Definition

Noun 1. An extinct order of amphibians: Labyrinthodonta refers to a large, diverse, and extinct group of early amphibians that lived from the Devonian through the Triassic periods. They are characterized by a robust, often crocodile-like or salamander-like body, a solid and flattened skull, and teeth with a complex, folded internal structure (labyrinthine dentine).

Usage Examples

• Noun:
  • Fossils of Labyrinthodonta provide crucial evidence for the transition of vertebrates from water to land.
  • The heavy, flattened skull of Labyrinthodonta distinguishes them from modern amphibians.
  • Paleontologists study the conical teeth of Labyrinthodonta to understand their diet and ecology.

Advanced Usage

• Scientific Classification: The term "Labyrinthodonta" is primarily used in paleontology and evolutionary biology. It is often considered a paraphyletic or polyphyletic group in modern cladistics, meaning it includes a common ancestor but not all of its descendants. Contemporary literature may use more specific clade names like Temnospondyli.
  • While historically significant, the grouping Labyrinthodonta is now seen as an informal category encompassing several early tetrapod lineages.

Variants and Related Words

• Labyrinthodont (adj/n): The adjective form describing characteristics of this group, or used as a noun to refer to a member of it.
  • The labyrinthodont tooth structure is a key identifying feature.
• Temnospondyli (n): A major, well-defined clade of extinct amphibians that were historically placed within Labyrinthodonta.
• Stegocephalia (n): An older, broader term sometimes used synonymously with Labyrinthodonta to refer to early amphibians with robust skulls.

Synonyms

• Stegocephalians (in historical/older scientific contexts)
• Early amphibians (general, non-technical)
• Stem-tetrapods (in some evolutionary contexts, though this is a broader category)

Related Phrases and Terms

• Labyrinthine dentine: The specific, intricately folded structure inside the teeth that gives the group its name.
  • The name Labyrinthodonta is derived from the labyrinthine dentine in their teeth.
• Solid flattened skull: A key anatomical feature (anapsid or temnospondyl skull) common to these animals.
• Devonian through Triassic: The geological time range (approximately 419 to 201 million years ago) during which these animals existed.

Noun

1. extinct amphibians typically resembling heavy-bodied salamanders or crocodiles and having a solid flattened skull and conical teeth; Devonian through Triassic