Why Did the Strepsirhine Tooth Comb Evolve?

Abstract

The hypothesis that the original strepsirhine tooth comb evolved for scraping gum is examined. The comparative morphology of the anterior dentition does not corroborate this view, and our study suggests that the primitive tooth comb, which was 6-toothed, evolved for the maintenance of the five, evenly distributed narrow spaces in between them. Unlike the incisors of other groups, platyrrhines or catarrhines, for example, the apical extremities in the primitive condition are not closer to one another than the basal portions of these teeth. The biological role responsible for the evolution of the function of the original tooth comb is believed to be fur-combing. Subsequent modifications in numerous lineages altered both morphology and function as a result of new roles, and this tended to obscure the cause of origin of this character complex.