Pokémon has been neglecting fossil Pokémon for the past three generations, so it's very likely new additions will be added in Generation 10. Fossil Pokémon are some of the most creative designs in the franchise, and while they have little viability competitively, they still make for fun parts of a player's team. Some of this weakness is partly due to the requirement, outside of Generation 8, where one of a fossil Pokémon's types is always Rock. This is an issue as while Rock-Types have a good offense, they also have equally poor defense.
With the exception of Generation 2, every Generation from one to six received at least two new fossil Pokémon. For some reason, this trend stopped with Generation 7, and while Sword and Shield did have fossil Pokémon, it was with a new gimmick that combined different parts of prehistoric Pokémon. However, this did create some unique Pokémon, like Dracovish, who became a competitive monster. The recently released Generation 9 returned to an absence of fossil Pokémon, likely due to the prehistoric and future themes of the titles.
The Best Ideas For Fossil Pokémon After Gen 9
The best inspirations for fossil Pokémon after Gen 9 would be the Iguanodon and Troodon. Most fossil Pokémon are from relatively well-known species, making these two more notable dinosaurs prime options. The Iguanodon, while somewhat dated, has seen action in movies and television and is also one of the few known dinosaurs to have something akin to thumbs. The Troodon, while not as media famous, is still a popular dinosaur and believed to be the smartest one that ever existed.
How Each Of These Fossil Pokémon Would Work
The Iguanodon would be the franchise's first Rock/Fighting fossil Pokémon. It earns itself Pokémon's popular Fighting-Type due to its thumb-like claw and the fact that it largely used its arms to fight. In gaining the Rock Type, this Pokémon would lose its weakness to Flying Types, and while it would still hold all of Rock's weaknesses, having Fighting moves will help deal with them. Design-wise, the first stage could be a baby Iguanodon that is pure Rock, not gaining its ability to fight until it evolves into its larger form.
The Troodon would be a bit trickier but would make an excellent option for a Rock/Psychic type. The Troodon is believed to have been the most intelligent dinosaur that existed, even having the chance to become as intelligent as humans if they lived long enough. Though this alone does not give it extreme mental ability, the fantastical leniency Pokémon uses can allow for the jump. The Troodon would have a first-stage evolution, along with Pokémon's brilliant Psychic-Type weakness, as a hatchling with low stats and then evolve into its regular but still small form. This Pokémon would have a high Special Attack and be incredibly fast, but the drawback would be its fragility.
Fossil Pokémon will rarely be these competitive heavy hitters that dominate an entire generation, but they don't need to be. Instead, the goal of fossil Pokémon is to be this cool look into the past of Pokémon, further back than even the recent Scarlet and Violet went. Hopefully, Pokémon's Gen 10 will see the return of fossils in the way players are used to, and with any luck, these two could be possible additions to the historic franchise.
Source: Lockstin & Gnoggin/YouTube