The middle zone of the mesoderm of a chordate vertebrate embryo, from which excretory tissue develops.
中胚叶节脊索类脊椎动物胚胎的中胚层的中间部分，…
2
Beginning. This genus is considered a chordate, and the phylum Chordata includes fish, mammals and man.
的注意。因为这一类动物属于最高的脊索或半脊索动物，包括鱼类，哺乳类动物和人。
3
The origin of vertebrates has always been a core question in evolutionary biology. It is well accepted that vertebrates and invertebrate chordate derived from a common ancestor.