The only logical explanation from all of these similar accounts (when most of them weren't seen by others) is that there were, in fact, some type of large lizard-like creatures living in those places...
Okay, I'll bite..WHY?
because people in Asia, Europe, Africa, & South/North America ALL saw these things...all the accounts are similar enough to assume that there probably really was something there...
People in all of those countries claim to have seen Bigfoot, UFO's and Elvis.
yes, and most of the people claiming those things have heard the stories others told...The people in South/North America had never heard of European/Asian dragon stories...
and the dragon stories in Asia and Europe were early enough to assume that they probably hadn't travelled far enough for them to be copied from other accounts, too...
same with some of the stories from Africa...
also, are there stories in Australia? I'm not sure, but if there are, again, far enough away (and out of contact) to assume they had never heard the dragon stories from other cultures...
so, how are all the stories relatively similar if the things never existed?