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词汇 Labyrinthodon
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释义

Labyrinthodon

中文百科

迷齿亚纲 Labyrinthodontia

(重定向自Labyrinthodon)
Cross-section of a labyrinthodont tooth

迷齿亚纲(学名:Labyrinthodontia)为两栖纲之下已灭绝的一支,见于泥盆纪后期或石炭纪早期,兴盛于石炭纪至二叠纪。旧属坚头类,现时重成分类作迷齿亚纲。因牙齿基部,包围齿髓腔的珐瑯质和齿质,形成复杂如迷路的褶襞而得名。主要为水栖或半水栖。

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英语百科

Labyrinthodontia 迷齿亚纲

(重定向自Labyrinthodon)
Cross-section of a labyrinthodont tooth
Early (ichthyostegalian) labyrinthodont.
Skeletal reconstruction of Acanthostega, an early (ichthyostegalian) labyrinthodont.

Labyrinthodontia (Greek, "maze-toothed") is an extinct amphibian subclass, which constituted some of the dominant animals of late Paleozoic and early Mesozoic eras (about 390 to 150 million years ago). The group evolved from lobe-finned fishes in the Devonian and is ancestral to all extant landliving vertebrates. As such it constitutes an evolutionary grade (a paraphyletic group) rather than a natural group (clade). The name describes the pattern of infolding of the dentin and enamel of the teeth, which are often the only part of the creatures that fossilize. They are also distinguished by a heavily armoured skull roof (hence the older name "Stegocephalia"), and complex vertebrae, the structure of which is useful in older classifications of the group.

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