Most obvious Rock/Grass would be a stegosaurus.... But with Turtwig line being a thing... specifically Grotle, I think a Grass stegosaurus would seem a little too familiar.
I don't see anything at all similar between Grotle and a Stegosaurus....like literally nothing at all....
But I'd also be on board with a wholly mammoth or a Parasaurolophus.
That being said I also think that not every dinosaur has to be a fossil, considering Pokemon like Tropius are a thing.
I'd like to see flying/ ground, as Archeopteryx was considered the "missing link" between dinosaurs and birds.Original Archen/Archeops: dragon/flying
If we had a Grass stegosaurus it likely have leafy back "plates". Which might look like Grotles leafy back. And they would have similar body shape.
Although.... Maybe the plates could be made of wood......
I imagine a stegosaurus being Rock/Electric with it's plates being charged gem stones that glow from charged electricity.
Eh, Grotle's body plan doesn't resemble a Stegosaur all that much, and it basically has ridges made of hedges/shrubbery on it's back, while a stegosaurus' plates might be represented by single, large leaves or something like that. Or Fungus.
But yeah a Rock/Electric stegosaurus with gemstone plates would be badass as well. Or a Rock/Electric (Or Rock/Fire) dimetrodon, with a electrically or thermally charged crystal sail.
I can't really see them doing a fossil Pokemon based on prehistoric rhinos, bears and other modern animals because the Pokemon versions of those animals are already so much more fantastical. I would like to see some of those weirder mammals though. Or, a big terror bird.
I'd also love to see a Rock/Psychic Doro bird. I had an idea that it's facant expression and extinction has to do with it being so lost in thought and focused on learning the secrets of the universe that it didn't bother to put much but minimal brain power to it's survival.
i want to see a stegosaurus
but it would be nice for them to discover more things about fossils we didnt know about before. maybe they found a mummified version of something that they normally find fossils of instead.
like if somehow the rock types of these fossils actually was something else before but its rock because its a fossil, so it would be cool to discover say one of the older fossils real typing.
or something to expand on the fossils..
What about having them make a Skull Island type island. All of the fossil could live there in their natural state. They could even have an unaltered Genesect be the big boss of the island similar to King Kong. Either that do time travel and allow players to explore their natural habitat.
I've been thinking about a fern fossil Pokémon that could be introduced even though we already have a Grass/Rock fossil Pokémon already. It would be nice to see some variety in plant fossil Pokémon instead on focusing on the dinosaurs.