Editing Barnacle (section)

== Evolution ==

=== Fossil record ===

The oldest definitive fossil barnacle is ''[[Praelepas]]'' from the mid-[[Carboniferous]], around 330-320 million years ago.<ref name="Chan Dreyer Gale 2021"/> Older claimed barnacles such as ''[[Priscansermarinus]]'' from the [[Middle Cambrian]], some {{Ma|510|500}},<ref name=Foster1987>{{cite book |last1=Foster |first1=B. A. |last2=Buckeridge |first2=J. S. |year=1987 |title=Barnacle palaeontology |pages=41–63}} In [[#refSouthward|A. J. Southward (ed.), 1987]].</ref> do not show clear barnacle morphological traits, though ''[[Rhamphoverritor]]'' from the [[Silurian]] [[Coalbrookdale Formation]] of England may represent a [[Crown group|stem-group]] barnacle. Barnacles first [[Evolutionary radiation|radiated]] and became diverse during the Late [[Cretaceous]]. Barnacles underwent a second, much larger radiation beginning during the [[Neogene]] and still continuing.<ref name="Chan Dreyer Gale 2021"/>

<gallery class=center mode=nolines widths=275px heights=150px>
File:Megabalanus on breccia (cropped).JPG|[[Miocene]] ([[Messinian]]) ''[[Megabalanus]]'', smothered by sand and fossilised
File:Chesaconcavus top view.jpg|''Chesaconcavus'', a Miocene barnacle from Maryland
File:Chesaconcavus base detail.jpg|Underside of large ''Chesaconcavus'' showing internal plates in bioimmured smaller barnacles
</gallery>

=== Phylogeny ===

The following [[cladogram]], not fully resolved, shows the [[Phylogenetics|phylogenetic]] relationships of the Cirripedia within [[Thecostraca]] as of 2021.<ref name="Chan Dreyer Gale 2021"/><!--<ref name="Perez-Losada Hoeg Crandall 2012 pp. 430–442">{{cite journal |last=Perez-Losada |first=M. |last2=Hoeg |first2=J. T. |last3=Crandall |first3=K. A. |title=Deep Phylogeny and Character Evolution in Thecostraca (Crustacea: Maxillopoda) |journal=Integrative and Comparative Biology |volume=52 |issue=3 |date=2012-09-01 |doi=10.1093/icb/ics051 |pages=430–442}}</ref>-->

{{clade
|label1=[[Thecostraca]]
|1={{clade
   |1=[[Facetotecta]]
   |2={{clade
      |label1=[[Ascothoracida]]
      |1={{clade
         |1=[[Laurida]]
         |2=[[Dendrogastrida]]
         }}
      |label2='''Cirripedia'''
      |2={{clade
         |1={{clade
            |label1=[[Acrothoracica]]
            |sublabel1=''burrowing''
            |1={{clade
               |1=[[Cryptophialida]]
               |2=[[Lithoglyptida]]
               }}
            }}
         |2={{clade
            |label1=[[Thoracica]]
            |sublabel1="goose", etc
            |1={{clade
               |1=[[Iblomorpha]]
               |label2=[[Thoracicalcarea]]
               |2={{clade
                  |1={{clade
                     |1=[[Pollicipedomorpha]]
                     |2={{clade
                        |1=[[Calanticomorpha]]
                        |2=[[Scalpellomorpha]]
                        |3={{clade
                           |label1=[[Sessilia]]
                           |sublabel1=''unstalked''
                           |1={{clade
                              |1=[[Verrucomorpha]]
                              |2=[[Balanomorpha]]
                              }}
                           }}
                        }}
                     }}
                  }}
               }}
            |sublabel2=''parasitic''
            |2=[[Rhizocephala]]
            }}
         }}
      }}
   }}
}}

