I recently made this team, and I think it is pretty powerful.
Teambuilding Process-
I wanted to make a team based on Mega Aerodactyl, one of my favorite Mega Evolutions in UU. I thought that with the right support, Mega Aerodactyl could flourish in OU.
So first, I thought of things that completely shut Aero down. Things like Ferro and Landorus came up in my mind. After that I thought of a mon that could take care of both of those mons fairly easily. Keldeo was then added to the team. (Fire Fang was put on Aero for extra Ferro coverage.)
A Pokemon that really shut down my team was Rotom-Wash. I thought of choices like Tangrowth and Amoongus as additions to the team, but Latias seemed like the best choice because it resisted both of Rotom's stab moves and it could defog rocks (Volcarona was added to the team later, so this is HUGE.)
Thus far I looked at my team and realized, "welp, TTAr beats me once again". So i was between Landorus and Hippo, but Hippo looked like the overall better option. I made sure that I had Stealth Rocks because this team wasn't the most strong team you see.
After I added Hippo, i added pokemon that would support Aerodactyl. I saw an Ice weakness with my Hippo and Aerodactyl, and Grass hit Keldeo and Hippo, so I saw Volcarona as a very viable option. I also wanted a sweeper on my team. With it being 4x weak to Rocks, I needed Defog, which was put on to Latias.
My last Pokemon was a toss up between Scizor and Rotom Wash, but I decided that Scizor was the best option for 2 main reasons: Knock Off and Priority. Knock Off was a must-have for things like Landorus and Chansey running around the meta, and I did not have priority at this point so Bullet Punch was a must have.
Threat List-
Talonflame: Only thing on this team that can switch in is Aero, but still doesn't want to get burned.
Tyranitar: Even with Hippo, Pursuit-trapping TTar remains a threat on my team because of Volcarona and Latias hopping around.
Rotom Wash: Volt-Turn kind of wrecks my team, and a Hydro Pump from a Rotom will do a number to pretty much anything.
Mega Lopunny: This thing has so much coverage that it can probably 2HKO everything on this team.
Sample Battle-
http://replay.pokemonshowdown.com/ou-445030532
Pastebin Link-
http://pastebin.com/bMjjiBxc