物存在同源的 CNE 之外，与尾索动物 (Urochordate)海鞘 (Ciona intestinalis)和棘皮动物 (Echinoderm)海胆 (Strongylocentrotus purpuratus)之间也存在同源 CNE。[1]
n. primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva[1]