[Wendy Jackson Hall on Eric Leighton]: (About Dinosaur) A total of 48 animators worked on the film, one-third of who were already versed in computer animation, while the other two thirds came from traditional hand-drawn animation and stop-motion animation backgrounds. Early on, co-director Eric Leighton recruited several animators he knew from being a supervising animator on The Nightmare Before Christmas including Mike Belzer, Joel Fletcher, Angie Glocka, Owen Klatte and Trey Thomas.