You can revive them by talking to the man in the museum in Oreburgh city
Revived from Armor Fossil (Pearl only)
The Dome Fossil can be revived into the pokemon kabuto.
The fossil Pokemon available in Pokemon Emerald include Anorith, revived from the Claw Fossil, and Lileep, revived from the Root Fossil.
The helix fossil, when revived, will become Omanyte.
When revived, the Dome Fossil will be Kabuto.
Tirtouga comes from the Cover Fossil.
If you choose the Helix Fossil it can be revived into an omanyte. The Dome Fossil can be revived into a kabuto. I suggest you pick based on what pokemon you like better.
The dome fossil, when revived, will become Kabuto.
In Pokemon LeafGreen, the Dome Fossil can be revived into Kabuto, and the Helix Fossil can be revived into Omanyte.
there is a backpacker in relic castle who will give you either a plume fossil (which is revived into an archen) or a cover fossil (which is revived into a tirtouga)
Take it to the museum in cinnabar city to have it revived
Fossils can be revived at the Museum in Pewter City.