The basis for the concept of ‘dragon’ was largely fossil evidence. People were finding large skeletons of a certain type, and postulating that there existed a type of creature to whom the fossils belonged.
The term “dinosaur” was adopted in the mid-19th century by paleontologists to describe a kind of reptile, based on somewhat similar fossil evidence but situated in a different theoretical context.
Yet, imagine: how would we think of dragons if the people who adopted the name “dinosaur” had decided instead on the name “dragon”?
Would we say that the old ‘dragons’ never existed, being supernatural, but new ‘dragons’ existed? Or would we, rather, say that dragons existed, and we used to have a mistaken conception of certain aspects of dragons? I.e., would we say that we have refined our concept of just what dragons were like?
Consider: the concept ‘dinosaur’ has undergone various theoretical changes: the exact time when the dinosaurs were alive, what they looked like, whether they were warm-blooded, their social behaviours, and so on. Yet, it seems odd to say after every conceptual change: the old ‘dinosaurs’ didn’t exist, but the new ‘dinosaurs’ do. Rather, we say: before we had the conceptual refinements, we were referring to creatures that existed, and we now have a better picture of exactly what they were like.
Why can’t the same argument apply to ‘dragons’ into ‘dinosaurs’? It seems the naming convention is somewhat arbitrary. To be sure, when significant conceptual changes are made, people often pick a new name for something. Yet, they might not. Regardless, the name doesn’t seem to be what’s important to the reference of a term.
The question of reference, however, obscures another issue: we pick new names because they are useful. In particular, they help in gaining a certain sort of conceptual clarity. The point is that the concept ‘dragon’ is significantly confused. The concept ‘dinosaur’ is (we believe) less-so. We could simply transform the concept associated with the word “dragon” into the concept we now have associated with the word “dinosaur.” In the context of discovery, though, the introduction of new ‘pegs’ on which to hang the conceptual hooks is a significant practical consideration.