Some people, usually fans of alternative history, have embraced a thought experiment called

the Silurian hypothesis, which offers the possibility that a pre-human civilization may have evolved

on Earth.

It could have grown, become intelligent, manipulated its environment with technology,

and perhaps even surpassed

human technology, until falling victim to some global cataclysm.

And all of this, hundreds of millions of years prior to what we now regard as the first

animal life.

The reason we can't disprove this, according to the hypothesis, is that geological processes could have wiped away all paleontological evidence of their existence.

And in our extended content for premium members, a deeper dive into the most densely packed second on the 24-hour analogy of Earth's history.

All of that and more is coming up right now on Skeptoid.

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