... that there was a sentient and technological civilization derived from the Saurian species dominated on Earth over 65 million years ago.
The fossil record will always be incomplete or mislabeled. All evidence of an advanced civilization would be erased over time especially across 65 mya. Possibly, an artifact comprised of a unique metallic structure would unleash new insight on the long ago past.
That civilization could have developed space flight capability. In the future, manned missions to the Moon and Mars could uncover that Saurian colonization.
Furthermore, the colonists might have been the only survivors when the asteroid hit Earth 65 mya. They might have built generational ships and left the solar system. One day, they might return and find a bunch of mammals squatting on the planet.
Ot, they might be here already and are secretly behind the fast-food industry plus sweet food to fatten us up for future culinary needs.
Bon appetite!!!