How I think Rebirth will conclude
So, given that the rumors of the Spinosaurus being labeled “Hero Dinosaur” seem to be true. I think we already have a pretty good idea of what the “final battle” will look like.
In the screenshot of Duncan luring the mutant with the flair, you can clearly see him splashing water. Which he looks to be already waist deep in. It’s not really clear if this is a river, lagoon, etc. but I think it shows that the water is deep enough for a couple of Spinosaurus to be hanging around.
As Duncan pushes further into the water, I have a feeling he’s going to run into our 3 thicc neck bois from the trailer. The Spinosaurus will likely roar and head over to eat him. But with the Mutant hot on his trail, the 3 Spinosaurus will quickly ignore him and prepare to defend themselves against the abomination. Duncan throws the flair towards the Spinosaurus, ducks for cover & Battle ensues. Maybe 1 or 2 of the Spinos will end up being taken down by the mutant, but in the end the Spinosaurus prevail and the humans get to run away freely.