Thanks for the tips. I got a 155 egg by using this plan.
Step 1: Bring spinos to drake trench.
Step 2: Steal an egg from one of the nests outside the main trench to aggro and kill the drakes, Make sure the trench is clear before you enter. I did this so I wouldn't have to abandon my spinos in the trench. 2 of my spinos jumped in anyways but they helped get the egg.
Step 3: Find a high level egg, since if you're following this plan the trench should be clear you shouldn't have to worry about drakes.
Step 4: Get back to your spinos and go home.
This was done with 4 spinos that were leveled up to have 20k health and dealt greatly varying amount of damage. The only problems I ran into was that they kept getting stuck and that 2 of them jumped into the trench. Otherwise the run went fine.