Happy Darwin Day! February 12th celebrates the birth of Charles Darwin (and, coincidentally, of Abraham Lincoln) in 1809. Chuck D would be 199 today (so next year's gonna be huge!) and in honor, we give the rundown on some of the creatures he studied.

Darwin's best finds came in South America, on his famous voyage on the HMS Beagle. Here he found fossil evidence of the following mighty beasts.

Megatherium: The size of an African bull elephant, with enormous claws on its feet, twenty feet tall when standing: Megatherium would be a terrifying foe... except that it was a sloth. (If only he were twenty-one feet tall, he could taste that text above him.) The giant ground sloth mostly ate plants, but there's some evidence that it would occasionally chow down on...

Glyptodon: The evidence that Megatherium ate this big fella is as follows: Glyptodon was the size of a VW Beetle, so only Megatherium was big enough to flip it over. Glyptodon, a relative of the armadillo, was a huge, armored mammal that ate the heavy plants growing along riverbanks.

Just try and flip me! I dare you!

Toxodon: This mighty ungulate (hoofed mammal) looked like a hippo, and he lived like one, too. Yet another herbivore, he probably chilled in the water until attacked by a Smilodon, or saber-toothed tiger to you and me.

Dum dee dum, just mindin' my own business...

In Australia, Darwin found less huge and less fossilized creatures. He especially enjoyed the next two, which prompted him to wonder if a separate Creator had made these strange beasts...

Rat-Kangaroo: A rabbit-sized jumping marsupial with a curly tail, the rat-kangaroo looks like, well, a little kangaroo. And that's pretty much what it is.

Platypus: The platypus is a true modern marvel. Along with the echnida, the platypus is the only modern mammal that lays eggs. It's also one of the few venomous mammals: the male platypus has ankle spurs that secrete a unique venom strong enough to kill a small animal or incapacitate a human. Throw a duck bill into the bargain and you get a creature that European naturalists, not unreasonably, thought was a fraud when they first heard of it.

So on this February 12th, celebrate the life and work of one of the great heroes of science. And you should probably start planning for next year-- it's the big bicentennial, and you know how the human animal loves to party.