Definition

Noun: 1. An extinct taxonomic group of armored, fish-like vertebrates: "Suborder Cephalaspida" refers to a specific scientific classification for an extinct order of jawless vertebrates. They are characterized by their heavily armored head shields. The exact taxonomy and relationships within this group are considered uncertain or debated by scientists.

Usage Notes

• This term is used exclusively in scientific contexts, specifically in paleontology (the study of fossils) and vertebrate zoology.
• It is a formal taxonomic rank ("suborder") within biological classification.
• The note that "taxonomy is not clear" is an integral part of the definition, indicating that its placement and the list of species it includes may vary between different scientific studies.

Examples

• Noun:
  • Fossils of the suborder Cephalaspida provide important clues about early vertebrate evolution.
  • The relationship between Suborder Cephalaspida and other early jawless fish is still a subject of research.

Advanced Usage

• The group is often discussed in relation to other early vertebrates like ostracoderms.
• In some taxonomic systems, Cephalaspida may be treated as equivalent to or overlapping with the group "Osteostraci."

Variants and Related Words

• Cephalaspid (noun): A member of the suborder Cephalaspida.
  • The cephalaspid had a broad, flattened head shield.
• Osteostraci (noun): A frequently used synonym or closely related taxonomic group in scientific literature.
• Ostracoderm (noun): A broader, informal term for several groups of armored, jawless fossil fish, which includes the cephalaspids.

Synonyms

• Osteostraci (in many taxonomic classifications)

Related Terms (Scientific Context)

• Agnatha: The superclass of jawless vertebrates, which includes cephalaspids.
• Vertebrate: An animal with a backbone or spinal column.
• Paleontology: The branch of science concerned with fossil animals and plants.

Noun

1. extinct group of armored fish-like vertebrates; taxonomy is not clear