Urochord (Noun)
Meaning 1
A notochord of a larval tunicate typically confined to the caudal region.
Classification
Nouns denoting animals.
Examples
- The tunicate larva possesses an exceptionally long urochord compared to its smaller trunk region.
- During metamorphosis of a larval tunicate, the urochord disappears or is significantly reduced in size.
- A larval tunicate utilizes its urochord as part of a flexible and mobile structure, in its caudal region, before undergoing transformation to an adult.
- The muscle bands located within the non-urochord tail, have little developmental interaction with tunicate muscles found near the urochord region.
- As a larval urochordate matures and reaches its late stage of development, the urochord does not extend much further than its caudal region.
Meaning 2
Primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva.
Classification
Nouns denoting animals.
Examples
- The simplest chordates are the urochordates or tunicates, with the distinctive larval urochord vanishing in adulthood.
- A possible explanation could be an advanced ancestor that evolved back into the primitive marine animal again with a distinct larval urochord.
- The tunicates display a unique larval form displaying a prominent urochord resembling microscopic sausages in photographs.
- Unlike their advanced descendants, the primitive larvae have several precursors including a notable urochord eventually being absorbed with time.
- These organisms evolved to produce a tunic covering in the adult and contain striking larval characteristics including a short-lived urochord.