Not to mention human impact and our decimation of the natural resources of the planet. Obviously in our small numbers, we did not kill off these guys, but even today species are dying out because of our destructive nature. We're not killing them with kindness.

I kind of hold with the idea that mega-fauna still exists in Africa because there it co-evolved with humans and was able to adjust to how humans changed environments.

@snytiger6 I would maintain that it continues to exist (1) because the ice age did not affect africa as much as the rest of the planet (2) destructive technology isn't as rampant in the african nations.

@TheoryNumber3 I doubt it there is any one or just a few reasons, but it does appears that man does contribute largely to influence extinctions.