I found this years ago - ran across it in a box recently. It is kind of a medium grain sandstone, my collection recollection is that it would have been in Pennsylvanian strata, a thin (maybe 10 inch) sandstone overlying a small coal layer. I always recalled it as a bit of a mystery. It was before the internet - so we were all a lot slower and dumber then. I always assumed it was some type of a trace fossil - a filled in burrow? BUT - the main thinner segmented tube presents a faint flattened oval or crushed tube when looking at the end. Hard to get a picture of that. Also - it appears to lay on a larger rounded faintly segmented structure. WHAT IS THIS - Thoughts??