Perhaps you need to research and unlock them first? I don't play campaign (more of a sandboxer), so I'm not completely sure of this but I think you need to research alternate skins first before you can use them.

In sandbox you get all alternate skins.

Okay so I went to my Prefab Sandbox map, documented all the animal's skins. Went over to my Easy Mode Zoo, everyone has the same skins. So I think the achievement might be broken? It can't be that you have to place them, because I've done that with several dinosaurs. If it means I need to *place* one of each skin in the zoo......this'll take a while.

Ah, you mean that one achievement. Yup, you need to put each alternate skin type in one park/zoo to unlock it. Good luck.

Originally posted by Nederbeest:

Ah, you mean that one achievement. Yup, you need to put each alternate skin type in one park/zoo to unlock it. Good luck.

I did do this with Leaellynasaura and it didn't count, but I will try again with this update.

I am in the same boat. I even unlocked all skins AND have melanistic, leucistic and albinos for some of them, but the achievement just doesn't trigger. I am in challenge mode too and all of them are in my park ._. is the achievement still broken?