Looking at my latest lumbar x-ray

I have yet to show any fusing on x-rays or MRIs, but have a litany of symptoms leading to an Undifferentiated Spondyloarthropathy diagnosis.

My low back has been more acutely painful for the past few months so I asked my rheumy on Wednesday if we could take another look. She agreed, and we got new x-rays of my lumbar spine. I'm waiting to hear from the radiologist but I did ask for copies of the images on the way out, and I just called to ask what the radiologist had to say. He said 'severe disc degeneration at L2-L3' and some other things, and we're proceeding with a new MRI next week.

So I fired up the films and took a look at L2-L3 and . . . sure enough, there is NOT the normal disc space there. Those vertebrae are squishing together. Which leads me to ask:

Does spinal fusing look different than disc degeneration on an x-ray? When two vertebrae fuse together do they assume the height of the disc in between them?

I'm wondering if what's happening is my disc dissolving leaving those vertebrae sitting on top of each other, or if those two vertebrae are fusing together and absorbing that disc or something.

They are mailing me the radiologist report so I'll have his firsthand opinion soon. I've never seen my spine look so wonky. :-/