What are all the fossils you can get in Pokemon Diamond?

You can't actually get fossils in Pokemon Diamond! You can get fossils in Pokemon Pearl and Platinum, but not in Diamond.

Here are the fossils you can get in those games:

Pokemon Pearl and Platinum

* Fossil: Helix Fossil - Evolves into Cranidos

* Fossil: Dome Fossil - Evolves into Shieldon

* Fossil: Claw Fossil - Evolves into Anorith

* Fossil: Armor Fossil - Evolves into Armaldo

In those games, you can find the fossils in the Grand Underground. Then you can take them to the Fossil Restoration Man in Oreburgh City to revive them.