Fossil Pokémon are Prehistoric Pokémon which can be obtained from their specific fossils.
All of these Pokémon are Rock-Type with the exception of the four Galar fossil Pokémon. They all evolve at Level 40 with the exception of Cranidos and Shieldon, which evolve at Level 30, then Archen and Tirtouga, which evolve at Level 37, and Aerodactyl, who Mega Evolves using its Mega Stone. Any Fossil can be also found in the Underground in 4th Generation games.
Generation I Fossil Pokémon
These Pokémon can be obtained in Pokémon Red and Blue, Pokémon Yellow, in Pokémon FireRed and LeafGreen and Pokémon Let's Go, Pikachu and Eevee! by handing their fossil over to the weird scientist at the Lab on Cinnabar Island.
Kabuto and Kabutops
Omanyte and Omastar
Omanyte is the spiral Pokémon. It is a Rock/Water-Type Pokémon revived from a Helix Fossil. It evolves into Omastar. Omanyte's name and design come from Ammonites, prehistoric mollusks that lived from the Mid-Paleozoic Era to the end of the Cretaceous Period.
Aerodactyl is the fossil Pokémon. It is a Rock/ -Type Pokémon revived from Old Amber. Aerodactyl is the only Fossil Pokémon that doesn't evolve. Its name and design are based off of the ancient flying reptiles known as Pterosaurs (Pterodactyls if you so desire), and it bears a striking similarity to the Dimorphodon. Aerodactyl had a unique type combination until Generation V. In the game and manga it was revived on Cinnabar Island.
In Generation VI it gets a Mega Evolution.
Generation III Fossil Pokémon
These Fossils can be found in the desert area east of Lavaridge Town in Pokémon Ruby and Sapphire. They are in the Crumbling Tower which requires a Mach Bike to get to the top. They can be brought back to life by a Devon worker in Rustboro City. You can get the fossil you did not choose after beating the Elite 4 and going to the fossil maniac's house.
Anorith and Armaldo
Lileep and Cradily
Lileep is the sea lily Pokémon. It is a Rock/Grass-type Pokémon revived from the Root Fossil. It evolves into Cradily. It is based off of Crinoids (or sea lilies), an ancient, plant like group of animals.
Relicanth is not a true Fossil as it can be found in the wild and does not need to be revived, however, it is an ancient living fossil. It is a Water/Rock. It is also inspired by the real- world "living fossil", Coelocanth.
Generation IV Fossil Pokémon
You can bring these Pokémon back to life at the Oreburgh Museum.
Cranidos and Rampardos
Cranidos is the head-butt Pokémon. It is a Rock-Type Pokémon revived from a Skull Fossil. It evolves into Rampardos. Its fossil can only be obtained in Pokémon Diamond or in Pokémon Platinum if the last digit of your trainer ID is an odd number. It is based on the dinosaur Pachycephalosaurus.
Shieldon and Bastiodon
Shieldon is the shield Pokémon. It is a Rock/Steel-Type Pokémon revived from an Armor Fossil. It evolves into Bastiodon. Its fossil can only be obtained in Pokémon Pearl, and Pokémon Platinum if the last digit of your trainer ID is an even number. It is based on ceratopsian dinosaurs, like Triceratops, but it bears the most resemblance to that of a Pachyrhinosaurus.
Generation V Fossil Pokémon
These fossil are found inside the Relic Castle the player can bring these Pokémon back to life at the Nacrene Museum.
Tirtouga and Carracosta
Tirtouga is based on an Archelon and is the prototurtle Pokémon. It is a Water/Rock-type Pokémon revived from a Cover Fossil. Carracosta is the evolved form of Tirtouga. It is a Water/Rock-type Pokémon.
Archen and Archeops
Generation VI Fossil Pokémon
Tyrunt and Tyrantrum
Tyrunt is based on a Tyrannosaurus Rex and is the royal heir Pokémon. It is a Rock/Dragon-type Pokémon that is revived from the Jaw Fossil. Tyrantrum is the evolved form of Tyrunt. It is a Rock/Dragon-type Pokémon.
Amaura and Aurorus
Generation VIII Fossil Pokémon
Dracozolt, Arctozolt, Dracovish, & Arctovish
All four are based on the 'Fusion Fossils' made during the Bone Wars. Scientists often put mixed up dinosaurs fossils together, hoping they would look normal. This lead to some inconsistencies in fossils, like putting their heads on tails or making up completely new dinosaurs. The pieces consist of Pokémon resembling a Dacentrurus, a Velociraptor, a Dunkleosteus, and a Mosasaurus, respectively. They are the first Fossil Pokémon to not have the Rock-type.
- Dracozolt is a Electric/Dragon-type Pokémon and is revived from a Fossilized Bird and a Fossilized Drake.
- Arctozolt is a Electric/Ice-type Pokémon and is revived from a Fossilized Bird and a Fossilized Dino.
- Dracovish is a Water/Dragon-type Pokémon and is revived from a Fossilized Fish and a Fossilized Drake.
- Arctovish is a Water/Ice-type Pokémon and is revived from a Fossilized Fish and a Fossilized Dino.
- While normally just a Legendary Pokémon, a Groudon fossil is recovered by Butler in Jirachi: Wish Maker and used to resurrect it as Virus Groudon.
- Genesect were restored from fossils by Team Plasma.
- Generation II and Generation VII are the only Generations not to introduce its own Fossil Pokémon.
- This makes it so that Generation VII is the only odd-numbered generation that didn't introduce any Fossil Pokémon.
- Generation I is the only Generation to introduce three fossils from which to get fossil Pokémon.
- The fossil Pokémon in Generation I are the only Rock-type Pokémon that aren't part Ground-type introduced in that Generation.
- Most of the Fossil Pokémon have special attributes:
- Aerodactyl is the only Fossil Pokémon that doesn't evolve (not counting Mega Evolution). It is also the only Fossil Pokémon that used to have a unique type but now does not.
- Cranidos and Rampardos are the only Fossil Pokémon that aren't dual type.
- Archen and Archeops are the only Fossil Pokémon that don't have a Hidden Ability.
- Tirtouga and Carracosta are the only Fossil Pokémon that have the Rock-type as their secondary type.
- All of the Fossil Pokémon in Generation VIII are the first to not have the Rock-type or have genders.
- The Cranidos line are the only single-type Fossil Pokémon.
- The Tirtouga line are the only Fossil Pokémon to have the Rock-type as a secondary type instead of a primary one.
- The Generation V fossils and the Generation I fossils share their type combinations.
- The Lileep line is the only Fossil Pokémon that is based on an animal that still lives in the modern age.