The film opens up with "One Zillion BC - October 9th". This date of October 9th was John Lennon's birthday. This was in memory of this movie's lead star Ringo Starr's friend and former band-mate with The Beatles.
When showing at the old drive-in theaters in Australia every ticket holder was given a pamphlet with approximately 30 "caveman words" and an English translation for each word to listen for through the movie.
Before she met Ringo Starr and the two fell in love, Barbara Bach is on record as saying that she was originally disappointed that the lead part had gone to him instead of "a top comedian like Dudley Moore".
Jim Danforth, special effects designer of the stop-motion animated dinosaurs (the dinosaur and effects designer), apparently left the production of this movie about two-thirds of the way through because the Directors Guild of America allegedly disallowed his already contracted co-director credit alongside director Carl Gottlieb. Therefore, Danforth is not credited as a director on this picture, only for special effects and second unit director.