Its hard to tell from that picture but I can say having worked at Dinosaur, that those trees are planted on the roof of the building. The area they are in is above the hallway after the preshow. Also, under that are a bunch of training rooms, offices and bathrooms. When you enter Dinosaur, you are on level two. They just did a good job covering up the building so it looks real, but from the ground in between, you can easily tell that it is all one structure.