We grabbed ours with our quetzal and held it for a person to shoot. We tried to tame a few from the ground with bolas and darts or clubs but they always died. We tamed 4 by holding it with a quetzal and shooting darts (arrows do to much damage) and we didn't lose a single one! On the center there are a few in the woods by blue ob, but the redwoods is covered in them. Wakes up hella fast so bring narcotics. Good luck!
BioToxin seems to be more effective keeping it knocked out,Just farm up jelly fish with a cross bow, if your on Scorched earth have fun sitting there with narcotics for a while being paranoid about the boulders getting up to smash you.
Do yourself a favor. Start with a magnifying glass so as not to kill it, and then once it's out, quadruple the time and narcoberries necessey to keep it unconscious. Calculator is really off when it comes to dinos whose torpor rapidly drops.