A long linear impression runs along the "back" of the body looking something like a chordate notochord. Cathaymyrus is related to Pikaia, another cephalochordate from the Burgess Shale.
A continuous linear trace extends along the "back" of the body, similar to a chordate notochord. Cathaymyrus shares a relationship with Pikaia, both being cephalochordates from the Burgess Shale.