This eye opening documentary from A&E asks the question "Were Dragons real?". With cultures separated by geography and the flow of time all having similar accounts, it's indeed possible that Dragons may have once existed.
Thanks to NETFLIX here is a summary:
Dragon tales have existed among different cultures for centuries. This program explains the appealing lore of the winged, fire-breathing beast as it traces its history. Whether you dream of slaying or befriending the mighty predator, there's no escaping the impact of these imaginary creatures on society. The influence of dragons is evident in art, science and religion both past and present. How has this mythical creature endured?