Not long ago, ended up exchanging a few comments with a YouTube Creationist who laughably brought up Piltdown Man. Seriously, Creationists, when was the last time you ever heard us claim Piltdown was real? Really. You'd think that our unending laughter when you bring it up would clue you in on our opinion. Nowadays, if you want to prove evolution false, you'd have better luck by proving Piltdown Man was real.
Shanedk summarizes the whole Piltdown thing well:
This is just one example about Creationists doing things exactly backwards. It often makes me wonder if they're just so desperate, they're knowingly perpetuating the Big Lie.
Another example: The Crocoduck. This is another example Creationists should be desperately trying to find, but try to reverse it so that evolution has to find this critter that, if evolution is accurate, is impossible. Crocodiles and birds are on very different branches on the evolutionary tree. Large organisms never ever make a leap that big. In short, finding a chimera with the head of a crocodilian and the body of an avian (having characteristics that are part of the definition of the branches) would outright falsify evolution. It'd be like a dog giving birth to a cat (another example of Creationist Opposite Day) in outright violation of heredity.
Finding a real Piltdown Man, Crocoduck, or one species bringing forth a grossly different species is precisely what Creationists should be scrambling to do. Most know these things are absurd. But Creationism can happily explain them as "Well, God was in a weird mood that day," while evolutionary biology would be unable to explain any of those things. Of course, Creationism is an absurdity that can explain anything, including impossibilities and absurdities that don't happen. Evolution explains quite reasonably why zoology doesn't look like a D&D Monster Manual. Creationism can't explain why life looks the way it does, except to invoke random, unpredictable whims of a magic man.