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.
To knock out this creature you can use a flying creature to reach a tall stone or hill that it won't be able to climb then shot it with your tranqs, if and when it suits spikes at you move back slightly to dodge them. Good luck.
You can knock out low levels with something as simple as the boomerang. Just try not to get hit by too many quills. One or two per barrage shouldn't be too bad. Anything beyond that could be certain death
When taming it with meat starve it and make a perserving bin place in the back of foundation so you can fit yourself in the tent then make sure you have sparkpowder and perserving salt because they eat food every 50 hunger for meat so put in perserving bin and spike around it for easy tame
Put a floor on ur paracer with walls and a celling then put gate at back with ramps leading dwn stick 3 or 4 of these on back of paracer to carry say 4x 500 in carryweight of wood but a paracer can hold say 1500 only 1000-1200 will be used depending on the weight of thornys
Its best to knockout from up high where you are out of reach as it has quick attacks and decent damage. It does have a ranged topar attack as well but is easily dodged. Tranq darts are always the best option but if not available, delay your shots with tranq arrows by 2 to 5 seconds to allow the topar to build all they way. That way the arrows dont accidentally kill it.