They're so annoying to deal with. Those things will rip through your flesh so quickly and never seem to have the will to be tamed as I found that out of the 50 I tried knocking out(Primitive Longneck) for an "experiment", 34 died.
They are also aggressive so... Yeah.
I found that the best way to kill one is to have them trapped in bollards or spikes and have X plants shooting them. DO NOT get in melee range unless with a rex, spino, giga, or another therizino. Most of the dinos I listed(all but giga) should have relatively similar levels or you risk losing them. I also seem to find an infestation of them wherever I go.
I got DESTROYED by a mate boosted level 125 while wearing Ascendant & Mastercraft Flak Armor (1500 Total Armor). Avoid these on foot at all costs. If your character doesn't have high movement speed, you probably won't survive. The Ark Freddy Krueger