"The Natural History Project" was the working title for a feature film about dinosaurs conceived by Jim Henson in 1986 as his next big fantasy feature. Following the visually sophisticated style set by The Dark Crystal and Labyrinth, the film would feature groundbreaking special effects by the Jim Henson Creature Shop.
William Stout was hired by Henson to write the screenplay and design the artistic world of the film. The film would be produced by Jim Henson and his daughter Lisa, and would be directed by Jim. Warner Brothers was enthusiastic about teaming up with Henson on the project, and committed a budget of $25 million for production, plus $5 million for character research and development.
The story involved a gruff old parasaurolophus who serves as a guide and teacher to a young corythosaur named Cory. Sketches also exist for a pair of dim-witted pachycephalosaurs, a "woeful" ankylosaur, a "haughty" styracosaur and a trio of villainous velociraptors to provide comical relief for the film's villainous monster, a Tyrannosaurus rex.
However, almost a year after the script had been approved and pre-production design work had been completed, production halted. The studio decided to hold off on the project when it was discovered that another dinosaur film, The Land Before Time, was in production by Universal Pictures.
|“||The project got cancelled because they found out that Lucas and Spielberg were doing a very similar project called The Land Before Time, ironically written by the people who wrote the last Muppets movie [Tony Geiss and Judy Freudberg, who wrote Follow That Bird]. It was very frustrating, depressing. I considered my Henson script as my best screenplay ever; it was a highly personal project for me. I was really excited about seeing it on the screen. To add even more irony, later I got hired to do some of the advertising for The Land Before Time.||”|
- -William Stout 
The film had been gathering dust on the shelf until Stout bumped into Henson during a visit at Walt Disney Imagineering in May 1990. Stout was informed that work could resume on the project in two weeks, but Henson passed away only days later. 
When the Henson sitcom Dinosaurs premiered in April, 1991, news articles about the show highlighted the connection to Jim Henson, who had died the year before. "Jim Henson dreamed up the show's basic concept about three years ago," said a New York Times article in April, 1991. "'He wanted it to be a sitcom with a pretty standard structure, with the biggest differences being that it's a family of dinosaurs and their society has this strange toxic life style,' said Brian Henson. But until The Simpsons took off, said Alex Rockwell, a vice president of the Henson organization, 'people thought it was a crazy idea.'"  A 1993 article in The New Yorker said that Henson continued to work on a dinosaur project until the "last months of his life." 
These dates correspond to the period when Henson and Stout were working on The Natural History Project, and it is possible that their work on the film inspired the animatronic dinosaurs of the TV show.
The images on this page are conceptual drawings by William Stout, taken from the 1996 William Stout: Saurians & Sorcerers collector's card set.