By defeating Super Nerd Miguel at the end of Mt. Moon, you will be able to choose from two Fossils: the Helix Fossil, and the Dome Fossil. Later in the game, when you make it to Cinnabar Island where the seventh gym is located, you will be able to change your fossil back into a Pokémon at the laboratory. If you picked the Helix Fossil, your Pokémon will be Omanyte, and if you picked the Dome fossil, your Pokémon will be Kabuto.
The Dome Fossil can be revived into the pokemon kabuto.
Fossils cannot be created in Pokemon FireRed, there is a finite number of them to find.
The Left One
At cinnabar island at the pokemon lab third door.
Go to Mt. Moon and go until you fight this scientist person and then you will be able to get the dome fossil.
The Dome Fossil can be revived into the pokemon kabuto.
Helix
You Cant
Fossils cannot be created in Pokemon FireRed, there is a finite number of them to find.
The Left One
If taken to cinnbar island's research lab you can revive the Pokemon inside the fossil which will be Kabuto.
At cinnabar island at the pokemon lab third door.
Take it to the museum in cinnabar city to have it revived
cinnabar island research center
The ocean one in the museum.
give the fossil to the museim dude in peweter.(sorry about the bad spelling :)
Yeah you can. You can ask a friend who has one of the Kanto Games to trade a Pokemon holding the fossil and you can regenerate it, breed another Pokemon of the fossil it regenerates, then trade back!