Although wyvern's make more sense, I’m wondering if it was possible from the thousands of 6-limbed mutation failures that somewhere along the line there was a small success that we never discovered. From the popular belief that many amphibian variations have had 1 or more extra sets of limbs this may have happened.

If this is true, it would be surprising that nothing has yet been discovered, but I don't doubt for a second that what we have discovered is really only scratching the surface of the number of species or who knows, possibly even right through to a number of classes that once lived. Some number of classes possibly won’t ever be discovered considering the specific conditions in which fossilization needs in order to take place.

We all know that it’s possible that even if they did once live, what’s to say that any evidence will ever be discovered? It’s a mass generality among humans that “we’ve been here long enough and discovered enough know it all by now”, which is rather narrow-minded of us to consider that we have found many of the species or classes that existed over 550 million years (of complex life) from the few hundred years that people have been recording fossils of extinct animals.

It’s still enjoyable considering the possibilities of what may or may not have happened. Over 1 million species of insects found it easier existing with 6 legs and some with 2 additional wings rather than 4 limbs and no wings, why wouldn’t any other species benefit from flight and greater stability?

Flight is thought to have evolved from (generally) 1 set of wings that eventually forms into wings. In vertebrates that have achieved flight (not just gliding), the known cases have been in pterosaurs, bats and birds, 2 of these using living tissue to form the wing between digits in bats 4 digits with membrane between all digits and the body form the wing, 1 digit was kept as a type of “grappling hook” to move around while not in flight.

Pterosaurs had 1 elongated finger with the membrane between the 4th digit and the body, while 3 other digits remained and were apparently able to grasp things. 1 digit was lost through evolution must the same way marine mammals lost their hind limbs.

Historical imagery seems to show that dragons would have had a similar wing configuration as bats do today, with the exception being the “hook” digit (in most situations).

I don't know.. it's all speculation, but it's still fun none-the-less.. feel free to add something to broaden my view on this subject..

Plus I didn't bother proof reading this and most of what I said was probably incorrect.. :slaps forehead:

And if you’re wondering, yeah I was rather bored today at work with my ponderings.