I think this is a Porcupine Bezoar?I just got this Rock or fossil a week ago and i trying to find out what it could be , on the last 3 photos i use a digital microscope to get closes . At the last photo is inside and shell out side . Thank you for your time. View attachment 1701867 View attachment 1701868 View attachment 1701869 View attachment 1701870 View attachment 1701871 View attachment 1701872