After 2 failed attempts, on xbox, the only way to raise one up is to use a daeodon. I had to kill about 17 brontosaurus to feed the daeodon and to bring up the food bar. Each pass of passive healing uses about 2000 food. You have to watch this closely. Mutton fills food bar by 100 and raw prime meat fills it by 50 whereas regular raw meat fills it by 10. It has taken hours. Also remember to give the magmasaur some stimberries so that the torpor does not go all the way up. All this is very important. I did my first marmasaur on January 4, 2022