Never tranq it to calm it. It will continue to sleep for the rest of its life. Mine is sleeping since 56min, and i can't wake up with stimulants cause it's glitched and i can't acces to it's inventory. Happy 150 Hyaenodon tame failled.
Normally you can't tame the pack leader, so just get a pteranodon or argy, pick it up and drop it in a large area (like a separate section of your base). When you take it away from the rest of the pack, it removes its 'pack leader' title, allowing you to tame the highest level hyena of that pack.