If you have something like a high level Spino or Rex, then go into the swamp and kill Paracers, they drop like 20 each and they’re everywhere. If you choose a tame other than a Spino or Rex, just make sure it’s tall so that Kapros can’t get you
How to get a shitload of prime: Use a flyer (preferably an argent) and pick up an ant. Then drop the ant next to a megatherium. It will go on a killing spree but never harvest the bodies. Once it has finished, go down an collect your prizes. This works best near the redwoods as the most creatures live there that will drop prime.