Similar in function to Egg Vouchers, Fossils are rare items that can be used to obtain a special class of Novelty Pokémon eggs. Based on the same objects found in the canon games, the Fossil items when used automatically place the egg in the user's party. However, the egg "resurrected" from these items is not that of the canon Pokémon, but of a truly "fossilized" form of the Pokémon, often complete with cracks and gaps. These items can most commonly be obtained from the Underground, though can also be purchased from the Prize Shop for 15 Prize Points, where two Fossils are rotated every twelve hours. Unwanted Fossils can be sold for 5,000 Points.
The first eight Fossil items, corresponding to the items found in the Generation I through IV games (aside from Fossil Relicanth, whose fossil sprite is custom), were first released in February 2010 alongside the introduction of the Underground system. The Generation V items were released as rewards for the March 2011 Site-Wide Shiny Hunt, and the Generation VI items were released as rewards for the November 2014 Site-Wide Shiny Hunt. The description for the two Generation VI fossils erroneously refer to Tyrunt & Amaura as having "lived in the sea in ancient times", which seems to be accidentally duplicated from the description of the Cover Fossil.
The Achievement "Ruin Maniac" can be unlocked by having the first 14 Fossil Pokémon registered in the Pokédex.
For more information about the Novelty Pokémon given by the Fossil items, see Fossil Novelties.
List of Fossils
Three items known as Artifacts are a unique subset of Fossil items that were released following the May 2016 Site-Wide Shiny Hunt. Each can be used to summon a Novelty Pokémon egg, which are based on the three giant Pokémon from the Pokémon animé episode The Ancient Puzzle of Pokémopolis. Like the normal Fossil items, they can be found sometimes from the Underground. However, unlike them, they seem to have a lower drop rate, they cannot be purchased from the Prize Shop, and they have an increased selling price of 10,000 Points.
For more information about the Novelty Pokémon given by the Artifact items, see The Ancient Artifact Trio.