Hey all, just started playing Ark. Recently an Alpha Raptor spawned by my base and I couldn't kill it with typical methods (I didn't realize how tough they were!). (I hadn't even tamed anything other than a trike yet.) I then built a cage and tried to lure it in. Of course it's too big, however.... I managed trap a wild Alpha Raptor in a small cage! https://youtu.be/OlzvnTDd5OI
Let me know if this works for you too or was just a fluke/glitch!