The idea here is that humanity had started forming true civilizations before 10,000 BC, and a comet impact or airburst over one of the ice sheets caused a huge fireball and flood that led to mass extinctions and the annihilation of civilization
There’s no mystery about what caused the quaternary mass extinction—humans reached the Americas and wiped out the ecologically naive megafauna.
There’s no mystery about what caused the quaternary mass extinction—humans reached the Americas and wiped out the ecologically naive megafauna.