Mountain Dragons lived in caves all over the world. They once hunted the vast herds of animals that lived during the last Ice Age, and after. Their nests consisted of rocks, and were guarded by one of the parents, who breathed fire on it to incubate them. This dragon had a blood protein similar to that of polar fish that prevented the formation of ice crystals in the bloodstream. It also went into torpor during the winter when food was at its scarcest. They performed elaborate courtship displays by flying up as high as they could before locking rear talons and falling out of the sky, and letting go at the last moment and breathing fire to finalize the courtship.
This species was a skillful and elegant flier. It was also capable of traveling long distances in search of food. This long distance flight ensured that this species could travel the globe and become widespread.
Mountain Dragons were hunted to extinction by knights, because the dragons ate their livestock. They were considered pests in the Middle Ages.
But they may still be around today.