When the Professor gives his talk to the Scientific Society, he uses the Piltdown Man in the progression "Chimp - Java Man - Piltdown Man - Cro-Magnon Man - Neanderthal Man - Modern Human." The Piltdown Man was a fake fossil that was comprehensively debunked in 1953, the same year that the film was released.
Robert Shayne finally got top billing in a film but, his name was misspelled as "Robert Shane" in the credits. His name was spelled properly on the poster and other promotional material.
This provided a rare top billed role for veteran character actor Robert Shayne. It came about during the same period that he got the role that would finally make him famous, Inspector Henderson on "The Adventures of Superman" (1952) television series.
When a saber-tooth tiger attacks George, the close-up image of the beast is a cheap stuffed animal with long teeth added in and whiskers drawn in. The image only appears for a second.
In the first bar scene when the hunter pours beer from the bottle to the glass, the beer is totally flat, no foam appears in the glass.