Fossil
Fossils can be used to revive prehistoric Pokémon whose Eggs are not placed in the Lab. They are found by scouring. When a Pokémon returns with a fossil, it will be placed in the Fossils section of the Inventory.
Reviving Fossils
Once obtained, the owned fossils can be found and revived in the Lab. Reviving a fossil requires 1,500 Interactions (not the same as interaction points), then the revived Pokémon can be placed in the Party if there is an empty spot. Otherwise the user will be prompted to place a Pokémon into a field to make space for the revived Pokémon. Reviving a fossil while Shiny Hunting does not break the chain, as they are not hatched from an Egg. As of right now it is unknown if it is possible to get a shiny or albino from reviving fossils.
A revived Pokémon is designated by a Prehistoric icon next to its gender. If a prehistoric Pokémon is placed in the party, then it gives a bigger boost to the EXP gained by Eggs of the same species than a normally hatched Pokémon. ???