I agree. Sunken Civ has a file on that. Dragons are more than mere mythology, such as the Crocodile-Panther painted on pottery.
Komodo Dragons being the largest land reptiles left in isolated areas, suggest that other, larger species could have lived to relatively recent times.
The Komodo Dragon was only ‘discovered’ by Europeans in 1910!.................
During the Middle Ages, tales of struggle with dragons probably arose due to the presence of "horse eels" found *and hunted/killed) in the larger streams of the British Isles, and possibly elsewhere in western Europe. These critters are now rare, probably now (recently?) extinct, other than in Loch Ness.
In classical antiquity, dragon myths come from fossil forms remembered in Scythian folklore. The dino fossils were visible in the cliff face somewhere in Central Asia, I think even the location has been rediscovered in modern times. Adrienne Mayor's "The First Fossil Hunters" is the reference on that.
Dragon myths in other places with no solid folkloric connection with the two above do tend to be ancient, but refer to dragons in the sky, hence, likely large comets which spent periods visible in the sky, or large messy bolides coming down, breaking up, and appearing to be at least two entities struggling in battle.