You can pretty easily tame a low level one early on. I used one fertilized trike egg and a sarco for tanking some hits from the adult gigantoraptor. Don't even need ghillie.

Clean up foliage near and under the nest, then place the fertilized egg on the ground away from the nest. Wait for the parent to walk towards the egg and then jump in the nest. Do one round of the minigame with the baby gigantoraptor, then get out of the nest and run to pickup the fertilized egg from the ground before the adult gigantoraptor devours it.

If you get aggro run to and mount your tame that you parked on passive to the side. The adult gigantoraptor will soon get bored and return to the nest. Now you can repeat the same process until you have tamed the baby gigantoraptor and pick up the fertilized egg one last time and hatch it if you'd like.