I'm not sure about Marco, in all honesty. I don't think he used it- but even if he did, that's beside the point. Obviously, Marco is not Beast Pirates and nor is he one of the main antagonists of this arc. He's also a special mythical who doesn't function like regular zoans and ancient zoans. Oda even highlighted Jack's Hybrid in a fight vs one of the non-mcs. Let alone King'
If you think Marco used hybrid you must think king used his too.
99% of the time Marco is using partial transformation : wings only or claws only or wings and claws.
here king clearly used an other form with his wings :
Maybe King can do other things with his hybrid with talons or shit but this really look like a Marco type of hybrid for me : choosing to transform some parts depending on the situation. And King even has that pteranodon thing on the head while being in that form.