Found in western pennsylvania...all sizes and shapes from small pieces maybe 2x3in. thru my largest which is probably 18 in. across 10 in. wide and 8 inches thick weighing at least 35lbs.
at certain Points it looks like Intestine , but other points it looks like it's connected
like a T so I'd say not.
Buy Responding so I can keep watch & hope for an answer
at first I thought trace fossils such as worm burrows, someone else said trilobite burrows I've got them listed for i.d. on other sites too I'll post any opinions I get frome them too. thank you