To tame a ceratosaurus you must have a hemoglobin cocktail (I think that’s what it’s called). Use a tanky dinosaur (like a stego) and have prime meat

1. Make a cocktail and find a ceratosaurus

2. Feed cocktail to a tanky dinosaur (must be tamed) and whistle it on passive. (Tip: double check it’s on passive)

3. Lure the cerato over and have it attack the dinosaur which consumed the cocktail

4.the cerato should be glowing dark pink

5. Above the cerato, it will say a percentage drunk. When this reaches 100 feed prime meat until tamed