In Descent 1: 26, CD commented that posterior molar or wisdom teeth seemed to be becoming rudimentary in ‘the more civilised races’ of humans, possibly owing to a change in diet, and that these teeth were smaller than the other molars in humans, chimpanzees, and orang-utans. Marmosets belong to the family Callitrichidae, the members of which have one fewer molar on each side of both jaws than most other primates (Nowak 1999).