Despite their significant differences and specializations, ectodermal appendages (hairs, scales or feathers) are the result of identical developmental processes. This same phenomenon applies to the dental classes in bats, which have four types of teeth, major morphological innovation of mammals, whose morphology is highly specific to the species’ diet. The aim of my thesis is to study the origin and diversification of tooth classes from genotype to phenotype in Noctilionoid. This project will combine a transcriptomic, morphological and developmental biology approach. The results will shed new light on the origin of tooth classes in mammals since it has been studied until now mainly from a morphological point of view.