[4] 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.

This was accomplished by performing comparative studies between four Cephalotes species, each representing one of the four character states of soldier evolution.

[5] Cephalotes was ideal for the study because it is the only genus to contain extant species displaying four levels of major morphological evolution.

[5] These character states are: Another study by Powell examined the process by which environmental factors shape colonial castes within the worker class.

All four genera were revised four years later by Maria De Andrade and Cesare Baroni Urbani (1999, who synonymized them under Cephalotes.