How to Get Armaldo in Pokemon Pearl

Encounter every native wild Pokemon species at least once to complete the National Pokedex. You cannot complete it until you have finished the game's storyline. You do not have to capture or defeat a Pokemon for it to count toward completing the Pokedex; you just have to cross paths with it. Check your Pokedex from the game's menu to see which species you have left to encounter.

Travel to the underground area in any portion of the map to search for fossils. You can mine certain walls in the underground area for fossils. Press the "Action" button near these walls to bring up the fossil mini-game.

Tap the screen with your stylus to dig for fossils in the underground. You need a Claw Fossil to obtain Armaldo. The Claw Fossil has a spiral shape to it. This is a rare fossil that you can obtain only after you've completed the National Pokedex.

Fly to Oreburg City and walk to the museum to extract an Anorith from the Claw Fossil. You can obtain multiple Claw Fossils and extract an Anorith from each one.

Train Anorith by using it in Pokemon Battles to increase its experience. Once Anorith reaches Level 40, you will be given the option to evolve Anorith into Armaldo.