Enamel in the oral teeth of Latimeria chalumnae (Pisces: Actinistia): a scanning electron microscope study



An investigation with the scanning electron microscope into the microstructure of the surface layer covering the oral teeth of Latimeria chalumnae has shown this tissue to be enamel of the type found in amphibians, reptiles and mammals. It is not comparable with enameloid, cuticular enamel or terminal membrane enamel as described in scanning electron microscope accounts of the teeth of actinopterygians. Equidistant lamellations parallel to the enamel-dentine junction are a distinctive feature, interpreted in this study as phasic appositional growth, a characteristic of the ectodermal type of enamel. These conclusions together with those from histological and microradiographic studies confirm that enamel is present in coelacanths.

The microstructure of enamel in the teeth of Latimeria an extant actinistian compares well with that of fossil crossopterygian teeth described from polarized light studies and indicates that enamel, homologous with the ectodermal type of enamel is found in both actinistians and rhipidistians.