Things You'll Need
Instructions
Fly to Violet City and head south onto Route 36. Continue heading south until you reach the Ruins of Alph.
Approach one of the many fractured rocks outside the Ruins of Alph. Press "Start" to open the in-game menu. Select Pokemon and choose the Pokemon that knows Rock Smash to break open the rock. You may run into wild Pokemon such as Geodude or find a variety of items such as colored shards, Max Revives and various fossils. If you do not find an Old Amber fossil, continue using Rock Smash to break the rocks until you acquire one.
Head to the Kanto region via the magnet train at Goldenrod City or by surfing east from New Bark Town and crossing through Tohjo Falls.
Fly to Pewter City. Enter the Pewter City museum to the north of the city and speak with the scientist. Give him the Old Amber fossil to revive.
Exit and re-enter the museum. Speak to the scientist again to receive an Aerodactyl.