Have they?
It seems quite absurd to me that such a represented figure for thousands of years have never really existed.
Now well i am not really into the behemoth sized - flame breathing icon that has been portrayed throughout the media and especially video games, but it is not that abstract to believe that large,snake-bodied creatures with wings and possibly large fangs and claws could have existed in the past.
If you take a look at the traditional Chinese horoscope that was created some thousand years ago, it is composed by 12 animals which all of them are extremely common, except dragons. Those animals are : Dog,sheep,horse,snake,dragon,monkey,pig,bull,cock(chicken),rabbit,tiger and mouse.
That makes it even harder to believe that the majestic dragon was just the spark of the imagination of Chinese folklore.
Now the reason of their extinction is not really clear to me, but bio-historically speaking many of the large animals that existed pre-historically were quite prone to extinction.
What is your opinion on the subject?