Cephalotes

Cephalotes is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall to the ground, which is often flooded.
Ecological specialization and evolution of a soldier caste
One of the most important aspects of the genus' social evolution and adaptation is the manner in which their social organization has been shaped by environmental pressures. This is particularly true of the species Cephalotes rohweri, in which an entire soldier class has evolved as a result of highly specialized nest cavity availability.
Because ants within Cephalotes use multiple carved nesting cavities found in the trees upon which they live, a cohort of morphologically specialized soldiers has evolved to defend these nesting cavities. They use their unique plate-like heads to block the entrances to the nests, essentially creating a living door to the nest cavities.
In one particular study, Scott Powell tested the hypothesis that "specialized use of cavities with entrances close to the area of one ant head has selected for a morphologically and behaviorally specialized soldier in Cephalotes." This was accomplished by performing comparative studies between four Cephalotes species, each representing one of the four character states of soldier evolution. Cephalotes was ideal for the study because it is the only genus to contain extant species displaying four levels of major morphological evolution. These character states are:
No soldier present (ancestral)
Soldiers present with simple domed head
Soldiers present with incomplete head-disk
Soldiers present with complete head disk (most advanced)
Another study by Powell examined the process by which environmental factors shape colonial castes within the worker class. However, this study focused more on how colonies adapt their caste systems to ecological factors in their environment.
For the experiment, a species of the genus Cephalotes was used that displayed the highest level of soldier specialization. Three key findings regarding adaptive caste specialization were supported:
Soldiers were best at defending the specific nesting resource found in nature.
Colonies used only certain nests (out of all the available nests), and selected only the nesting sites that would maximize soldier performance.
Soldier performance and limitations had both direct and indirect effects on colony reproduction.
The results of this experiment support the concept that the most specialized soldier phenotype in Cephalotes is a result of adaptation to ecological specialization within a narrow subset of available nests.
Species
Cephalotes adolphi
Cephalotes alfaroi
Cephalotes angustus
Cephalotes argentatus
Cephalotes argentiventris
Cephalotes atratus
Cephalotes auriger
Cephalotes basalis
Cephalotes betoi
Cephalotes biguttatus
Cephalotes bimaculatus
Cephalotes bivestitus
Cephalotes bohlsi
Cephalotes borgmeieri
Cephalotes bruchi
Cephalotes chacmul
Cephalotes christopherseni
Cephalotes clypeatus
Cephalotes coffeae
Cephalotes columbicus
Cephalotes complanatus
Cephalotes conspersus
Cephalotes cordatus
Cephalotes cordiae
Cephalotes cordiventris
Cephalotes crenaticeps
Cephalotes cristatus
Cephalotes curvistriatus
Cephalotes decolor
Cephalotes decoloratus
Cephalotes dentidorsum
Cephalotes depressus
Cephalotes dorbignyanus
Cephalotes duckei
Cephalotes ecuadorialis
Cephalotes eduarduli
Cephalotes emeryi
Cephalotes fiebrigi
Cephalotes flavigaster
Cephalotes foliaceus
Cephalotes fossithorax
Cephalotes frigidus
Cephalotes gabicamacho
Cephalotes goeldii
Cephalotes goniodontes
Cephalotes grandinosus
Cephalotes guayaki
Cephalotes haemorrhoidalis
Cephalotes hamulus
Cephalotes hirsutus
Cephalotes inaequalis
Cephalotes inca
Cephalotes incertus
Cephalotes insularis
Cephalotes jamaicensis
Cephalotes jheringi
Cephalotes klugi
Cephalotes kukulcan
Cephalotes laminatus
Cephalotes lanuginosus
Cephalotes lenca
Cephalotes liepini
Cephalotes liogaster
Cephalotes liviaprado
Cephalotes maculatus
Cephalotes manni
Cephalotes marginatus
Cephalotes mariadeandrade
Cephalotes marycorn
Cephalotes membranaceus
Cephalotes minutus
Cephalotes mompox
Cephalotes monicaulyssea
Cephalotes multispinosus
Cephalotes nilpiei
Cephalotes notatus
Cephalotes oculatus
Cephalotes opacus
Cephalotes pallens
Cephalotes pallidicephalus
Cephalotes pallidoides
Cephalotes pallidus
Cephalotes palta
Cephalotes palustris
Cephalotes patei
Cephalotes patellaris
Cephalotes pavonii
Cephalotes pellans
Cephalotes persimilis
Cephalotes persimplex
Cephalotes peruviensis
Cephalotes pileini
Cephalotes pilosus
Cephalotes pinelii
Cephalotes placidus
Cephalotes porrasi
Cephalotes prodigiosus
Cephalotes pusillus
Cephalotes quadratus
Cephalotes ramiphilus
Cephalotes rohweri
Cephalotes scutulatus
Cephalotes serraticeps
Cephalotes setulifer
Cephalotes simillimus
Cephalotes sobrius
Cephalotes solidus
Cephalotes specularis
Cephalotes spinosus
Cephalotes supercilii
Cephalotes targionii
Cephalotes texanus
Cephalotes toltecus
Cephalotes trichophorus
Cephalotes umbraculatus
Cephalotes unimaculatus
Cephalotes ustus
Cephalotes varians
Cephalotes vinosus
Cephalotes wheeleri
Fossil species
The fossil record is restricted to the Miocene with species recovered from both Dominican and Mexican ambers. Species were initially described by Gijsbertus Vierbergen and Joachim Scheven (1995) whole placed the species into the genera Cephalotes, Eucryptocerus, Exocryptocerus and Zacryptocerus. All four genera were revised four years later by Maria De Andrade and Cesare Baroni Urbani (1999, who synonymized them under Cephalotes.
The Dominican amber species:
†Cephalotes alveolatus
†Cephalotes bloosi
†Cephalotes brevispineus
†Cephalotes caribicus
†Cephalotes dieteri
†Cephalotes hispaniolicus
†Cephalotes integerrimus
†Cephalotes jansei
†Cephalotes obscurus
†Cephalotes resinae
†Cephalotes serratus
†Cephalotes squamosus
†Cephalotes sucinus
†Cephalotes taino
The Mexican amber species:
†Cephalotes maya
†Cephalotes olmecus
†Cephalotes poinari
†Cephalotes ventriosus
See also
Aphantochilus, a genus of crab spiders known to mimic Cephalotes species
References
External links
Myrmicinae
Ant genera