That reminds me, how long does it take a Tyrantrum to grow up and stop throwing tyrannosaurus tantrums? Ooh, and can you find Pokemon fossils while crossing the animals? Aerodactyl could soar over Arfferia.
The question one must then ask is: Were there ever Pokemon to have formed the fossils? Animal Crossing may occur long before prehistoric times with alternate technology levels, much like Earth in DragonBall.
i don't think it can have occurred before prehistoric times (in the sense of dinosaurs and some humans anyways) as there are hominin and dino fossils for certain
Do they ever explain why you are the only human in a land of demi-humans living above the remains of other humans? (I think you had a theory about this involving murder)