It is interesting to note that, in the 26-year partnership between producer Charles H. Schneer and special effects artist Ray Harryhausen (which had just begun the previous year at Columbia Pictures with It Came from Beneath the Sea (1955)), "The Animal World" is one of just two films (the other being One Million Years B.C. (1966)) of Harryhausen's work during that time frame that Schneer did not produce.
This film contains the first color work of stop-motion animator Ray Harryhausen in a feature film. This was also the second and last time he worked under his mentor, Willis H. O'Brien, who supervised the stop-motion animation in this film. (The first was Mighty Joe Young (1949).)
For many years, this was regarded as a lost film with no surviving prints, or pre-print material, of the complete version. Warner Bros. since discovered, restored, and released a complete version as part of its Warner Archive series.
In interviews following his retirement, Ray Harryhausen indicated the film "ran into a censorship problem" apparently from the Hays Office. The criticism centered on the sequence of a Ceratosaurus killing a Stegosaurus, and then fighting a second Ceratosaurus. The criticism centered on the violence of the fight sequence. Harryhausen noted the film's live action animal sequences were similarly bloody, hence the viciousness of the dinosaur battle.