I suspect it's 2 point polys. Under that statistics tab, drop down Polygons, By Vertex, then hit the little + beside 2. That'll select all polygons with 2 vertices. You should be able to delete them as per normal.
I'm trying to do the backspace and it deletes my entire mesh. I can't even select the unwanted edges, it seems like they're connected, like if I select the smoothed vertex, it'll move the unsmoothed vertex as well. It's almost like it's showing the low poly cage when I smooth. Think '2' mode in Maya. Also, I'm still…