Definition

1. Noun:
   • A taxonomic subphylum within the phylum Chordata: This subphylum comprises small, fish-like marine chordates known for their elongated, lance-shaped bodies. They are characterized by having a notochord that extends the full length of the body into the head region, which is a defining feature of the group.

Usage Examples

• Noun:
  • The subphylum Cephalochordata includes organisms like the lancelet, Branchiostoma.
  • In evolutionary biology, the subphylum Cephalochordata is studied for insights into early chordate development.

Advanced Usage

• In scientific classification: The term is used in formal taxonomic hierarchy (Kingdom: Animalia, Phylum: Chordata, Subphylum: Cephalochordata).
  • The specimen was classified under the subphylum Cephalochordata based on its anatomical features.

Variants and Related Words

• Cephalochordate (n): A member of the subphylum Cephalochordata; a lancelet.
  • The cephalochordate filter-feeds on microscopic organisms.
• Lancelet (n): The common name for any cephalochordate.
  • Lancelets are often found buried in sandy seabeds.

Synonyms

• Lancelets: The common name for the organisms within this subphylum.
• Acrania: An older, less common taxonomic name sometimes used synonymously for this group, referring to the lack of a true skull.

Noun

1. lancelets