Make a taming pen with stone gateways, 2/4 on each side, 1 on the front side, and fill the back side with one doorframe with door and the rest walls. Place a large bear trap in the middle. Trap the allo in the pen in the bear trap so that you can safely close the front side gateway (the rest should be closed. If needed, kill the others. Make a foundation with a staircase on the backside. Now easily knock at tame the allo. This probably works for more dinos but only tried with allo.
When single taming be at least level 52. Tame a Tapijara. Find a group of allosaurus. Next break one off from the pack by attacking one and leading it away. The others might follow that’s okay. Lead them to a cliff and fly over the cliff. Switch seats and begin to tranq the one you want. When you knock it out lead the others away. Go back to the unconscious Dino and begin to place meat in. Have at least ten Narco per level. The other allosaurus will almost always come back. I suggest taming two at a time. Knock out a second one. Then kill the rest as they might attack your brand new allos....... keep in mind that prime meat speeds it up by 70 percent than raw meat so go and kill some Dino’s. Good luck and happy taming! Also they might kill your new tapijara so make sure you have at least 50 percent health when going close. They killed mine.... but I had three more. Always have a backup flyers.