Fig. 4. Mixosaurid ichthyosaur Mixosaurus cornalianus Bassani, 1886 in New findings reveal that the Middle Triassic ichthyosaur Mixosaurus cornalianus is the oldest amniote with a dorsal fin

Fig. 4. Mixosaurid ichthyosaur Mixosaurus cornalianus Bassani, 1886 (BES SC 1000), Sasso Caldo quarry, Besano, Italy, upper Anisian. A. General view of the specimen showing the position of the dorsal fin (black arrow) and of the dorsal lobe of the caudal fin (white arrow). B. Explanatory drawing showing the position of the dorsal fin (dark grey), skin remains (grey), and neural spines (light grey). C. Close up of the shaft of the dorsal fin showing parallel fibres. D. Dorsal lobe of the caudal fin. E, F. Close ups of the areas of the dorsal lobe of the caudal fin where other fibres and skin remains are exposed.