Neither the Helix Fossil nor the Dome Fossil will become an aerodactyl. In order to obtain an aerodactyl you must revive a pokemon from the Old Amber item which can be obtained in the Pewter City Museum.
Helix Fossil is a Omanyte. Dome Fossil is a Kabuto. The Other one is a Aerodactyl. The Aerodactyl fossil is in the Pewter City Museum.
Neither, Aerodactyl is revived from Old Amber. You get Old Amber from a scientist in the Pewter Museum (cut down the tree on the right to get to the other entrance). The Helix fossil revives into an Omanyte, while the Dome fossil turns into a Kabuto. Both are Water/Rock-types.
Helix fossil turns into Omanyte once you bring it to the Fossil guy on Cinnabar Island in the old Research facility. The Dome fossil turns into Kabuto. And then you can get the Amber from the Museum, which will turn into Aerodactyl
Helix Fossil - Omanyte Dome Fossil - Kabuto Old Amber - Aerodactyl Root Fossil - Lileep Claw Fossil - Anorith Skull Fossil - Cranidos Armor Fossil - Shieldon -------------------------------------------
skull fossil : cranidos root fossil : lileep old amber : aerodactyl helix fossil : omanyte dome fossil : kabuto claw fossil : anorith armor fossil : shieldon
Dome Fossil = Kabuto (Lv 40, evolves to Kabutops) Helix Fossil = Omanyte (Lv 40, evolves to Omastar) Old Amber = Aerodactyl
no but you can get a dome fossil or helix fossil the dome fossil is kabuto and the helix is omyante
helix.
From the Skull Fossil, you get Cranidos. From the Armour Fossil, you get Shieldon. From the Claw Fossil, you get Anorith. From the Root Fossil, you get Lileep. From the Helix Fossil, you get Omanyte. From the Dome Fossil, you get Kabuto. From the Old Amber, you get Aerodactyl. Courtesy of Josh, England.
Kabuto is the Dome Fossil, and Omanyte is the Helix Fossil. An easy way to remember is that a helix is a spiral, and hermit crabs, such as Omanyte, have a spiral shell.
Dome fossil is Kabuto and Old Amber is Aerodactyl.
helix, dome is better in fire red