According to Deadline, the original cast of The Good Dinosaur has now gone the way of the dinosaurs, with the exception of McDormand. Raymond Ochoa replaces Neff as Arlo the Apatosaurus. Jeffrey Wright plays Poppa, Arlo's father; McDormand remains as Arlo's mother, Momma; Anna Paquin is Ramsey the T-Rex; Sam Elliott as a T-Rex named Butch; Steve Zahn voices Thunderclap the pterodactyl; AJ Buckley is a T-Rex named Nash; Jack Bright voices Arlo's human companion, Spot; and Marcus Scribner voices Arlo's brother, Buck. The screenplay has been altered enough that Arlo's three siblings have now been condensed into just one.
Even with all of these changes, Pixar still plans to have The Good Dinosaur ready by November 25th.