This Ends Now...

As a mammal paleontology enthusiast, I have come across numerous reconstructions of prehistoric mammals. However, one particular group is always reconstructed the same way. The ground sloths are always portrayed as omnivorous opportunists, feeding on leaves and plant matter, but also eating meat and carrion as well.

The entire idea that ground sloths could have eaten meat comes from a single paper entitled “Megatherium, the stabber”. In it, the scientists suggest that Megatherium and its ground sloth kin were carnivorous superpredators, on the sole basis that the muscles of Megatherium were strongly anchored, and could thus move fast.

This claim is rather dumb. While being able to move an react fast does mean Megatherium was bad-ass, it doesn’t make it a carnivore. We know that ground sloths were more energetic than their slow, tree-climbing kin today, so it makes sense that they could react and move faster. In short, if you tick a Megatherium or an Eremotherium off, it will take your head off in a second. By the same idea that is claimed here, because pronghorn can run very fast, they must chase down prey. Or, because peccaries have big, nasty teeth, they use them to hunt and kill other animals.

Enter exhibit two, the teeth. The teeth of ground sloths are dull, flat, and horribly unsuited for meat consumption. Most carnivorous or omnivorous animals have somewhat pointed teeth, for tearing off consumable chunks of flesh. But ground sloths don’t have even the closest semblance to these, and their teeth actually resemble dull molars more than ripping canines and incisors.

Still aren’t convinced? Well, here’s the final nail in the coffin. In the deserts of the Southwest United States, desiccated sloth dung has been found; specifically from the genus Nothrotheriops, a close cousin to Megatherium and Eremotherium. This dung is not fossilized, just dried out, and scientists have analyzed it to find out what sloths ate. The dung had no animal matter in it, just vegetation; mostly made up of the globemallow tree.

In short, the idea that Megatherium was a giant glyptodont killer or a scavenger as suggested in the paper is completely bogus. It is little more than a claim based on “The Rule of Cool” (http://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool). Scientific evidence has shown us that ground sloths were large herbivores, and although badass, were not likely to eat your remains after they beat you to a bloody pulp.