View source for Oegopsida

{{Short description|Order of squids}}
{{Automatic taxobox
| fossil_range = {{fossil range|Cenomanian|recent|[[Cenomanian]] – recent<ref name="Ikegami2025">{{Cite journal|last1=Ikegami |first1=Shin |last2=Takeda |first2=Yusuke |last3=Mutterlose |first3=Jörg |last4=Iba |first4=Yasuhiro |title=Origin and radiation of squids revealed by digital fossil-mining |year=2025 |journal=Science |volume=388 |issue=6754 |pages=1406–1409 |doi=10.1126/science.adu6248 |pmid=40570114 }}</ref>}}
| image = Moroteuthis ingens.jpg
| image_caption = ''[[Moroteuthis ingens]]''
| taxon = Oegopsida
| authority = [[Alcide d'Orbigny|Orbigny]], 1845<ref name = WoRMS>{{cite web | url = http://www.marinespecies.org/aphia.php?p=taxdetails&id=11730 | title = Oegopsida | access-date = 22 February 2018 | publisher = Flanders Marine Institute | author = Philippe Bouchet | year = 2018 | work = World Register of Marine Species}}</ref>
| subdivision_ranks = Families
| subdivision = See text
| synonyms = *Decabranchia
*Decapoda <small>Leach, 1817</small>
}}

'''Oegopsida''' is one of the four [[Order (biology)|orders]] of [[squid]] in the [[superorder]] [[Decapodiformes]], in the [[Class (biology)|class]] [[Cephalopod]]a. Together with the [[Myopsida|Myopsina]], it was formerly considered to be a suborder of the order Teuthida, in which case it was known as '''Oegopsina'''. This reclassification is due to Oegopsina and Myopsina not being demonstrated to form a clade.<ref name = Timetree>{{cite book | editor1 = S. Blair Hedges | editor2 = Sudhir Kumar | year = 2009 | title = The Timetree of Life | chapter = Cephalopod mollusks Cephalopoda | pages = 2–18 | publisher = OUP Oxford  | author1 = Jan M. Strugnell | author2 = Annie Lindgren | author3-link = Louise Allcock | author3 = Louise M. Allcock}}</ref>

The Oegopsida are an often pelagic squid, with some nerito-oceanic species associated with sea mounts.<ref>{{Cite book|url=http://www.fao.org/docrep/014/i1920e/i1920e04.pdf|title=Cephalopods of the world: an annotated and illustrated catalogue of cephalopod species known to date|last=P.|first=Roper, Clyde F. E., 1937- Jereb|date=2010|publisher=Food and Agriculture Organization of the United Nations|isbn=978-92-5-105383-6|oclc=880299294}}</ref> They consist of 24 [[family (biology)|families]] and 69 [[genus|genera]]. They have these characters in common: the head is without tentacle pockets, eyes lack a corneal covering, arms and tentacle clubs may have hooks, the buccal supports are without suckers, and oviducts in females are paired.

Two families, the [[Bathyteuthidae]] and [[Chtenopterygidae]], which have features characteristic of the [[Myopsida]] while retaining others common to the Oegopsina, were formerly placed in the family, but are now placed in their own order [[Bathyteuthida]].<ref name=":0" />

The Oegopsida differ from the coastal Myopsida, characterised by the genus ''[[Loligo]]'', which have corneal coverings over the eyes and tentacle pockets, but lack hooks, have no suckers on the buccal supports, and a single oviduct.

Oegopsid squid are the only decapods that lack a pocket for the tentacles. Otherwise, they share different characters with different decapod groups. Like the Bathyteuthida and Myopsida, the Oegopsida have a brachial canal, which is absent in other forms. As with the [[Spirulidae]] and [[Idiosepiidae]], the Oegopsida lack suckers on the buccal supports, and like the Bathyteuthida, Idiosepiidae, and Spirulidae, they have no circular muscle on the suckers.

== Evolution ==
The earliest fossils of Oegopsida are [[Cephalopod beak|jaw]] fragments from the Late Cretaceous. Prior to 2025, the earliest of these were known from the [[Santonian]] or early [[Campanian]] of the [[Yezo Group]] in [[Hokkaido]], [[Japan]]. These jaw fragments are extremely large, suggesting that oegopsids could already evolve very large body sizes early on. One of these fossils was described as the genus ''[[Yezoteuthis]]'', which has been estimated to rival the modern [[giant squid]] in size. Another jaw fragment described in 2023 was found to be twice as long as a giant squid's jaws.<ref name="Tanabe2006">{{Cite journal |last1=Tanabe |first1=Kazushige |last2=Hikida |first2=Yoshinori |last3=Iba |first3=Yasuhiro |date=January 2006 |title=Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/two-coleoid-jaws-from-the-upper-cretaceous-of-hokkaido-japan/E9AB99CDD77DBEF1736FF42771EB8E6B |journal=Journal of Paleontology |language=en |volume=80 |issue=1 |pages=138–145 |doi=10.1666/0022-3360(2006)080[0138:TCJFTU]2.0.CO;2 |issn=0022-3360|url-access=subscription }}</ref><ref>{{Cite journal |last1=Tanabe |first1=Kazushige |last2=Misaki |first2=Akihiro |date=2023-11-01 |title=Upper Cretaceous record of non-belemnitid coleoid jaws from Hokkaido, Japan, and its evolutionary implications |journal=Cretaceous Research |volume=151 |article-number=105624 |doi=10.1016/j.cretres.2023.105624 |issn=0195-6671|doi-access=free |bibcode=2023CrRes.15105624T }}</ref>

