It’s true! Archen adapted, slowly but surely, into other bird pokémon, depending on the habitat. This frequently resulted in branches of adaptations that became all modern-day bird pokémon.

Aerodactyl, on the other hand, actually belonged to a completely separate line of pokémon that ended with aerodactyl sometime in the late Cretaceous (likely as a result of the Cretaceous-Paleogene extinction event). While the descendants of archen included smaller, bird-like pokémon that could adapt easily to the resulting climate changes, the pterosaur-like pokémon such as aerodactyl were far larger and consumed more energy simply to move, and, well, that would be why they never survived past the extinction event, sad to say.

As for my favorite fossil, now that is a difficult question! I’m quite partial to kabuto myself, as they aren’t technically extinct but have managed to survive in smaller numbers and in extreme environments. Because of this, they’re our best window to the ancient world and could provide a whole host of answers to questions humans have been asking ourselves for aeons.

However, all of them are quite fascinating, and the shieldon family is likewise an excellent choice!