Found this in 410m yo limestone along with crinoids, lots of coral including rugose (horn and colony), and trilobites. Thought it was another rugose until I cleaned it up, but the ‘horn’ is pointy in both ends, there looks like a moulding of soft tissue off one side (reminds me of an oyster or muscle), and the shape of the whole rock matches the shape of the ‘horn’.... Not sure! Thanks for any ideas! #fossil