Pixar Animation is retooling The Good Dinosaur more than had been expected, according to one of its stars. The film explores what might have happened had dinosaurs had not become extinct and had to share the world with ancient humans.

Like all Pixar productions, The Good Dinosaur has weathered its fair share of production snafus. Pixar removed co-director Bob Peterson from the project, leading to Pixar laying off nearly 5% of its staff and postponing the film's release from 2014 to 2015. (For what it's worth, we liked what we saw of The Good Dinosaur at summer 2013's D23 Expo.)John Lithgow, who plays a dad dino opposite Frances McDormand's mom dino in the Pixar pic, revealed he has to totally redo his part in the film because of the changes being made to the film.“I recorded the entire role in Good Dinosaur. They have now dismantled it and completely reimagined it, and it is a fantastic new story," Lithgow told Collider . "So I’m gonna record again on it within the next month. Don’t worry. It’s coming and it’s gonna be better than I ever imagined.”The Good Dinosaur -- which made our list of 20 Upcoming Animated Movies We Can't Wait to See -- opens November 25, 2015.