On PS4 I tried to test it's obsidian gathering since it is "Rank 1", well all it was gathering was stone. So I went to another saying maybe something was wrong, NOPE it does not gather obsidian. Just use an Anklyo for that.
Build a 3x3 platform, then build a metal/stone hatchframes on top and put a ramp leading up to them. Build walls up top and lure Doe onto top level. Go below and shoot underside through hatchframes with tranq darts, done
Shoot for the head or tail with trans arrows and crossbow combo. When it rolls into a ball leave the area and keep an eye on them with a spy glass. Wait for it to start moving before approaching and shooting again. For high level ones, use a magnifying glass to check the torpor lvl while it's in ball form. Takes several rounds to get them knocked out. Don't waste your time trying to apply torpor while it's in a ball. Good luck.
I was flying my pteranodon, and i saw a lvl 27 rex pick on one of these lil cuties. He curled up into a ball, and took no damage, so combined with its mining capabilities, this lil guy is perfect for the mountains, as they have incredible defense, and mining capabilities.