Claw fossil

Claw Fossil is a fossil introduced in Generation III. When it is taken to a Fossil Reviver, it will be turned into the Old Shrimp Pokémon, Anorith.

Locations

 * Ruby & Sapphire: Route 111 (choice between this and the Root Fossil)
 * Emerald: Mirage Tower (choice between this and the Root Fossil) or Desert Underpass (if not obtained at Mirage Tower)
 * Diamond, Pearl, and Platinum: After you get the National Pokédex, go into the Underground and you will have a chance of finding a Claw Fossil.
 * HeartGold & SoulSilver: After you get the National Dex in Pokémon HeartGold, you can use Rock Smash in Cliff Cave to smash rocks and potentially find one.
 * Black & White: A Worker in Twist Mountain will give you one of the Fossils randomly after you get the National Pokédex.
 * Black 2 and White 2: A Worker in Twist Mountain will giveyou one of the Fossils once per day after you get the National Pokédex, or you can get one from a Join Avenue Antique Shop.
 * X & Y: After entering the Hall of Fame in Pokémon X, you can use Rock Smash in Glittering Cave to smash rocks and potentially find one.
 * Omega Ruby & Alpha Sapphire:  Route 111 (choice between this and the Root Fossil)
 * Sun & Moon: Trade a Pokémon holding it into your copy of Pokemon Sun or Pokemon Moon, as the Claw Fossil cannot be obtained through any other means.
 * Ultra Sun & Ultra Moon: You can buy a Claw Fossil from Olivia's jewelry shop in Konikoni City for 7,000 Pokémon Dollars in Pokémon Ultra Sun, or look for one in Poké Pelago on Isle Aphun: Path for Rare-Treasure Hunting! or Path for Interesting-Item Hunting!.