Figure 3 in Paleohistological studies of bone and teeth in Gyrodus circularis (Gyrodidae: Pycnodontiformes: Actinopterygii). Phylogenetic implications for the Gyrodidae

Figure 3. – Gyrodus circularis. (MNHN. JRE 540). Axial ground section (MNHN-F-Histos 2743). Detail of the crown of teeth No 1. The two parts of the dentine core are clearly seen: the circumpulpar orthodentine (od) with its fine laminations (arrowheads) and the upper thick layer of acrodine (ac) that is crossed by the odontoblastic canalicles that progressively get thinner and stop before the surface of the crown (arrow). The black pigmentation is restricted to the more external acrodine layer. The spheritic dentine (sd) is clearly seen at the top of the pulp cavity (pc). Scale bar = 10 μm.