u simply take it to a sientist in mr.stones building
Chat with our AI personalities
there are different Pokemon in it
it is in the top right of the desert. you can choose between it and the claw fossil
As soon as you give it leave the whole building go back inside talk to the guy who took the fossil to receive your very own Lileep(root fossil) or Anorith(claw fossil).
To get a Lileep in Pokemon Ruby, Sapphire and Emerald you need to revive a Root Fossil. The Root Fossil can be found on Route 111 however choosing it will cost you the ability to get the Claw Fossil. Alternatively you can trade for a Lileep from another game if you've picked the Claw Fossil.
1. You go to the desert and pick the root fossil 2. Take it to a guy on a computer at the Devon corporation in Restrubo 3. Go out of the room, go back inside, and receive your lileep