Diplo's are super tanky. Everyone doesnt realize this is now the BEST bullet tank in the game. When heath is low, sprint out with no problem. Unlike the bronto, the Diplo is very fast. While passive taming, realize that first feeding you have about 15 minutes until next feeding. Then all quick after that.
You can take it by having a good amount of mejoberries then allign yourself under it to where it stands still and can't knock you back. You can easy kill it too to get a saurpod vertebra I got one that way