Expert analysis suggests that the main prey of Osarasaurus was Tapuasaurus and Masakali thesaurus, not fish.

1. On the bones of Tapuasaurus and Masakali thesaurus, there are bite marks from the teeth of a Spinosaurus dinosaur suspected to be of the genus Osarasaurus.

2. There were very few fish species in Brazil at the same time

3. If you mainly rely on eating fish, it would be difficult to evolve to such a huge size

4 .A giant pure carnivore weighing more than 9 tons. If it mainly eats fish, it will be difficult to satisfy its appetite to survive.

5. Osarasaurus has binocular vision that is rare among carnivorous dinosaurs. If they were fish-eating animals rather than predators, it is difficult to explain why they evolved this kind of binocular vision. Fish-eating dinosaurs didn't need binocular vision to catch fish.