Well, first of all, make sure you have DD activated.
Then, we can proceed:
-Select Boreal forest, and paint the exibit with trees, plants and rocks activated.
-After you have done it, paint the exibit with tropical rain forest dirt. Looks better with
Aim's terrain pack version.
-Place the combination of dinos you want. All species will be with a bit of green. Personally, I think Carnotaurus/Tyrannosaurus and Triceratops/Styracosaurus.
Pics of how does it look like: