It is may be so. History reveals Reptiles all over the place, in religions, carvings, paintings, etchings and more.
Imagine if they lived in underground cities far away from the peering eyes of humans, manipulating human kind as slaves to the needs of the rulers, the reptilians. How would they do it? Chameleon's change color, some reptiles can identify what color an object is 'in the dark' and can change to that color 'in the dark.'
Is it so impossible, or too far fetched to suspect that their may be shape shifter's out there, capable of altering their appearance.
How did the Sumerian race know there was 'water on the moons of Jupiter long before human kind ever knew there were moons around the planet?' Was another race exchanging intelligence and technologies with them?