labyrinthodont

fossil tetrapod

Also known as: Labyrinthodontia, Stegocephalia

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 30, 2026

Quick Summary

The term "labyrinthodont" refers to an extinct group of early tetrapod vertebrates that lived during the Carboniferous and Permian periods, approximately 359 to 251 million years ago. These animals are considered precursors to modern amphibians and may have been ancestral to all terrestrial vertebrates.12

A key characteristic of labyrinthodonts was their unique tooth structure, known as a "labyrinthine tooth." This type of tooth featured infolded enamel, creating a grooved and reinforced structure. Labyrinthodonts varied in form, often resembling salamanders or crocodiles, and are thought to bridge the evolutionary gap between lobe-finned fishes and the earliest reptiles.1324

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

4 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

amphibian
Annotated classification
(adelospondylians)†Order Aistopoda(aistopodans)Upper Mississippian to Lower Permian. Lepospondylous vertebrae; elongate body with reduced or no limbs; and forked single-headed ribs.†Order Nectridea (nectrideans)Lower Pennsylvanian to Middle Permian. Lepospondylous vertebrae; elongate body with reduced well-differentiated
Read More
(adelospondylians)†Order Aistopoda(aistopodans)Upper Mississippian to Lower Permian. Lepospondylous vertebrae; elongate body with reduced or no limbs; and forked single-headed ribs.†Order Nectridea (nectrideans)Lower Pennsylvanian to Middle Permian. Lepospondylous vertebrae; elongate body with reduced well-differentiated
Read More

labyrinthodont
Labyrinthodont is also an archaic name for any member of the subclass Labyrinthodontia, an extinct group that served as a precursor to the amphibians. Labyrinthodonts lived during Carboniferous and Permian times (about 359–251 million years ago) and may well have included the ancestors of all…
Read More
Labyrinthodont is also an archaic name for any member of the subclass Labyrinthodontia, an extinct group that served as a precursor to the amphibians. Labyrinthodonts lived during Carboniferous and Permian times (about 359–251 million years ago) and may well have included the ancestors of all…
Read More