I need an aerodactyl for my in game team
(Note: this is post game)In twist mountain, there should be a miner that gives you fossils every day.
If you are looking for an Aerodactyl for your team, you should go on Dream World.
Twist Mountain: From a Worker near the Ice Rock; randomly selected from all pre-Gen V Fossils Join Avenue: Randomly from Antique Shops' Polished Rock, Rough Rock, Rugged Rock, and Jagged Rock packages
Both methods are repeatable and only unlock after obtaining the National Pokedex.
Old Amber (Bulbapedia)
