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
When taming a high level megalosaurus, you need to put down right when night starts. It sounds counterproductive because it's stronger, but it allows for maximum starve time since you will need to put it down again the following night. If you don't do it this way, you may end up needing to put it down a third time, which could very likely be the death of it since it won't regain any health over that time.
Also, tame with a friend because the megalosaurus will pick you up into its jaws which makes it very hard to do solo without dying. Your tribe mate can attack the Dino and cause him to drop you.
When raising one from an egg it is best to have it on follow that way when you're feeding it it will not sleep it will go unconscious but you can continue to feed it while it's unconscious and when it wakes up it repeats the whole process over again because if it falls asleep and you feed it you'll notice your food goes down so fast this is my best way to raise a BABY