To complete Hoenn Dex I need Anorith, but don't know what fossil it comes from. Which one, and where can it be found?
Anorith comes from the Claw Fossil. You get it in the desert on Route 111, but you have to choose between it and the Root Fossil (Lileep). Picking one will cause the other to disappear, thus you need to trade for the other fossil Pokémon.
That would be the claw fossil in the desert. If you chose root fossil, you will need to trade for him.