The easiest way to tame a Dunkleosteus:-

1) Tame a Baryonyx.

2) Bring a scuba gear.

3) Bring a really good crossbow to knock it out.

4) Find a Dunkleosteus (mainly found in deep ocean).

5) Kill all hostiles around it.

6) Use Baryonyx's spin attack to stun a Dunkleosteus.

7) Then knock it out with crossbow (hit on it's body because it's head is fully armored).

8) Then feed it superior kibble, raw mutton, raw prime meat etc.

9) You have a Dunkleosteus.

10) It's really good for harvesting oil from oil nodes in the ocean.

More Dunkleosteus Taming & KO Tips