Easiest and safest way to tame this is to lure it under water. They stop aggro and you can tame as you please. Just make sure you come up for air every once in a while. Also be sure the water is deep enough.
Dodo is wrong about amount of tranq arrows needed (crossbow). Lvl.19 arthro, it states 1 headshot or 3 hits. It took me about 15 and it died, thankfully. Boy did I freak out after the fifth arrow... I was running naked in the woods