Editing Lancelet (section)

== History ==

=== Taxonomy ===

The first representative organism of the group to be described was ''[[Branchiostoma lanceolatum]]''. It was described by [[Peter Simon Pallas]] in 1774 as [[mollusc]]an slugs in the genus ''[[Limax]]''.<ref>{{cite book | last1 = Pallas | first1 = Peter Simon | year = 1774 | publisher = Gottlieb August Lange | location = Berlin | pages = 41 | title = Spicilegia Zoologica. Fasciculus decimus}}</ref> It was not until 1834 that Gabriel Costa brought the phylogenetic position of the group closer to the agnathan vertebrates ([[hagfish]] and [[lampreys]]), including it in the new genus ''[[Branchiostoma]]'' (from the Greek, branchio = "gills", stoma = "mouth").<ref>{{cite book | last1 = Costa | first1 = Oronzio-Gabriele | year = 1834 | url = https://books.google.com/books?id=zfNhAAAAcAAJ | publisher = Tipografia di Azzolino e Comp. | location = Naples | pages = 90 | title = Cenni zoologici ossia descrizione sommaria delle specie nuove di animali discoperti in diverse contrade del regno nell' anno 1834}}</ref><ref name="Garcia-Fernàndez">{{Cite journal | first1 = Jordi | last1 = Garcia-Fernàndez  | first2 = Èlia | last2 = Benito-Gutierrez | title = It's a long way from amphioxus: descendants of the earliest chordate | journal = BioEssays | volume = 31 | issue = 6 | pages = 665–675| date = June 2008 | doi = 10.1002/bies.200800110 | pmid=19408244| s2cid = 9292134 }}</ref> In 1836, Yarrell renamed the genus as ''Amphioxus'' (from the Greek: "pointed on both sides"),<ref>{{cite book | last1 = Yarrell | first1 = William | year = 1836 | url = https://www.biodiversitylibrary.org/item/75546 | publisher = John van Voorst | location = London | pages = 472 | title = A History of British Fishes. Vol. II| volume = 2 }}</ref> now considered an obsolete [[Synonym (taxonomy)|synonym]] of the genus ''Branchiostoma''. Today, the term "amphioxus" is still used as a [[common name]] for the Amphioxiformes, along with "lancelet", especially in the English language.

All living lancelets are all placed in the family Branchiostomatidae, class Leptocardii, and subphylum Cephalochordata.<ref>{{cite WoRMS |author=WoRMS |year=2024 |title=Branchiostomatidae Bonaparte, 1846 |id=196078 |access-date=11 February 2024}}</ref> The family was first named by [[Charles Lucien Bonaparte]] in 1846, though he used the incorrect spelling "Branchiostomidae".<ref name="Bonaparte1846">{{cite book | last1 = Bonaparte | first1 = Charles-Lucien | year = 1846 | url = https://www.biodiversitylibrary.org/item/121384 | publisher = Stamperia e Cartiere del Fibreno | location = Naples | pages = 97 | title = Catalogo metodico dei pesci europei}}</ref> One year previously, [[Johannes Peter Müller|Johannes Müller]] had introduced the name Leptocardii as a subclass.<ref name="Müller1845">{{cite journal | last1 = Müller | first1 = Johannes | year = 1845 | url = https://www.zobodat.at/publikation_articles.php?id=227421 | pages = 91–141 | title = Ueber den Bau und die Grenzen der Ganoiden, und über das natürliche System der Fische | journal = Archiv für Naturgeschichte | volume = 11 | issue = 1}}</ref>
Finally, the subphylum name Cephalochordata is attributed to [[Ernst Haeckel]] (1866).<ref name="Nielsen2012" /> At the taxonomic rank of order, lancelets are sometimes placed in the order Amphioxi Bonaparte, 1846,<ref>{{cite journal | last1 = Boschung | first1 = Herbert T. | last2 = Shaw | first2 = Richard F. | year = 1988 | pages = 229–240 | title = Occurrence of planktonic lancelets from Louisiana's continental shelf, with a review of pelagic ''Branchiostoma'' (order Amphioxi) | journal = Bulletin of Marine Science | volume = 43 | issue = 2}}</ref> Amphioxiformes Berg, 1937,<ref name="Fowler1965">{{cite journal | last1 = Fowler | first1 = H.W. | year = 1965 | title = A catalog of World Fishes. Part II | journal = Quarterly Journal of the Taiwan Museum | volume = 18 | pages = 137–202 }}<!-- contains citation attributing the name to Berg, 1937 --></ref><ref name="Poss1996">{{cite journal | last1 = Poss | first1 = Stuart G. | last2 = Boschung | first2 = Herbert T. | year = 1996 | pages = S13–S66 | title = Lancelets (Cephalochordata: Branchiostomatidae): how many species are valid? | journal = Israel Journal of Zoology | volume = 42 | issue = Suppl. 1}}<!-- example of a paper using the name Amphioxiformes (p. S-38) --></ref> or Branchiostomiformes Fowler, 1947.<ref name="Fowler1947">{{cite journal | last1 = Fowler | first1 = Henry W. | year = 1947 | url = https://books.google.com/books?id=tx_0VVLTUeQC&pg=PA3 | pages = 1–16 | title = New taxonomic names of fish-like vertebrates | journal = Notulae Naturae | volume = 187| isbn = 978-1-60483-187-0 }}</ref> Another name sometimes used for high-ranked taxa for the lancelets is Acrania Haeckel, 1866.<ref name="Poss1996" /><!-- example usage -->

=== Anatomy ===
Observations of amphioxus anatomy began in the middle of the 19th century. First, the adult then the embryonic anatomy were described.<ref name=":1">{{Cite book|title=Entwickelungsgeschichte des Amphioxus lanceolatus|last=Kowalevsky AO.|publisher=Mém Acad Sci St Petersburg.|year=1867}}</ref>

Alexander Kowalevsky first described the key anatomical features of the adult amphioxus (hollow dorsal nerve tube, endostyle, segmented body, postanal tail).<ref name=":1" /> De Quatrefages first completely described the nervous system of amphioxus.<ref>{{Cite book|title=Annales des sciences naturelles|last=de Quatrefages|first=M. A.|publisher=Libraires-editeurs|year=1845}}</ref> Other important contributions to amphioxus adult anatomy were given by Heinrich Rathke <ref>{{Cite book|title=Bemerkungen uber den Bau des Amphioxus lanceolatus eines Fisches aus der Ordnung der Cyclostomen|url=https://archive.org/details/b22392531|last=H. Rathke|publisher=Gebrüder Bornträger|year=1841}}</ref> and John Goodsir.<ref>{{Cite book|title=Proc. R. Soc. Edinb|last=J. Goodsir|year=1844}}</ref>

Kowalevsky also released the first complete description of amphioxus embryos,<ref name=":1" /> while Schultze and Leuckart were the first to describe the larvae.<ref>{{Cite book|title=Z. Wiss. Zool.|last=M. Schultze|year=1851}}</ref> Other important contributions to amphioxus embryonic anatomy were given by Hatschek, Conklin<ref>{{Cite journal|title=The Amphioxus and Its Development|journal=Nature|volume=48|issue=1252|last=B. Hatschek|year=1893|pages=613|bibcode=1893Natur..48..613E|doi=10.1038/048613a0|hdl=2027/hvd.hn25lj|s2cid=4016509|url=https://archive.org/details/amphioxusitsdeve00hats|doi-access=free}}</ref> and later by Tung (experimental embryology).<ref>{{Cite book|title=Dev. Growth. Differ|last=S. Yan|publisher=1999}}</ref>