Thanks to Jimmywrobinson1 for the scenario!
You were out studying fossils near a newfound place. It was here someone very recently discovered part of a Fossil of a Pokémon they didn't know of. So you were here to try and recover the rest of the parts. While your digging you hit a weak spot and the ground falls pulling you into a under ground cave. When you wake up, you find yourself inside a deep dark cave. You start exploring around to find an exit until you stop. Hearing something else.
Choose yer Prehistoric Pokémon!
Switch is okey