Well, maybe it's not supposed to be that dark. But it does give the scene a creepy mood that I like better and helps make the T-Rex more real. When brighten, you see just by looking at his feet that it's fake.

Anyway, when starting with the 2D Blu-ray :

... and matching it to the 3D Blu-ray :

... I obtain this :

So it is possible to have a Jurassic Park with better colors and not DNRed like hell. It's still darker than the 2D, but less than the 35mm scan... and unfortunately the feet reveal the phony business.