The best way to tame it is have on person driving a raft and the other person shooting at the carnos. After they die, go to land and set a large bear trap. This will cause it to get stuck and you can easily knock it out. Hope this helps.
It really is that simple though, they can't reach you or your flier on a big enough rock, so if you don't want to make a trap you can just shoot down from a rock or cliff once the carnos are dealt with. Be ready for a goose chase once it starts running.