If you pick it up with an argy, hit it once or twice before dropping it. After it goes through it's heal animation, pick it up and hit it once more. Drop it, tranq it slowly so as to get more heals, and then once it is KOed, put whatever food you want to take with in it's inventory. I KOd one I hit a few times with my argy, and once I put iguanodon kibble in it's inventory it tamed in a matter of seconds, basically meaning one can starve tame daeodon without having to wait, force feed narcos, and then give it food. Happy taming!
Values above are incorrect, a 140 probably needs about 40kibble. They eat very quickly, are easy to knock out, tame like you would tame anything else with one factor to keep in mind, they are almost always in a pack of 3 so however you would tame a dire wolf, use that same strat.
Alene, they don't have too much of a use. As a pack, they will heal up annoying amounts of health. Keep them in pairs for base defense along with triplets of microraptors and small packs of raptors for a visciously effective and tanky crew that don't look too dangerous from afar. Add pegomastaxes to the mix to steal loot from your unfortunate attackers.
Knocking them out is rather easy, and their taming time is insanely quick because of their food consumption, but the hardest part is gathering enough prime meat for them to eat in one go. Not the easiest task.