Yunnanozoon, interpreted as an enteropneuste hemichordate, belongs to one of them. (3). 而在其后的地层中目前还未见报道。
These characteristics are shared by brachiopods and pterobranchs (a hemichordate group) as well as by echinoderms, protochordates, amphioxus, and vertebrates. 脊索动物的祖先可能类似尾索动物的幼体，后向两个方向发展，一是经过变态，成体为固着生活，具鳃裂作为取食和呼吸器官；
The special body plan of Yunnanozoon is almost identical to that of the living enteropneust hemichordate Balanoglossus,which suggests that the earlyCambrian creature is ancestral to the hemichordates. 这种独特的身体造型与现生肠鳃类半索动物几无二致，从而表明这个早寒武世动物是地球上半索动物门中已知最古老的祖先类型。
