David Allen created this as a pitch reel to generate interest in his magnum opus, the long belated feature film The Primevals (2023).
Hammer Films created a poster and announced the film as forthcoming in 1969 under the title "Zeppelin v. Pterodactyls." In 2007, Robert T. Northrup made a film with this title, which was stitched together with clips from public domain serials. In 2017, another adaptation was created for a live stage reading at the Mayhem Film Festival.
The film was framed in flashback, with one gentleman (who kept the hand of a lizard man in his desk drawer) telling the story to his friends. The actors who appeared in this segment were recruited from a Hollywood repertory theater, and their names have been lost to time.
In this version of the story, there was no explanation for the reptilian people. When David Allen revised the plot for his feature film The Primevals (2023), he decides to make them an ancient race of extraterrestrials.
The story was conceived and preliminary work began in 1967, but the live-action portion wasn't shot until the following year.