Avocados are delicious. That’s an undisputed fact. But you better not take that glorious green gift from nature for granted: It turns out avocados should have gone extinct long ago.

Thanks to Reddit user Bpbegha, we learned that avocados actually evolved alongside giant ground sloths during The Cenozoic Era.

The giant sloths and their giant friends—including the Toxodon (who was sort of what you would get if you combined a rhinoceros and a hippo), the Glyptodon (a really big armadillo) and the gomphotheres (a crazy-looking elephant with a couple extra tusks)—devoured avocados whole. Being giant themselves, passing giant avocado pits wasn’t a problem and they happily deposited the seeds (along with some extra fertilizer) across the American continent.

Unfortunately for avocados, those guys disappeared from the earth roughly 13,000 years ago. These days, there are not many massive mammals able to poop out a pit that size—and avocados haven’t yet gotten the memo.

By about 5,000 BCE, humans had arrived on the scene and were cultivating avocados for consumption (back then they were called ahuacatl—the Aztec word for testicle—because, well, just look at them). But scientists still wonder at how avocados and other so-called “anachronistic fruits” managed to survive until then, without giant sloth friends to spread their seeds.

Horses, jaguars, and even squirrels have all been floated as potential purveyors of the pits but no one knows for sure.

Either way, we owe a lot to the giant pooping sloths of yesteryear for doing their part to spread avocados across the land—not to mention the brave struggle avocados undertook to survive all those years after they were gone.