I built 4 Behemoth Gateframes and 4 Behemoth Gates. Put them in a square with a little gap in between each Gateway to be able to go in but nothing gets out. Use an Argy to lure them in and close gate behind it. Then knock it out.
If you use the bear trap strategy which is if you lead it into a Dino gateway that is shaped in a triangle and with a bear trap in the middle (Large Beartrap) and when it is stuck you must put a dinogate behind it to trap it and then knock out. (hope this helped and "If" I win could it be an Xbox voucher, thanks.)