Okay, I will decide.
There was indeed a prehistoric underwater city founded by salt water marine animals.
They were seriously working on an underwater hand axe. And they developed many prototypes.
These civilized marine animals were wiped out when too many Africans went to South Africa and the continent tipped their city up out of the water.
They dried out, got sand blased, and the rest is history.
Who lives in a pineapple under the sea?