七鳃鳗类
- 网络lampreys
七鳃鳗类-
原始的无颚脊椎动物；七鳃鳗；八目鳗类鱼。现已灭绝的无颚有甲鱼类或鱼状脊椎动物；其分类尚不明确。
Extinct group of armored jawless fishes or fishlike vertebrate ; taxonomy is not clear .
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鳗鲡状的脊索动物超类，没有咽喉和骨盆鳍；七鳃鳗；八目鳗类鱼；一些已灭绝的种类。
Superclass of eel-shaped chordates lacking jaws and pelvic fins : lampreys ; hagfishes ; some extinct forms .
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七鳃鳗作为无颌类脊椎动物的代表，拥有着最古老的适应性免疫防御机制。
Agnathans , represented by lamprey , are agreed to be the oldest vertebrates possessing the adaptive immune defenses by now .