=== Taxonomy ===

{{further|List of Cirripedia genera}}

Over 2,100 species of Cirripedia have been described.<ref name="Chan Dreyer Gale 2021"/> Some authorities regard the Cirripedia as a full [[class (biology)|class]] or [[Subclass (biology)|subclass]]. In 2001, Martin and Davis placed Cirripedia as an infraclass of [[Thecostraca]], and divided it into six orders:<ref>{{cite book |last1=Martin |first1=Joel W. |last2=Davis |first2=George E. |title=An Updated Classification of the Recent Crustacea |year=2001 |citeseerx=10.1.1.79.1863 |pages=21–23 |url=https://www.vliz.be/imisdocs/publications/ocrd/121258.pdf}}</ref>

* Infraclass '''Cirripedia''' <small>[[Hermann Burmeister|Burmeister]], 1834</small>
** Superorder [[Acrothoracica]] <small>Gruvel, 1905</small>
*** Order Pygophora <small>Berndt, 1907</small>
*** Order Apygophora <small>Berndt, 1907</small>
** Superorder [[Rhizocephala]] <small>Müller, 1862</small>
*** Order Kentrogonida <small>Delage, 1884</small>
*** Order Akentrogonida <small>Häfele, 1911</small>
** Superorder [[Thoracica]] <small>[[Charles Darwin|Darwin]], 1854</small>
*** Order Pedunculata <small>[[Jean-Baptiste Lamarck|Lamarck]], 1818</small>
*** Order [[Sessilia]] <small>Lamarck, 1818</small>

In 2021, Chan et al. elevated Cirripedia to a subclass of the [[Thecostraca]], and the superorders Acrothoracica, Rhizocephala, and Thoracica to infraclass. The updated classification with 11 orders has been accepted in the [[World Register of Marine Species]].<ref name="Chan Dreyer Gale 2021">{{cite journal |title=The evolutionary diversity of barnacles, with an updated classification of fossil and living forms |date=2021 |last1=Chan |first1=Benny K. K. |last2=Dreyer |first2=Niklas |last3=Gale |first3=Andy S. |last4=Glenner |first4=Henrik |last5=Ewers-Saucedo |first5=Christine |last6=Pérez-Losada |first6=Marcos |last7=Kolbasov |first7=Gregory A. |last8=Crandall |first8=Keith A. |last9=Høeg |first9=Jens T. |display-authors=6 |journal=Zoological Journal of the Linnean Society |volume=193 |issue=3 |pages=789–846 |doi=10.1093/zoolinnean/zlaa160|doi-access=free |hdl=11250/2990967 |hdl-access=free}}</ref><ref name=worms>{{cite web |url=http://marinespecies.org/aphia.php?p=taxdetails&id=1082 |title=Cirripedia |website=[[World Register of Marine Species]] |publisher=Flanders Marine Institute |access-date=22 August 2021}}</ref>

* Subclass '''Cirripedia''' <small>[[Hermann Burmeister|Burmeister]], 1834</small>
** Infraclass [[Acrothoracica]] <small>Gruvel, 1905</small>
*** Order [[Cryptophialida]] <small>Kolbasov, Newman & Hoeg, 2009</small>
*** Order [[Lithoglyptida]] <small>Kolbasov, Newman & Hoeg, 2009</small>
** Infraclass [[Rhizocephala]] <small>Müller, 1862</small>
** Infraclass [[Thoracica]] <small>Darwin, 1854</small>
*** Superorder [[Phosphatothoracica]] <small>Gale, 2019</small>
**** Order [[Iblomorpha]] <small>Buckeridge & Newman, 2006</small>
**** Order † [[Eolepadomorpha]] <small>Chan et al., 2021</small>
*** Superorder [[Thoracicalcarea]] <small>Gale, 2015</small>
**** Order [[Calanticomorpha]] <small>Chan et al., 2021</small>
**** Order [[Pollicipedomorpha]] <small>Chan et al., 2021</small>
**** Order [[Scalpellomorpha]] <small>Buckeridge & Newman, 2006</small>
**** Order † [[Archaeolepadomorpha]] <small>Chan et al., 2021</small>
**** Order † [[Brachylepadomorpha]] <small>Withers, 1923</small>
**** (Unranked) [[Sessilia]]
***** Order [[Balanomorpha]] <small>Pilsbry, 1916</small>
***** Order [[Verrucomorpha]] <small>Pilsbry, 1916</small>