Editing Squid (section)

===Evolution===
[[Crown group|Crown]] coleoids (the common ancestor of octopuses and squid) diverged in the late [[Paleozoic]] ([[Mississippian (geology)|Mississippian]]), according to fossils of ''[[Syllipsimopodi]]'', an early relative of vampire squids and octopuses.<ref>{{Cite journal |last1=Whalen |first1=Christopher D. |last2=Landman |first2=Neil H. |date=2022-03-08 |title=Fossil coleoid cephalopod from the Mississippian Bear Gulch Lagerstätte sheds light on early vampyropod evolution |journal=Nature Communications |language=en |volume=13 |issue=1 |page=1107 |doi=10.1038/s41467-022-28333-5 |pmid=35260548 |pmc=8904582 |bibcode=2022NatCo..13.1107W |issn=2041-1723}}</ref> True squid diverged during the Jurassic, but many squid families appeared in or after the [[Cretaceous]].<ref name="Tanner Fuchs Winkelmann Gilbert p=20162818">{{cite journal | last1=Tanner | first1=Alastair R. | last2=Fuchs | first2=Dirk | last3=Winkelmann | first3=Inger E. | last4=Gilbert | first4=M. Thomas P. | last5=Pankey | first5=M. Sabrina | last6=Ribeiro | first6=Ângela M. | last7=Kocot | first7=Kevin M. | last8=Halanych | first8=Kenneth M. | last9=Oakley | first9=Todd H. | last10=da Fonseca | first10=Rute R. | last11=Pisani | first11=Davide | last12=Vinther | first12=Jakob | title=Molecular clocks indicate turnover and diversification of modern coleoid cephalopods during the Mesozoic Marine Revolution | journal=Proceedings of the Royal Society B: Biological Sciences | volume=284 | issue=1850 | date=March 2017 | doi=10.1098/rspb.2016.2818 | pmid=28250188 | pmc=5360930 | page=20162818}}</ref> Both the coleoids and the teleost fish were involved in much adaptive radiation at this time, and the two modern groups resemble each other in size, ecology, habitat, morphology and behaviour, however some fish moved into fresh water while the coleoids remained in marine environments.<ref name=Ruppert/>

The ancestral coleoid was probably nautiloid-like with a strait septate shell that became immersed in the mantle and was used for buoyancy control. Four lines diverged from this, Spirulida (with one living member), the [[cuttlefish]]es, the squids and the [[octopus]]es. Squid have differentiated from the ancestral [[mollusc]] such that the body plan has been condensed antero-posteriorly and extended dorso-ventrally. What may have been the [[Foot (mollusc)|foot]] of the ancestor is modified into a complex set of appendages around the mouth. The sense organs are highly developed and include advanced eyes similar to those of [[vertebrate]]s.<ref name=Ruppert>{{cite book |title=Invertebrate Zoology |edition=7th |last1=Ruppert |first1=Edward E. |last2=Fox |first2=Richard S. |last3=Barnes |first3=Robert D. |year=2004 |publisher=[[CEngage Learning]] |isbn=978-81-315-0104-7 |pages=343–367 |url=https://books.google.com/books?id=A3opAQAAMAAJ}}</ref>

The ancestral shell has been lost, with only an internal [[gladius (cephalopod)|gladius]], or pen, remaining. The pen, made of a chitin-like material,<ref name=Ruppert/><ref name="ifuku">{{cite journal |last=Ifuku |first=S. |title=Chitin and chitosan nanofibers: preparation and chemical modifications |pmid=25393598 |pmc=6271128 |journal=Molecules |year=2014 |volume=19 |issue=11 |pages=18367–80 |doi=10.3390/molecules191118367 |doi-access=free }}</ref> is a feather-shaped internal structure that supports the squid's mantle and serves as a site for muscle attachment. The [[cuttlebone]] or sepion of the Sepiidae is [[calcareous]] and appears to have evolved afresh in the [[Tertiary]].<ref name="Bonnaud 2006">{{cite journal | last1=Bonnaud | first1=Laure | last2=Lu | first2=C. C. | last3=Boucher-Rodoni | first3=Renata | title=Morphological character evolution and molecular trees in sepiids (Mollusca: Cephalopoda): is the cuttlebone a robust phylogenetic marker? | journal=Biological Journal of the Linnean Society | volume=89 | issue=1 | date=2006 | doi=10.1111/j.1095-8312.2006.00664.x | pages=139–150| doi-access=free }}</ref>

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File:Rhomboteuthis lehmani (cropped).jpg|Fossil ''[[Rhomboteuthis]]'' from the [[Callovian|Lower Callovian]] ({{circa| 164 [[Million years ago|Mya]]}}, middle Jurassic) of [[La Voulte-sur-Rhône (lagerstätte)|La Voulte-sur-Rhône]], France
File:Plesioteuthis prisca 01.jpg|Fossil ''[[Plesioteuthis]]'' from the [[Tithonian]] ({{circa|150 Mya}}, upper Jurassic), [[Solnhofen limestone|Solnhofen]], Germany
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