Helix Fossil

The Helix Fossil is a fossil that Omanyte can be resurrected from. You can get the Helix Fossil in underground in Diamond, Pearl, and Platinum. The Helix fossil can also be obtained in Heart Gold and Soul Silver, through smashing breakable rocks in the Ruins of Alph and other places. It can also be obtained at Mt. Moon after defeating a Super Nerd in Pokémon FireRed and LeafGreen and Pokémon Yellow.

https://vignette.wikia.nocookie.net/pokemon/images/5/5d/Mine_Helix_Fossil_1.png/revision/latest?cb=20110524004607