基本解释原睡物类同根派生 protochordates相关词英汉例句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；protochordates更多例句