...繁茂,海洋中无脊椎动物茂盛,甲青鱼等在泥盆纪后期衰退,代之而兴的是具有原始颌骨的棘鱼(Acan-thotll)和盾皮鱼(Placoderms)。泥盆纪还出现了总鳍鱼(Crossopterygian),是动物从水登陆的先驱。
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placoderms s 盾皮鱼纲
以上来源于: WordNet
N any extinct bony-plated fishlike vertebrate of the class Placodermi, of Silurian to Permian times: thought to have been the earliest vertebrates with jaws 盾皮鱼
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