Dragons were real? read befor you badmouth this is all theory?

history hints at dragons from civilizations thousands of years ago and most never had contact with each other. and in an ancient church a dragon is shown fighting a monk. is it possible that these were prehistoric and light boned(reason why no fossils are found) creatures had survived the extinction and the ice age as alligators did but died due to the religious hunting of dragons and humans building into their territory? what is your theory/opinion on dragons possibly being extinct animals that had no magic what so ever?