It was a theory that I had come to after being here for a while, and it was confirmed by two outside sources. At the time, we lacked in here the ability to do any real studying of it ourselves, but... personally, coming from a world that depends on mana to survive, and being aware of just how thin the mana is here, it's not a very large leap for me to come to, on that level.

Also we are aware that the Malnosso are from other worlds as well, and they also have these wings.