests occupy pre-existing arboreal cavities, and soldiers function as living doors to admit incoming foragers or exclude potential intruders.

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

Identification
De Andrade and Baroni Urbani (1999) assigned Cephalotes species to clades.

Fossils
Fossils are known from:,.

Castes
Powell (2016) studied how nesting ecology in Cephalotes has shaped the diversification of an elaborate soldier caste. The evolution of morphologically specialized soldier heads was associated with substantial shifts in nest-entrance preferences, and in many species there is a match between head sizes and entrance sizes. 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

 * ''[Note: traditionally, major workers in this predominantly worker-dimorphic genus are termed “soldiers”, and minor workers “workers” (e.g. Kempf, 1951, De Andrade & Baroni Urbani, 1999). This terminology is maintained here, while recognising that the term “soldier” refers only to size/morphology, not to the function of the caste.]