They have about theri aggro range and their first attack is pretty much always spikes so use this to your advantage. Pump up stamina, health and damage for the best thorny dragon. Also drink a stimulant or take stimberrys just to be safe. Their also quite slow but still proceed with caution cus once your knocked out your dead.
If you are going to tame one of these with no dinos, be sure to upgrade your movement speed and get tranqs. When you see it whip its tail forwards move to the right you will dodge the shots. This worked for me.
Did you know that thorny dragons when they hit other dinosaurs 🦖 with their thorns on their tails, it actually knocks out the dinosaurs 🦕 not kill them, it mite kill the but most likely not and it takes from like 540 to at least 600!!