You have a Ditto with perfect IV's? My best overall Ditto has 31/4/30/0/29/30 but I have loads, and a few more with 31's so I have all stats covered. I like breeding for the nature first, then try and breed in IV's to where I need em. But if possible I like to be able to just breed the same species together rather than stick to Dittos. Eggs are produced faster, and by selecting for offspring, if I wanted say... 31/31/31/x/x/31 for my Breloom (which is a Breloom I recently hatched, and my crowning glory). Then I'd want to try and breed two Brelooms who have at least all 4 IV's covered, preferrably 2 and 2 (i.e. one with 31HP/31Atk and another with 31Def/31Spe). And whenever I hatch one with more overlap, I'd rather throw that in as well, to increase the odds of inheritance.
An Aerodactyl though, especially as a suicide lead, is fairly easy to breed for. Get a Ditto with 31 Speed, or 31 Attack. And breed it with an Aerodactyl. Get an offspring with either 31, then breed that offspring with another ditto that has the other 31. Then it's just a waiting game.
Hope that helps :)