I like the idea of letting the cultures of each kingdom have their own names for the dinos. For example, the culture that I created have their own language and so the dialect would be a lot different than what your kingdom's culture might call them. I do have an idea for a universal name for pterodactyls and that is "Teras" which is short for Teravaes which means "Sky Demons" in Echlai, the language that I'm developing for my character's people in this role play. It'd be an interesting foreshadowing since the people of this time don't know the real names of the dinosaurs.

I also like the idea of using Titan, but I think that carnivores and herbivore dinos should be called two seperate things. Rogue Titan could be the large carnivores and just Titan or Gentle Giants for the large herbivores. I think the most interesting thing as you stated (and I'm still thinking of) is what we could call all dinos in general. Should be something unique just like TWD came up with the name Walkers for zombies. Maybe something like Demon Beasts or Devil Monsters. Those are just some I threw out of my brain real fast.