But even if he didn't
create dragons he most probably bred them from... I don't know what creatures. Because when Glaurung (the first of the uruloi) first faces elves, he's yet young and scarce half-grown. And he seems unknown to elves: 'Few forsaw the full meaning and threat of this
new thing'. And Morgoth was ill-pleased that Glaurung had disclosed himself too soon.
I think it proves that dragons were not just tamed by Melkor, But they were something really new that emerged from Angband.
