Labyrinthodontia

Japanese: 迷歯類 - めいしるい（英語表記）Labyrinthodontia

A general term for primitive fossil amphibians belonging to the superorder Labyrinthodontia. They are tailed amphibians shaped like a hawk or a newt, and when viewed in cross section, the enamel surface of their teeth is intricately folded, showing sinuous lines, hence the name. The heads are covered with bony plates, and there is always a small hole called the pineal fossa at the top of the head. Because of their robust skulls, they are also called pachycephalic Stegocepharia. They flourished from the end of the Devonian to the end of the Triassic. It is thought that a fish-like ancestor gave rise to the basic type of this group, the Ichthyostegales, which then evolved into the Rhachitomida in the Permian and the giant holovertebrates in the Triassic. (→Ichthyostega)

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

両生類迷歯上目に属する原始的化石両生類の総称。ハンザキやイモリのような形をした有尾の両生類で，歯の断面を見ると，エナメル質の表面が複雑に折れ込んでいて，曲りくねった線を示すのでこの名がある。骨頭は骨板でおおわれ，頭頂部には必ず松果窩という小孔がある。このように頭蓋が堅固なので堅頭類 Stegocephariaともいわれる。デボン紀末から三畳紀末まで栄えた。魚類型の先祖からこの類の基本的な型のイクチオステガ目を生じ，ペルム紀のラキトム目，三畳紀の巨大型の全椎目となっていったと考えられている。 (→イクチオステガ )

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