Fossilized Dino

Fossilized Dino is a fossil in Sword and Shield that can be used to resurrect Arctovish when combined with the Fossilized Dino, respectively.

https://vignette.wikia.nocookie.net/pokemon/images/3/3c/Fossilized_Dino.png/revision/latest?cb=20191122050030

Trivia

 * It is a plesiosaur according to its Japanese name.