Where do dragons come from and why do they persist even as they transform in imagination across culture and time? The question comes into focus once again with a show in Paris of magnificent artefacts and artworks from China and beyond that feature these most enigmatic of supernatural beasts.

One clue as to their origin may be that, while they resemble different animals in their extremities — in China, these typically consist of the ears of an ox, the claws of an eagle, the scales of a carp, the antlers of a stag and the head of a horse, camel or demon — the core of their being in many cultures is that of a snake.

There is an abundance of speculation as to what sights in the natural world gave rise to the idea of dragons. In his monumental environmental history of China The Retreat of the Elephants, Mark Elvin suggests that one real-world inspiration may have been the reticulated python, a partially aquatic beast that can reach eight metres in length or even more. Sightings of these giant snakes, together with their bones and the occasional discovery of the bones or fossils of other creatures of prodigious size, including dinosaurs, may have provided some of the earliest and most enduring evidence for dragons’ supposed existence. The biologist Stephen Secor hazards that hydrogen gas escaping through the mouths of the rotting carcasses of these and other snakes could easily have caught alight at the campfires of human hunters, giving rise to the idea that they sometimes breathe flame.