why did they think anything would be "dead by now" and were caught off guard by the mosasaur and t-rex? the whole country is discussing whether to save the dinosaurs or let them die by the volcano, so obviously the jurassic world dinos were not dead yet at that point and they knew it.
sharethey can't write logical scripts anymore.
share1. The Mosasaurus was only fed by the Park, in a closed area. Once the fish (if there even were any) were killed, the dino couldn't eat anymore and would thus be died out. I don't know how it survived though, its not explained. But its perfectly reasonable to expect it would be dead after all that time.
2. The T-rex is old as fuck. This is the original T-rex from Jurassic Park 1. So it would also be reasonable to expect this dino to be either dead from old age or dead because the old girl got beaten by another younger dino. How is she still alive then? well, they explain it in the movie, when the guy asks wether the T-rex is dead or not. She then goes on to explain its possible under some circumstances that an animal lives longer than anticipated.
I guess Ingen (or whatever that corporation is called nowadays) just didn't care to investigate if the dangerous dinos are alive or not. They probably lied or just didn't know. One way or another, the guys going in didn't know or expected anything.