part of part of develops_from neural tube chordal neural plate posterior neural tube (...) at some stage of its development, every chordate exhibits five uniquely derived characters or synapomorphies of the group: (...) (4) a single, tubular nerve cord that is located dorsal to the notochord (...).[well established][VHOG] AAO:0011082 TAO:0007037 UBERON:0003076 VHOG:0001383 XAO:0000250 ZFA:0007037 uberon developing anatomical structure