I had a good one of these things and I named it Terrorgornis. I used it to find places I have yet to discover. But after I went to the desert, I got off it and it swam away chased by sharks. Is this normal!?!
Herbivore island is a safe spot to tame one of these. First, wait for one to land or fly over the surface. Then, bola it to keep it grounded. Then use a tranq bow or crossbow to knock it. Since herbivore island has a nice, relatively safe cove, you can get some fish meat from there so long as no mantas or megalodon, and feed it to pelagornis. Once tamed, you’ll need a saddle for a similar material cost of the Pteranodon’s, but Pelagornis is much better in some cases. It can swim on the surface of water, and still retains agility compared to flyers like the griffin or argent.