When taken to Cinnabar Museum in Red, Blue, Yellow, FireRed & LeafGreen, or Oreburgh Museum in Diamond, Pearl & Platinum or Pewter Museum in HeartGold & SoulSilver, this fossil will be revived into the Pokémon Aerodactyl. This item was a Key Item in FireRed & LeafGreen but you can obtain many in later games.
Aerodactyl Level 20
Trainer Memo: ??? Nature. Date of Obtaining Obtained at Pewter Museum. Met at Level 20