amphioxus

noun

am·​phi·​ox·​us ˌam(p)-fē-ˈäk-səs 

plural amphioxi ˌam(p)-fē-ˈäk-ˌsī  or amphioxuses

: any of a genus (Branchiostoma) of lancelets

broadly : lancelet

Examples of amphioxus in a Sentence

Recent Examples on the Web

So, the presence of cartilage suggests that, even at this early stage of their evolution, vertebrates probably had a distinct nerve cord that produced a neural crest—something that our close relatives like the amphioxus doesn't have. —John Timmer, Ars Technica, 7 July 2022

If that interpretation is correct, then that would mean yunnanozoans look a lot like an amphioxus, but have a feature that's otherwise found only in modern vertebrates. —John Timmer, Ars Technica, 7 July 2022

Word History

Etymology

borrowed from New Latin, genus name, from Greek amphi- amphi- + oxýs "sharp, keen" — more at oxygen

Note: The genus name Amphioxus was introduced by the English naturalist and bookseller William Yarrell (1784-1856) in A History of British Fishes, vol. 2 (London, 1836), pp. 468-72. The name alludes to the shape of the animal: "both ends pointed," as noted under "generic characters." Yarrell was unaware that the Italian zoologist Gabriele Costa had named the same genus Branchiostoma two years earlier (in Cenni zoologici, ossia descrizione sommaria delle specie nuove di animali, Naples, 1834, p. 49); by rules of taxonomy, the name Branchiostoma hence has priority over Amphioxus.

First Known Use

1837, in the meaning defined above

Kids Definition

amphioxus

noun

am·​phi·​ox·​us ˌam(p)-fē-ˈäk-səs 

plural amphioxi

-ˈäk-ˌsī

or amphioxuses

: lancelet

Medical Definition

amphioxus

1 of 2 noun

am·​phi·​ox·​us ˌam(p)-fē-ˈäk-səs 

plural amphioxi -ˌsī  -ˌsē  or amphioxuses

: a lancelet of the genus Branchiostoma

broadly : lancelet

Amphioxus

2 of 2 noun

taxonomic synonym of branchiostoma