Anaspida
Học thuậtThân thiện
Definition
- Noun:
- An extinct order of jawless vertebrates: "Anaspida" refers to a specific taxonomic order of primitive, extinct fish-like vertebrates that lacked jaws. These were early aquatic animals, typically characterized by their bony armor and considered part of the broader group of jawless fishes (Agnatha).
Usage Examples
- Noun:
- Fossil evidence suggests the Anaspida were small, armored fish that lived during the Silurian and Devonian periods.
- The Anaspida are an important group for understanding the early evolution of vertebrates.
Advanced Usage
- In paleontological context: The term is used technically to discuss evolutionary biology and fossil records.
- The phylogenetic position of the Anaspida among jawless vertebrates is still debated by researchers.
Variants and Related Words
- Anaspid (noun): A member of the order Anaspida.
- The anaspid fossil was remarkably well-preserved.
Synonyms
- Jawless fish (Agnatha): A broader superclass that includes Anaspida and other orders like Osteostraci.
- Note: "Agnatha" is a more general term, while "Anaspida" specifies a particular order within it.
Related Terms
- Osteostraci: Another order of extinct jawless vertebrates, often studied alongside Anaspida.
- Heterostraci: A different order of armored, jawless fish from the same era.
Noun
- extinct order of jawless vertebrates