yutyrannus are really good for all your boss fights, yutys are special because they can buff your dinosaurs, along with a daedon healing your dinosaurs they are great. but everything will try to attack your yuty, in dragon fight when dimorphodons spawn hop off your yuty and hop on one of your other tames. if you can do this your good to go, BUT YOU NEED TO NOT BE USING THE FEAR ROAR BY ACCIDENT!!! for so long i was making so much harder by using the fear roar like a idiot and my equally dumb tribemate could not work the daedon. man good times.