Jack Horner was a consultant, and the artwork of Gregory Paul, Mark Hallett, Doug Henderson, and John Gurche were used in pre-production. While the dinosaurs eventually shown in the films had various anatomical inaccuracies, all four of these artists are in the on-screen credits as "Dinosaur Specialists".
Jack Horner was a consultant for the film, and the artwork of Gregory Paul, Mark Hallett, Doug Henderson, and John Gurche were used during pre-production to create the dinosaurs in the movie. Despite the inaccuracies in the dinosaur designs, all four artists are credited as "Dinosaur Specialists" on screen.