If you are in a tribe, do this: build stone dino gates, put them in your inventory, and ask the leader of the tribe to kick you out. Build an arena/circle and pick the andrews with a quetz and drop him in your circle. Now ask your mates to ride him. Not beeing in their tribe, means he will not attack the structures. Quetz is the only one that can pick him. Once the taming is done, get back in your tribe. This way he will not run all the map and you have him protected.