UCMP MYSTERY FOSSIL #35 is . . .
Scaphopods

These particular scaphopods, or “tusk shells,” are from the Miocene of Baluchistan, Pakistan, though the earliest known scaphopods have been found in Devonian-aged rocks. Scaphopods are molluscs that differ from most molluscs in that their tubular shells have an opening at both ends, not just one end. The adults spend their lives buried in the sea floor sand or mud, heads downward. Find out more about scaphopods here.