If you like a easy challenge use a trike and have a trike saddle get on and go at him/aka/spineasouras once he starts running get him cornered then get off and kill him your self but he can still do damage
People need to talk about mobile more.I’m on mobile and what I find best is to tame two turtles and go after some arges.But you can build some spike walls( wood or metal) and lead some “NON AGGRESSIVE” massive claw butchering Dino to them and wait until dead to harvest. (If u do this make sure to have a bed to respond in)
How to get a shitload of prime: Use a flyer (preferably an argent) and pick up an ant. Then drop the ant next to a megatherium. It will go on a killing spree but never harvest the bodies. Once it has finished, go down an collect your prizes. This works best near the redwoods as the most creatures live there that will drop prime.