In 2025, numerous other fossil beaks, comprising many newly-described genera and families, were identified from the Yezo Group, dating back to at least the earliest [[Cenomanian]]. This confirms that oegopsids were already a dominant component of Cretaceous seas and had diverged from the myopsids by this time. However, ''Yezoteuthis'', the earliest described fossil oegopsid, was found to be a squid of uncertain affinities.<ref name="Ikegami2025" />

== Taxonomy ==
The following taxonomic classification was found by Fernández-Álvarez ''et al''., 2021:<ref name=":0">{{Cite journal |last1=Fernández-Álvarez |first1=Fernando Ángel |last2=Taite |first2=Morag |last3=Vecchione |first3=Michael |last4=Villanueva |first4=Roger |last5=Louise |first5=Allcock |title=A phylogenomic look into the systematics of oceanic squids |url=https://academic.oup.com/zoolinnean/article/194/4/1212/6377132 |access-date=2023-04-08 |website=academic.oup.com |doi=10.1093/zoolinnean/zlab069|doi-access=free |hdl=10261/267184 |hdl-access=free }}</ref>

*Order Oegopsida
**Superfamily [[Architeuthoidea]]
***Family [[Architeuthidae]]
***Family [[Neoteuthidae]]
**Superfamily [[Cranchioidea]]
***Family [[glass squid|Cranchiidae]]
***Family [[Ommastrephidae]]
***Family [[Thysanoteuthidae]]
**Superfamily [[Chiroteuthoidea]]
***Family [[Batoteuthidae]]
***Family [[Chiroteuthidae]]
***Family [[Joubiniteuthidae]]
***Family [[Magnapinnidae]]
***Family [[Mastigoteuthidae]]
***Family [[Promachoteuthidae]]
**Superfamily [[Cycloteuthoidea]]
***Family [[Brachioteuthidae]]
***Family [[Cycloteuthidae]]
**Superfamily [[Enoploteuthoidea]]
***Family [[Ancistrocheiridae]]
***Family [[Enoploteuthidae]]
***Family [[Lampadioteuthis|Lampadioteuthidae]]
***Family [[Lycoteuthidae]]
***Family [[Pyroteuthidae]]
**Superfamily [[Pholidoteuthoidea]]
***Family [[Pholidoteuthidae]]
**Superfamily [[Octopoteuthoidea]]
***Family [[Lepidoteuthidae]]
***Family [[Octopoteuthidae]]
**''incertae sedis''
***Family [[Gonatidae]]
***Family [[Histioteuthidae]]
***Family [[Onychoteuthidae]]
***Family [[Psychroteuthidae]]

=== Fossil families ===

* Genus ?†''[[Yezoteuthis]]<ref name="Tanabe2006" />''
* Family †[[Haboroteuthidae]]<ref name="Ikegami20252" />
* Family †[[Pachypteroteuthidae]]<ref name="Ikegami20252" />
* Family †[[Scuthoteuthidae]]<ref name="Ikegami20252" />
* Family †[[Paleothysanoteuthidae]]<ref name="Ikegami20252" />

===Phylogeny===
The following phylogeny was found by Fernández-Álvarez ''et al''., 2021:<ref name=":0" />
{{clade
   |label1=Oegopsida
   |1= {{clade
       |label1=[[Cranchioidea]]
       |1={{clade 
           |1=[[Cranchiidae]]
           |2={{clade
               |1=[[Ommastrephidae]]
               |2=[[Thysanoteuthidae]]
               }}
           }}
       |2={{clade
           |1=[[Gonatidae]]
           |2={{clade
              |1={{clade
                 |1=[[Histioteuthidae]]
                 |2=[[Onychoteuthidae]]
              }}
              |2={{clade
                   |label1=[[Architeuthoidea]]
                   |1={{clade
                      |1=[[Architeuthidae]]
                      |2=[[Neoteuthidae]]
                  }}
                 |2={{clade
                     |label1=[[Cycloteuthoidea]]
                     |1={{clade 
                         |1=[[Cycloteuthidae]]
                         |2=[[Brachioteuthidae]]
                        }}
                    |2={{clade
                        |1={{clade
                            |label1=[[Enoploteuthoidea]]
                            |1={{clade
                                |1={{clade
                                   |1=[[Enoploteuthidae]]
                                   |2=[[Ancistrocheiridae]]
                                }}
                                |2={{clade
                                   |1=[[Lampadioteuthidae]]
                                   |2={{clade
                                       |1=[[Lycoteuthidae]]
                                       |2=[[Pyroteuthidae]]
                                    }}
                                }}
                            }}
                            |2={{clade
                                |label1=[[Octopoteuthoidea]] 
                                |1={{clade
                                     |1=[[Octopoteuthidae]]
                                     |2=[[Lepidoteuthidae]]
                                }}
                                |2={{clade
                                   |label2=[[Pholidoteuthoidea]]
                                   |2=[[Pholidoteuthidae]]
                                   |label1=[[Chiroteuthoidea]]
                                   |1={{clade
                                       |1=[[Chiroteuthidae]]
                                       |2={{clade
                                         |1=[[Mastigoteuthidae]]
                                         |2={{clade
                                            |1=[[Magnapinnidae]]
                                            |2=[[Joubiniteuthidae]]
                                         }}
                                       }} 
                                    }}
                               }}
                           }}
                      }}
                    }}
                }} 
             }}
             }}
          }}
      }}
}}

==References==
{{Reflist|25em}}

==External links==
{{Wikispecies|Oegopsida}}
{{Wikibooks|Dichotomous Key|Oegopsina}}
* {{CephBase Suborder|Oegopsina}}

{{Taxonbar|from=Q639672}}

[[Category:Oegopsida| ]]
[[Category:Squid]]
[[Category:Decapodiformes]]

{{Squid-stub}}