Moon Landing, Machines in Moon, Ancient Egypt, Mars, Elongated Skull People
Additional note on the sentience discussion: Sentience is a *gift* that comes from a single source. In other words, sentience is not achieved, but rather granted. This change or upgrade being instant would also explain why no ‘transitory’ species have ever been found–only pre-sentient and post-sentient variations. More can be found on this fascinating topic in the book, Of People and Pandas.
Drowning in absurdity 