The very real probability that non-human intelligences visited and even copulated with primordial humans is detailed in civilization's most ancient cultural and religious records. These historical records further reveal that these intelligences were reptilian in nature--or, at the very least, have been represented throughout human history in reptilian form.
From the Serpent, Nachash, in the Garden of Eden; Atum, the Egyptian snake-man; and Quetzalcotl, the feathered serpent god of the Mayans to the double-helix snake symbol of Enki/Ea in ancient Sumerian literature, the serpent has been the omnipresent link between humans and the gods in every culture.