Tame them by getting their eggs. Use a whip while you're grappled to a flyer. They need five fireplaces to hatch. It doesn't take that long for them to grow, but to hatch them it's thirty minutes. They can be found easily on the white cliffs along with their eggs. I don't care if you like this or not I just wanna give tips.
These guys can be carried by a Procoptodon as a baby so get 2 mate boosted procoptodons put deinonychus in the pouch and imprint them and they will get 2x im printing instead of getting 1x when Imprinted from a character.