4. Add the Face and Fin
Draw two humps along the back and tail to form the Ouranosaurus's fin. Make sure the top of the humps have ridges. Add the toenails on each of the four feet. Draw an oval for the eye and another for the ear. Don't forget the tear-drop shape for the nostril. Add a curved brow shape over the eye, and sketch the long lines for the mouth.
In the next section, we'll work on adding some skin features.