Build 5 stone dinosaurs gateways in a circle with 2 pillars in the middle of each doorway except 1, lead the desired tame through the gates with 1 pillar and as he's stuck, put one on top of the first pillar trapping him.
Use a tapajara or a quetezl for this and sit above the tame and tranquil it and then kill the others or do the same thing and kill prime animals with the bird or arrows and use the bird to get the prime or a pick and being extra narcotics
The best option for taming these is too have 3 or more at once, lure them into a taming chamber (you can easily make out of wood) then have a ramp going up the side of it to get to the top, shoot them all in the head. Then you're able to tame all 3 at once making you highly dominate.
If you are looking to get an Allo. Go to Lat. 40 Long. 11. They dont always spawn here, so it may take a while. Make a Raft with a wood or stone fountain 2x2 and then make a 1x2 tower that is 3-4 tall. Keep the Allos in the water. I made the mistake of making my tower 2 high. They almost got me. Hope this helps. Like if u Found useful so more ppl will see. =)
Someone said it takes more arrows to KO one than the app said. I just found a lvl 13 Allo, app said 11 tranq arrow w/ crossbow to body, and I put all 11 arrows into its body ( mainly because it was squirming all over the place in the enclosure) but 11 did the trick after letting it set and build up over time. App is accurate if you ask me
They don't take triple damage to the head with tranqs. Shot 28 darts with 180% damage in its head while trapped until it went down. So don't worry about getting headshots, just fire away anywhere on its body like its a Rex.