Ok be ready for a really really long tame process.
You’ll need almost every Dino if you want to be “prepared” or if you do t have what it is at the moment leave the area and go far. It should change back while you’re gone somewhere around 15 mins just sitting next to it but much less when I left tender.
Sanguine Elixer can o my be used once taming bar has progress and while it’s in its regular form. You do have enough time to find and tame whatever it currently is but only lower levels or faster tame time Dinos. And higher level gives better taming progress. Don’t bother low level as you’ll need almost as many changes/Dino’s as a high level.
Be patient it’s gonna take a while.