Yes, the above painting is a bit graphic, but please imagine an infestation of mastodons. That's right.
Having driven so many megafauna to the edge of extinction, it's hard for humans to fathom the destructive possibilities here, but as a fascinating new paper from the Proceedings of the National Academy of Sciences explains, mammoths, mastodons and giant ground sloths could have easily devastated the late Pleistocene environment with their ravenous hunger.
Luckily, "hypercarnivores" were there to keep their numbers in check. We're talking packs of hulking smilodons and hyenas, each double the size of their modern-day kin. The Duke University study used mathematical, fossil-based models to plot out the size of late Pleistocene predators and prey, concluding that cave hyenas could have taken down a 2-ton juvenile mastodons. As the disturbing smilodon illustration suggests, this would have been the primary means by which hypercarnivores kept megafauna numbers down.
Modern elephants are largely immune to non-human predation, and it would have been much the same 15,000 years ago. But as study authors V. Louise Roth and Blaire Van Valkenburgh point out, lions still occasionally snare a juvenile African elephant via a coordinated attack. Predators of the late Pleistocene may have benefited from both larger individual size and larger pack size, further-enabling such population-curbing victories.
Such horror was the price of ecological balance, it seems.