In the film, actors provide voiceovers for the main creatures. Director Barry Cook said the original plan was for the film to be without dialogue or narration. He said, "I think originally, we were looking at a film that could stand alone as a virtual silent movie... You can turn the soundtrack off and still get involved with the story and feel the emotions of the characters. In its final version, the movie has a narration and goes inside the heads of the animals, so you can hear what they're thinking."[13] Executives at 20th Century Fox, one of the film's main distributors, viewed a rough cut and thought the film needed voiceovers so children in the audience could connect to the characters.[31]
The film's character designer David Krentz said, "Although the production veered away from being very realistic, the animation still plays independently. The powers that be decided to add narration and voice-over to reach a wider audience and the characters became slightly anthropomorphized to make them more attractive to younger kids."[13] Palaeontologist Steve Brusatte responded to The Scotsman's prompt about the "danger of anthropomorphising" the dinosaurs, "The voiceovers are a bit of a compromise; the dinosaurs' lips aren't moving, they are not smiling and having human-like facial expressions or anything like that... They are only anthropomorphised to a small degree and that is necessary for a film like this."[22]

"When you select "Cretaceous Cut" from the Extras menu, there's a secondary menu that pops up where you can choose either 3D or 2D. If you don't have a 3D display connected to your player, you may not get that option--that's how other similarly authored discs work."