[btilly]

There have been many interglacials and only in one did the megafauna die out en masse. This is a good argument against it simply being from climate change.

Instead look to what was different in the most recent one. A weird species on 2 feet with hunting techniques that the megafauna had never encountered before. Such as using fire to drive whole herds of horses off of a cliff.

[ncmncm]

Not plausible. Humans at much higher density had been able to drive island populations to extinction, but had not succeeded on a continent. Furthermore, they had been in the Americas for many millennia already.

Horses and camels were all over Asia, coeval with humans, and did fine. Lions survived in in Europe well into recorded history. Africa, of course, retained about everything for hundreds of millennia, except for 3 genera right at 12800 years ago. The only notable extinction in Eurasia was the woolly mammoth, which survived only on Wrangel Island. Humans had been in the Americas for many millennia, but populations of these animals did not decline during that time.

Instead, the 30+ genera and the Clovis people all vanished at identically the same time, coincident with the layer of radically elevated platinum dust, shocked quartz, and soot.