Dentition Size and Tooth Number

Among hominoids, extant human dentition is of a reduced size. However, extinct species show different patterns. Early in their evolution and in contrast with other apes, hominins displayed small canines with a low level of sexual dimorphism. This is often explained by changes in their socio-sexual behaviour, and in particular with a reduced intensity of intrasexual agonistic competition. Late representatives of the genus Australopithecus displayed large molars and premolars and reduced anterior teeth. This pattern, which is likely related to specific diet adaptations, is even more spectacular in Paranthropus. In this genus, premolars are molarized and anterior teeth extremely reduced. Post-canine dentition did not significantly decrease in size before the emergence of the genus Homo ca. 2.4 Ma. The first representatives of the genus Homo displayed relatively large anterior dentition and reduced cheek teeth. This is usually interpreted as the result of an increase in carnivory levels. Overall, the dentition reduces over the course of evolution of the genus Homo in relation to the development of artifacts and food preparation. Late Homo displayed a more or less marked reduction of the posterior dentition. In recent Homo sapiens, the last molar can be vestigial or absent.