Definition of siphuncle in English:

siphuncle

Line breaks: siph|uncle
Pronunciation: /ˈsʌɪfʌŋk(ə)l
 
/

noun

Zoology
(In shelled cephalopods such as nautiloids and ammonoids) a calcareous tube containing living tissue running through all the shell chambers, serving to pump fluid out of vacant chambers in order to adjust buoyancy.
More example sentences
  • The dorsal siphuncles of the Clymeniida tend to be larger than the ventral siphuncles of other ammonoid clades.
  • Outwardly indistinguishable from other ammonoids, clymeniids are distinguished internally by their dorsal siphuncle, contrasted to a ventral siphuncle in almost all other ammonoids.
  • Given that the shell that covers the siphuncle is its only permeable surface, the interchange of fluids can take place only through this structure.

Origin

mid 18th century: from Latin siphunculus 'small tube'.

More definitions of siphuncle

Definition of siphuncle in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day grammarian
Pronunciation: grəˈmɛːrɪən
noun
a person who studies and writes about grammar