 Despite the title of the film referencing the Jurassic period , Brachiosaurus and Dilophosaurus are the only dinosaurs featured that actually lived during that time ; the other species featured did not exist until the Cretaceous period . This is acknowledged in the film during a scene where Dr. Grant describes the ferocity of the Velociraptor to a young boy , saying " Try to imagine yourself in the Cretaceous period ... " 
