Dinosaurs are terrestrial creatures, not marine creatures, so there is no such thing as "undersea dinosaurs". However, there were indeed some giant reptiles in the ancient oceans, such as plesiosaurs and ceratosaurus, which were considered to be the top predators in the oceans at that time. Here are the top ten reptiles that may have been the overlords of the ancient ocean:
1. Plesiosaur
2. Earthworm Dragon
3. Spinosaurus
4. Spinosaurus
5. Mossia
6. Megalodon
7. Hippocampus
8. Diplodocus
9. Sauropod Sea Dragons
10. Tylosaurus
It should be noted that not all of these reptiles lived in the same time period or the same area, and their status may be controversial.
