ABSTRACT
Biological hard tissue structures can only be fully comprehended through a thorough understanding of developmental mechanisms. This is possible to achieve by studying living animals. We limit our coverage here to dental tissues in extant mammals. We describe mammalian tooth germs, the embryonic origins of dentine, enamel and cementum and the basics of tooth form. We explore the histology of dental tissues in respect to variability in cell behaviors, matrix and mineralization strategies, their periodic and sometimes aperiodic growth expression and the adaptive structural patterns that emerge. We also relay the advantages and pitfalls of preparation and imaging methods particularly useful to the paleohistologist. We are particularly focused on the sophisticated heterodont dentitions of mammals among the gnathostomes. Yet, the diversity explored here is expected to be a vast underestimation of the real variability among living and extinct mammals.
