Linked from
The 19 pages that link to Megafauna, each with the reason it gives.
Mammoth SteppeNarrower topic: The steppe’s ecology depended on unusually abundant large herbivores.
AurochsNarrower topic: Aurochs were major herbivores within ancient landscapes.
ToxodonNarrower topic: Toxodon was among South America’s conspicuous Pleistocene megafauna.
MegalonyxNarrower topic: Megalonyx was part of North America’s extinct Pleistocene megafauna.
SthenurusNarrower topic: Sthenurus was part of Australia’s Pleistocene large-animal fauna.