有颌类包括硬骨鱼类以及软骨鱼类。
Gnathostomes include the bony Osteichthyes and the cartilaginous Chondrichthyes .
而七鳃鳗是现存最为古老的无颌类脊椎动物之一，也可以将其理解为有颌类脊椎动物的共同祖先。
The lampreys are modern representatives of the jawless vertebrates , which are thought to be the ancestor of jawed vertebrates .
有颌类