"tyrannosaurus rex" was one of the first dinosaurs the development team began working on. for the "t. rex" roars, the game's sound team obtained audio samples from the films and then altered them for originality. the animation team then altered their "t. rex" roaring animations to fit the sound effects. to design the dinosaurs the development team primarily referred to the films for consistency, while incorporating some of the latest scientific discoveries to add to their designs. the team also studied birds and other animals to aid in designing the dinosaurs. in addition to their designs, dinosaur behavior was based on a combination of the films and scientific findings. paleontologist jack horner, who served as an advisor on the films, was also consulted for advice on the game's dinosaurs. they were given bright and colorful hides based on new dinosaur research.