How would they have destroyed civilizations without a trace (not even iron/steel being left) without eradicating most animal and plant species at the same time?
All the choicest real estate of the time is under water now.
30+ genera of North American large animals were wiped out. Horses, camels, hippos, dire wolves, mammoths, mastodons, giant sloths, sabertooths, giant beavers. The whole continent burned. There were extinctions in South America and Africa, too.
Seems to me this could be the root of the Viking legends of Valhalla, the eternal hunting grounds, because at the time it existed it had to be one fucking fertile marshland.
All the choicest real estate of the time is under water now.
30+ genera of North American large animals were wiped out. Horses, camels, hippos, dire wolves, mammoths, mastodons, giant sloths, sabertooths, giant beavers. The whole continent burned. There were extinctions in South America and Africa, too.