February 2, 2018
We assume that we are the dominant species, or at least the rulers of this planet. But I would suggest that between under water, and underground, there is more than enough room for another species. We know more about space than either.
To come from either place, or to have been inhabiting them long enough,they negate your mcc problem.
I would submit that a subterranean reptile species has been here longer than us. They farm the surface, and stay out of sight, by travelling underwater mostly.
It's better to walk alone, than with a crowd going in the wrong direction. H.S.