My bootleg way to tame it is to lead a microbe swarm to it then leave the area. depending on the swarms level you'll only need one to tame it, to check the level of the swarm use the button that brings up the hud for using orbital camera and thrird person HLNA will then show you. The best way I've found to bring the swarm to it without trouble is to eat a cactus broth. Once the turtle is tamed it'll show in your tribe log afterwards you just need to go back to its last known location and find it.
They have patched the render range range so ignore any tips that say to leave render as it will no longer. Guess I’m stuck with the turtles I have, I’ve spent three hours trying to take one of these things and had it walk out of the water which reset it taming! It was at 80% that time. Never got it above 20 after that. What he for the saber tooth salmon that spawn to kill the swarm if they bite the turtle it resets to zero and you start over. Extremely frustrating way to tame a creature. I would like to beat whoever came up with this idea.
Got one to 60% on one parakeet school. Noticed a salmon or coel following the school and killing it. Killed the fish and literally watched one more spawn and do the same. No successful one swarm tames yet but I'm going to keep trying
Lead it into a line of stone behemoth gates and close a gate behind it and it will be trapped or you make a square box of Dino gates and nothing can mess its taming up while it’s being tamed so up this!!!!!!!