Erm, wasn\'t the real experiments based on Jurassic Park. There probably were some preliminary experiments done - which is where Michael Crichton got his idea from.. but no-one actually took the idea seriously until after Chrichton\'s book provided a plausable scenario for it happening.. and of course the movie which gained public attention and thus helped the grant money flow a lil.
And ViVi.. erm.. I\'m no Biology teacher, but from all I\'ve read our atmosphere hasn\'t changed that drastically in quite some time. I mean.. what would cause the oxygen to rise up to such a drastic level as it is now? The last time that really happened was way before the dinosaurs when our atmosphere consisted mostly of Carbon Dioxide.. this is the time when plants first started appearing in the form of algie and mosses. Accustomed to the enviroment at the time, they thrived on Carbon Dioxide.. but expelled Oxygen as a waste product. With the rapid explosion of plant life.. Oxygen levels rose gradually and killed off most of the life forms which couldn\'t adapt. (Oxygen is actually a very deadly gas). All of this happened over a billion years before the Dinosaurs appeared, back when life was still mainly multi-celular with basic fish and crustations just beginning to appear.
As for their diets.. it all really just breaks down to vitamins and minerals. I\'m sure we could find a substitute or create a hybrid plant which they\'ll eat to sustain them given enough time and experimentation.