Where did the stories of dragons originate from?

There is no one universal accepted theory to who started the myth. All we know is that the dragon shows up in almost every culture around the world. So how is it possible that one group created this and spread it when back in those ages, there was no way to globally communicate? It just isn't. However, one of the leading theories is that the dragon was a creation from our ancestors. It is believed to be a combination of the three biggest predators of the time. The talons and wings came from birds of prey, the scales from snakes, and the facial structure and teeth came from several large carnivorous mammals.