The Plume Fossil (Japanese: はねのカセキFeather Fossil) is a Fossil introduced in Generation V that can be regenerated into Archen. It is the counterpart of the Cover Fossil.
A fossil from a prehistoric Pokémon said to be an ancestor to modern bird Pokémon. It looks as if it could have come from part of some creature's wing.
The Plume Fossil was introduced as an Item card in the Pokémon Trading Card Game in the Noble Victories expansion, first released in the Japanese Red Collection. It allows players to look at the bottom seven cards of their deck, reveal an Archen they find there, and put it onto their Bench. The other six cards are then shuffled back into the deck.
The Scarlet & Violet Series saw the release of Antique Plume Fossil in the Japanese White Flare expansion. This card is unlike the previous Plume Fossil card and more in line with other Item cards depicting Fossils, allowing the player to play it onto the Bench as if it were a Colorless-type Basic Pokémon. It has an Ability that prevents all damage done to it by attacks used by the opponent's Pokémon if it is on the Bench.
Unidentified Fossil cards are Fossil Trainer cards which become Basic Pokémon. While they do not feature a Cover Fossil, they can still be used to evolve into certain Tirtouga.
Trivia
While the item description for the Plume Fossil states the Fossil came from a "Pokémon that (once) flew/lived in the sky", the Backpacker who gives away the Fossils in Pokémon Black and White mentions that the Plume Fossil is from a Pokémon that lived in an ancient forest, but could not fly. Considering what is known about the Archaeopteryx genus, this may be intentional to some degree.
