You appear to have the Arctic and Antarctic confused. They're opposite ends of the world. There aren't any bears or lemmings in Antarctica at all. And there are penguins in the region, but they're amphibious rather than really being stuck on Antarctica.
Well, you're ⅓ there, considering that there are no terrestrial mammals in Antarctica. But I was talking about weed species, not those particularly evolved for a given niche.
