I found cranidos and bastiodon on the first one I had during mount Coronet. Then I got shieldon during my second distortion. Not sure if I got really lucky, or they're not that rare
The ice caves don't show on the map. Just fly around on braviary, and you should be able to find some holes on the ground. In those holes are ice caves. You can find zorua in at least one of them. I don't remember where I got mine exactly