>>22460516I think the idea is kinda Jurassic Park style: the Pokemon is cloned from genetic material in the fossil. Aerodactyl being revived from Old Amber is a pretty direct homage, even though there would be no DNA to speak of in properly fossilized remains. The Pokemon world is a fantastical place.
>>22460502Normal Aero abusing them with Rock Head would be fun, though he's already UU by nature of how great his Mega is. MAero is a surprisingly powerful Pokemon: a solid cleaner in OU that checks many prominent threats and an absolute monster in UU. He's always been one of those fringe Pokemon who is just powerful or useful enough to carve out some kind of niche and make it work. Never super popular, never hogging the spotlight, but always good enough to be relevant. I like him for that.
All of my favorite Megas wish they had more options, though. A few tweaks to movesets would make Pidgeot great and Aerodactyl amazing. Altaria turned out ok.