Figure 15A. Some representative fossils with scleral ossicles. A-D demonstrate that scleral ossicles were widespread throughout the Dinosauria; E-G demonstrate their existence in pliosaurs, mosasaurs and ichthyosaurs as well. Although none are shown here, scleral ossicles also existed in the eyes of pterosaurs; H shows the scleral "ossicles" of a Late Devonian placoderm. Whether or not the ossicles of fish were and are homologous or even functionally similar to those of reptiles remains to be resolved. Dunkleosteus, like actinopterygian fish, contained only four ossicles per eye. Reptiles generally have 14. (Photographs courtesy of K. Carpenter except for Tylosaurus which was supplied by M. Everhart, see Figure 15B.).