When you encounter a wild Carnotaurus in or near a forest, walk towards him, so that he is between you and the trees. He will go away from you to attack you with his charge run attack. By doing so he has a high chance of getting stuck between the trees. Now you can knock him out savely. But remember to chop down the trees when he is knocked out, because when he is tamed he will start running and bugging when the trees are still there.
Back when I was level 28(that was 11 months ago) I WAS STILL ON HETBIVORE ISLAND! Like seriously there's nothing to tame but dodos, persons and paras, until I found a black egg... I thought it belongs to that therezinasaurus who decided to show up but before I pick it up I read what it said and I was exited! A carno egg! I trackt down the carno and knockt him out using tranqs and crossbow(he is a bit slow) I ran home to grab narcotics and showed dodomeat down its throat and after 46m i hade a carno
You just need a couple trank arrows, at least about nine, maybe some hide armor, and then climb up onto a rock that he can’t get up onto, then shoot him or something to Agro him, and once he comes to the base of the rock and attempts to kill you, shoot him with the tranks. Then when he tries to run away, just jump down and chase him. But make sure he doesn’t get KOed in water.