Dictionary > Cephalochordate

Cephalochordate

Definition
noun, plural: cephalochordates
Any of the small, elongated, segmented, fish-like chordates that belong to the subphylum Cephalochordata, such as lancelets
Supplement
Chordates are primarily characterized by having a notochord, dorsal hollow nerve cord, muscular post anal tail, and pharyngeal slits for at least some period of the life cycle of an animal. The phylum Chordata has three subphyla: Vertebrata (vertebrates), Tunicata (tunicates), and Cephalochordata (cephalochordates).
As a chordate, the cephalochordates possess a notochord. However, their notochord (as well as the dorsal nerve cord, endostyle, pharynx, and post-anal tail) persists till adulthood. Their notochord extends from head to tail. The cephalochordates are small and lack any hard parts. The lancelets (of about 32 species) serve as the modern representatives of this subphylum.
Other species belonging to the subphylum are already extinct. For instance, Pikaia gracilens species were recovered from the Burgess Shale (i.e. a fossil-bearing deposit located in the Canadian Rockies of British Columbia, Canada). They look similar to the lancelet and probably swam like the eels. Cathaymyrus species were found from the Chengjiang County, Yuman Province in China. They possessed an elongated, segmented body but without distinctive head.
Word origin: Ancient Greek kephalḗ (“head”) + chordata
Scientific classification:

  • Kingdom: Animalia
  • Phylum: Chordata
  • Subphylum: Cephalochordata (Haeckel, 1866)

See also:


You will also like...

Sensory systems
Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal ..

Physiological Homeostasis
Physiological Homeostasis

Homeostasis is essential to maintain conditions within the tolerable limits. Otherwise, the body will fail to function p..

Endemic Flora of New Zealand
New Zealand’s Unique Flora

If New Zealand has lots of unique animals, it's also got a whole lot of unique plants. Find out more about some of them,..

Growth and Plant Hormones
Growth and Plant Hormones

Plants, like animals, produce hormones to regulate plant activities, including growth. They need these hormones to respo..

Early Mammals on Earth
Early Mammals on Earth

The Earth's ecosphere was rapidly changing and throwing up a wide range of ecological niches that new adaptive organisms..

Protein (illustration)
Protein Variety

The sequence of amino acids determines the type of protein. Protein is synthesized according to the sequence of nucleoti..

Related Articles...

No related articles found

See all Related Topics