So, i found a weird structure in a piece of jurassic limestone. It is cylindrical and roughly one cm in diameter, enters the stone on one side and leaves on the other. Under the microscope, you can see particles of limestone/calcite at the inner walls, partially being held in place by some hair-like fibers. Is this a fossil, and if yes, what kind of animal or plant could this have been? Or is it something anorganic?
I'm new here, please tell me if i forgot to mention anything important. Thanks in advance.