I can't answer the when does it open part but we have been to the one in KC and my son who was 4 at the time LOVED it ... we will be going back to KC the 1st week in June and plan to go again.
the menu is alot like Rainforest (but no Turkey wrap I had hoped they would have that its what I get at rainforest every time) if it is like the KC one there will be a fun gift shop with a Build a Dino (build a bear company but all different dinosaurs to make) and fun things liek geodes you can buy and break open the food was pretty good