Micromammals molars (magnified models)

Rodents, of which some representatives are on display (dormouse, black rat and water vole), have large molars, whose surface is roughened by the presence of two alternate materials: enamel lamellae protrude slightly between depressions resulting from the wearing out of dentine, which, being weaker, gets abraded faster maintaining the roughness of the tooth. This structure allows rodents to feed on fibrous and tough plants, which can be digested only after having been effectively grounded. Molars of this kind have evolved also in other groups of mammals, like ungulates and elephants (made by R. Miolo).