Labyrinthodontia


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Labyrinthodontia

[‚lab·ə‚rin·thə′dän·chə]
(paleontology)
A subclass of fossil amphibians descended from crossopterygian fishes, ancestral to reptiles, and antecedent to at least part of other amphibian types.

Labyrinthodontia

 

the largest superorder (subclass in the opinion of some scientists) of ancient amphibians. The laby-rinthodonts lived in the late Devonian period and in the Triassic period. They are characterized by a relatively large skull, the roof of which forms a continuous covering. The tooth dentin has a folded structure (hence the name of the superorder). In external appearance these amphibians resembled the crocodiles (Platyops) or the salamander (Dvinosaurus), sometimes reaching 5 m in length (Mastodonsaurus). Most lived in marshy forests, in lakes, and in rivers; some lived on the shores.

Labyrinthodonts serve as index forms for continental Upper Paleozoic and Lower Mesozoic deposits. There were more than 30 families comprising 100 genera. The animals are known from European, Asian, and North and South American deposits.

REFERENCE

Osnovy paleontologa. Zemnovodnye, presmykaiushchiesia i ptitsy. Moscow, 1964.