Dragons are such a great group of living beings that experts are in doubt whether they should be considered as an order or a subclass. In fact, the name Dragon encompasses a number of animals that share some common characteristics.
    To allow sufficient time for great diversity and complexity of dragons to emerge, the first ancestors of dragons must had come since the Carboniferous period, about 300 million years ago, at the emergence of the first reptiles, soon differentiated into a lineage that would give rise to mammals and another that would create dinosaurs and birds later. The ancestors of dragons ar