Original run: 1955-01-16 to 1955-03-27
Summary: Landing on Earth after their reluctant visit to a slave planet (S-051 Child Men and Giants), Flash and Dr. Zarkov suddenly find themselves confronted by prehistoric monsters from a world long gone by.
Unbeknown to the two baffled Earthmen, aliens from the distant star Antomni have set a plan in motion to colonise Earth by reversing the evolution of man and mutate its inhabitant to more controllable life fo rms...
(Source of summary: www.ipcomics.net)
All credits go to "spax".