Pokémon GO has all 151 Pokémon from the original games, including the famous fossil collection. Omanyte, Kabuto and Aerodactyl could be hatched using the fossils in Generation 1, and all three of those, along with the evolved Omastar and Kabutops, are available and out in the wild in Pokémon GO. Here’s how you can find them!
Omanyte is fairly rare in Pokémon GO but not TOO rare, and because it is a water type, it’s going to be most commonly found near water. It’s also a rock type, though, so deserts and farmland come into play.. As far as eggs go, they’re most commonly found inside of the 10km eggs.
Omastar on the other hand is EXTREMELY rare. Like Omanyte, the most common location to find an Omastar is near a water source, although like all rares, they tend to show up near areas crowded with Pokéstops when multiple stops have lure modules dropped on them. Otherwise, find or hatch Omanytes and then evolve one of them into an Omastar as soon as you can.
Kabuto has been reported commonly near beaches, river, lakes and other water locations, but being partially rock type it will spawn near farms and deserts. In addition, you’re more likely to find a Kabuto at night as opposed to during the day. Like the Omanyte, Kabuto also most commonly hatches out of the 10km eggs, so make room in your egg stash to acquire more of them for a better chance at earning Kabuto.
Kabutops, like Omastar, is stupidly rare. If you have a water source with Pokéstops where you can drop a lure module at night, that’s your best bet, along with using Incense near a water source. Alternatively, just catch and hatch a bunch of Kabuto until you find a Kabutops. Some have been reported appearing away from water sources.
Aerodactyl, unlike all of the above, tends to appear in land-bound areas, especially desert locations, farmland, or especially farms in the desert. Being half flying type, it’s also expected to spawn in parks and forests. 10km eggs are a common method of finding Aerodactyls, as well, especially if your location isn’t conducive to finding many of them.