A new feature introduced in Pokémon Omega Ruby & Alpha Sapphire is Prehistoric/Primal/Primeval Pokémon. These Pokémon seem to work in a similar manner to Mega Evolution through a process called Ancient Devolution, and sends the Pokémon back to their prehistoric state. Full details on this feature are not known
Prehistoric Groudon
US Name: ??
Jp. Name:
Prehistoric Groudon
Type: ??
Classification: Continent Pokémon
Height: ??
Weight: ??
Ability: ??
First Appearance: Pokémon Omega Ruby & Alpha Sapphire
Details:
This Pokémon was first revealed on the Pokémon Omega Ruby box-art.
Prehistoric Kyogre
US Name: ??
Jp. Name:
Prehistoric Kyogre
Type: ??
Classification: Sea Basin Pokémon
Height: ??
Weight: ??
Ability: ??
First Appearance: Pokémon Omega Ruby & Alpha Sapphire
Details:
This Pokémon was first revealed on the Pokémon Alpha Sapphire box-art.
/This information was taken form serebii and serebii is a more trust worthy source then you so I will continue to call them prehistoric pokemon