This tame is best to do with multiple people, or about 3-4 water Dinos. Every time you feed it,you'll aggro all mantas and sharks in the area.raw prime spoils super fast so tribe mates will need to make extra runs for it.
This creature is so easy to tame. All you need is:
1. An Ichthyosaurus(these guy won't be attack by any water creature, except the jellyfish)
2. Anykind of meat(I suggest using prime meat and don't use fish meat)
3. Find one of these creature
4. Feed it prime meat(It's a long time between the 1st and the 2nd feed, after the 2nd feed it's fast)
And then you get one of these, just be careful of the megalodons, they will attack right after it is tamed. I hope this is useful for you<3