thecodont

Thân thiện

Thecodonts were ancient reptiles that walked on four legs.

Definition

1. Noun:
   • An extinct reptile of the order Thecodontia: A member of an extinct group of archosaurian reptiles characterized by having teeth set in sockets (thecodont dentition). This group is considered ancestral to dinosaurs, crocodilians, and birds.

Usage Examples

• Noun:
  • The fossil record shows that thecodonts were diverse during the Triassic period.
  • Scientists study thecodont to understand the evolution of later archosaurs.

Advanced Usage

• The term "thecodont" is primarily used in paleontological and evolutionary biology contexts. It refers to a paraphyletic grouping, meaning it includes the common ancestors of dinosaurs, pterosaurs, and crocodilians but not all of their descendants.

Variants and Related Words

• Thecodontia (n): The formal taxonomic order to which thecodonts belong.
• Thecodont dentition (n): The anatomical feature of teeth set in individual sockets, which is a defining characteristic of the group.

Synonyms

• Basal archosaur: A more modern term often used to describe reptiles from this ancestral lineage.
• Stem archosaur: Another contemporary term referring to early members of the archosaur lineage.

Notes on Meaning

• Historically, "Thecodontia" was used as a formal taxonomic order. In modern cladistics, it is recognized as an informal, gradistic term for a diverse assemblage of early archosaurs that are not part of the more derived clades like Dinosauria or Crocodylomorpha. The word itself is most commonly encountered in its noun form, "thecodont."

Học thuật

Noun

1. presumably in the common ancestral line to dinosaurs and crocodiles and birds

Từ đồng nghĩa

• thecodont reptile