The special effects were so good that footage from this film was used in numerous other pictures produced well into the 1960s.
When the film was released in Britain, it was heavily edited due to their strict laws against animal cruelty.
The #1 box-office attraction of 1940 (excluding the roll-over receipts for Autant en emporte le vent (1939)).
In the remake Un million d'années avant J.C. (1966), Robert Brown wore identical make-up when playing Akhoba to that worn by Lon Chaney Jr. in this film.
In order to get the lizards to move, heaters had to be turned on full blast because reptiles don't move in cold weather.