I couldn ' t find the traits to phylum chordata in the book 这本书上找不到门科，脊索动物类
2.
Peacocks are classified in the phylum chordata , subphylum vertebrata , class aves , order galliformes , family phasianidae 孔雀被认为是脊索动物类，脊索动物亚门，鸟类。
3.
Amphioxus , an existing animal that belongs to the phylum chordata , subphyla cephalochordata , is always regarded as the invertebrates which is the nearest to the vertebrates . it has great sense on the research of how the vertebrates develop from invertebrates 长久以来，文昌鱼一直被认为是现存的与脊椎动物亲缘关系最近的无脊椎动物( stokeandholland , 1998 ; zhangetal . , 2001 ) ，在脊椎动物如何由无脊椎动物进化而来这一著名的生物学难题中占据重要的位置。
