how do you figure that ? your not far off . i ' m just curious . <| sep |> the most plausible explanation doesn ' t involve humans 100 mya , but more that around 12 , 500 BC , there was a cataclysmic event involving a crust shift , causing massive coastal flooding which is backed up in multiple cultural historical myths ie . the deluge , noah ' s flood , gilgamesh ' s flood . The evidence is circumstantial , but it ' s plausible enough humans exist in modernish form for 100300 thousand years as hunter gatherers and then suddenly from 12 , 0004 , 000 BC , almost simultaneously , megalithic architecture , language , agriculture and a genetic population bottleneck pop up in various places , combined with the extinction of the neanderthals . and all before recorded history begins . and culturaltribal mythology in South America , China , Africa and Europe all suddenly include references to gods , sea peoples , flying machines and floods . I think it ' s plausible to say that an advanced naval society lived on Antarctica from 1512 , 000 BC and somewhere from 12 , 00010 , 000 BC you have a natural disaster that displaces them , at which point they scatter around the world , teaching various indigenous cultures how to build , how to farm , etc . regarded as godskings , though genetically they may not differ from the rest of society . but by the time the pyramids were built , it ' s probably long after this civilization had fallen and most likely some of the knowledgedescendants of the atlanteans built these structures to preserve the knowledge of this precursor race for the future , as around 4000 BC humanity was very fractured and warconquestlike otherwise why build a structure over a generation ? .