This is just a couple of centimetres fragment (the head end) of an acorn worm from the family Ptychoderidae (left image). It was collected from 644 m deep in the Tauranga Canyon, Bay of Plenty, and is a member of the phylum Hemichordata. These animals make characteristic spiral tracks in the mud on the seafloor as can be seen on this seafloor image from the Challenger Plateau (right image).
