agnatha a 无颌类 ; 动物[1]
The Galeaspid is one major group of Agnatha in the Middle Paleozoic, and is mainly distributed in China and North Vietnam.
盔甲鱼 类是古生代中期化石 无 颌 类的主要 类群，其分布主要限于我国境内以及越南北部。[1]