Fire fang, it covers Aerodactyl's ice and steel weakness but honestly I can't recommend either because his main rock STAB covers ice and Earthquake covers his Steel, Rock and Electric weakness. If you don't have acsess to them then diffidently go fire fang
Easy Peasy: Ice Fang
You know how common Dragons are in the meta and plus you get that coverage on Ground and Grass. Simple. Hope it helped.