I was Taming a lvl 100 of these when after a while I went above to my argy to go and tribute the artifact I had, Leaving the megalosaurus with alot of torpor. When I came back, POOF it was gone. I think when you leave the cave EVERYTHING resets. Oof.
Tame the mega during the day! It is extremly slower during the day due to wanting a rest. It is a very strong dino, it has been tested to be even stronger than the allo! Be careful if you tame it at night ;) caw