Do Balrogs Have Wings?

[Folwren]

The sound of hoofs stopped. As Frodo watched he saw something dark pass across the lighter space between two trees, and then halt. It looked like the black shade of a horse led by a smaller black shadow. The black shadow stood close to the point where they had left the path, and it swayed from side to side. Frodo thought he heard the sound of snuffling. The shadow bent to the ground, and then began to crawl towards him.

Oh, well, if Tolkien did it here, then he may well have done it at the Bridge -

Everyone knows that the Nazgul wasn't a black shadow. But he calls it so several times in this passage (which Mister Underhill so kindly dug up for our use) - after saying it 'looked like' shadow. Couldn't it therefore be the same with the Balrog? The shadow looked like wings...so instead of saying shadow again, he used wings in the quote:

... and suddenly it drew itself up to a great height, and its wings were spread from wall to wall ...

Stab in the dark there...tear it apart if you like. It's only half baked.