Joe Johnston had been interested in directing the sequel to Jurassic Park and approached friend Steven Spielberg about the project. While Spielberg wanted to direct the first sequel, he agreed that if there was ever a third film, Johnston could direct.[3] The third film was greenlit in August 1999 and was based on a story by Steven Spielberg, featuring Alan Grant after having lived in a tree on one of the islands and studied the dinosaur population. Johnston never had any concrete concept for the third installment, other than stating the film would be "more stand-alone" and feature a lot of flying reptiles.[4] Before that, Craig Rosenberg wrote a script involving teenagers who get marooned on Isla Sorna.[5]
New writers were brought in to scribe a story involving Pteranodon escaping from Site B and causing a rash of mysterious killings on the mainland, which was to be investigated by Alan Grant and a number of other characters including wealthy Paul Roby and his teenage son Miles, Paul's love interest, Billy Brennan, a naturalist named Simone, and a tough Military Attache. Grant's group was to track the Pterosaurs back to Site B and crash on the island, while a parallel investigation was carried out on the mainland. Supposedly, the aviary sequence and laboratory set piece were much longer and more complex, including raptors stealthily entering the hatchery while the team spent the night. Sets, costumes, and props were built for this version, before Johnston threw out the completed script five weeks before filming in order to pursue the "rescue mission" plot, which was suggested by David Koepp.[3] Johnston said that the script was never finished during production - "We shot pages that eventually went into the final script but we didn't have a document".[5]
