Deleted Scene: A scene in which Screweyes cages and chains the dinosaurs, explains how he lost his eye, and blasts Brain Drain down their throats with actual cannons was fully animated, but cut from the film. Bits and pieces of it can still be found.
Hey, It's That Voice!: John Goodman, Jay Leno, Walter Cronkite, Kenneth Mars, Julia Child, Martin Short, Larry King, and Yeardley Smith (aka Lisa Simpson) - plus, for British viewers, Felicity Kendal (in one of her very few film roles, live-action or animated). Cecilia's voice is pretty much exactly the same as Smith's Lisa Simpson. At least Leno doesn't sound like Leno.
Incidentally, while Leno and King seemingly turn up in any movie that'll have them, this was Cronkite's only feature film.
The Other Marty: John Malkovich was originally cast as Screweyes but left due to constant script rewrites (the film's Executive Meddling also caused him to leave Hollywood and only do international productions for a few years).