I need some help with a Mega Aerodactyl set. So far i came up with these 2 attacks: Double-edge and Earthquake. What other moves are good on it? (I will be breeding a Rock Head ability one on my emerald for Double-edge)
Also i was thinking of using a Adamant nature for the extra damage. (Cause dont his Mega grant more speed?)

Mega Aerodactyl has base-150 speed, which should be enough to outspeed more or less anything that isn't Scarf'd even without full investment in it.

Other than that, I don't really know, Aerodactyl isn't a Mega I use (or see) very often.

Well i never really used it before in its Mega form, but i do sometimes see it and kinda give me hard time if my team cant counter one.

Since it loses Rock Head for Tough Claws. Just give it the Usual
Stone Edge
Aqua Tail
Crunch (If it gets it)
And any Stab Flying move
or Earthquake

I guess those moves work, i'll still breed for double-edge if i dont use its Mega form. (I could use lifeorb on a non-mega Aerodactyl though)

Iron Head isn't a bad move either since it takes out Fairy and Ice types and has increased damage from it's ability.

Does his Mega grant any new typing too? (Like most megas do) I forgot to look it up.

No It Stays Rock/Flying.

(I haven't made a competitive set in months so I don't know how good these are)

3 possible movesets:

Mega Aero:

Iron Head/EQ
Crunch/Return
Aqua Tail
Stone Edge

Iron Head and EQ can be swapped depending on what you want coverage for (Iron Head covers Ice and has 104 power with Tough Claws, EQ covers Electric and retains 100 power because it doesn't directly contact the opponent). Crunch and Return can be swapped depending on the strategy you want (Crunch covers Psychic and Ghost but offers 104 power, Return covers nothing but offers 133 power at max). Aqua Tail covers Ground and Rock with 117 power, and Stone Edge covers Flying with 150 power, making them both musts.

Regular Aerodactyl (Fake-out Mega)

Your opponent probably expects a Mega. This is not one.

Double-edge
Stone Edge
Aqua Tail/Iron Head/Crunch/Roost (pick two)

Rock Head makes Double-edge a great move, end of discussion. Stone Edge still has 150 power and is still a great Aerodactyl move. The last two moves depend on strategy. Aqua Tail, Iron Head, and Crunch are there for damage and coverage. Roost brings an interesting strategy into the mix. For one, it heals 50% of your HP. It also takes away the Flying sub-type for one turn, which could be used to render an Ice/Rock/Electric move less effective if you want to check what an opposing Pokémon might use against Aerodactyl.

Sandstorm Aerodactyl

This would be used as part of a team, probably. If you're not using a Sandstorm team for the Aerodactyl, this might not be a good set.

Sandstorm
Double-edge
Stone Edge
Crunch/Aqua Tail/Iron Head/Roost

Most of the set is the same, because of Aerodactyl's limited physical movepool and abysmal Special Attack. However, Sandstorm is added to make Aerodactyl more bulky. In a Sandstorm, the defenses of Rock-types get multiplied by 1.5x. If a small amount of EVs are deposited into Aerodactyl's defenses, this strategy can actually make him surprisingly bulky.

Those 3 sets look great. I'll try the first one (Breed it in 4th or 5th gen) The 2nd one i'll have to try to get good ivs to breed for use of Double-edge with the non-mega set.
But getting a good 3rd gen Ditto to breed with will take some time getting, even if i use emeralds broken rng.

I have actually had a fair amount of success using mega aerodactyl. I prefer an adamant nature with max speed and attack because he outspeeds everything base 130 and under even with a neutral nature and he.really needs the extra power. I think this.moveset is the best for him:

stone edge
earthquake
crunch
stealth rock/fly

You might think I am crazy for suggesting fly. However, due to tough claws, fly becomes aeros strongest move. It is more powerful and accurate than stone edge and flying is a very abusable offensive type (looking at you talonflame). Yes, fly is a two-turn move, but mega aero has the speed to abuse it. Mega Aero comes in and forces a switch as it flies up, the next pokemon comes in to take a tough claws boosted fly and then will most likely be outsped and be threatened by the perfect coverage that edge/quake provides. Overall, mega aero is an excellent revenge killer and late game cleaner. Stealth Rock is only suggested to give mega aero more utility and allowing it to set up hazards forcing switches. Hope you like my set!

Lol So many options o.0