Prehistoric Dragon

Cretaceous dragons were the largest flying animals ever to have lived. The prehistoric dragon descended from a group of aquatic or semiaquatic dragons that occupied coastal swamps approximately 200 million years ago in the late Triassic, which gave rise to both marine and terrestrial species. Initially, the terrestrial dragons were quadrupedal, running on all fours and unable either to fly or to breathe fire. One species evolved the ability to run bipedally, on its hind legs. This enabled further evolution of the forelegs, which were no longer used for standing or running. These limbs eventually evolved into wings, making flight possible. This parallels almost exactly the evolution of birds with flight ability from small, bipedal dinosaurs.

At some stage — and there is no fossil evidence on this point to date — dragons harnessed active gut bacteria to produce hydrogen. This made it possible for dragons to escape the size restrictions of bird and bat flight, and to evolve into the largest flying animals ever to exist, challenging one of the largest known carnivore on land at the time, the T. Rex. Subsequently, dragons ingested inorganic minerals, such as platinum, sparking the catalytic ignition of its gut-produced hydrogen. The potent weapon of fire-breathing was added to the dragon's armory: the prehistoric dragon had arrived.