It isn't a matter of "species boundaries," which aren't even really rigidly defined, so much as time, complexity and information compression.
It doesn't seem likely that whatever primitive mammalian ancestor eventually evolved into primates, and then into humans, carried within it a coherent enough visual and behavioral memory of dinosaurs to have survived so many generations of mutation, eventually informing the modern idea of "dragons" as winged reptiles.
And again, it isn't even true that there is a cross-cultural concept of "dragons" to begin with. It's a eurocentric myth, in that it assumes a Western concept of a "dragon" to be the default, and ignores any other cultural context in order to fit their mythologies into that mold.
It doesn't seem likely that whatever primitive mammalian ancestor eventually evolved into primates, and then into humans, carried within it a coherent enough visual and behavioral memory of dinosaurs to have survived so many generations of mutation, eventually informing the modern idea of "dragons" as winged reptiles.
And again, it isn't even true that there is a cross-cultural concept of "dragons" to begin with. It's a eurocentric myth, in that it assumes a Western concept of a "dragon" to be the default, and ignores any other cultural context in order to fit their mythologies into that mold.