View source for Physics:Flatfish

{{short description|Order of fishes}}
{{Automatic taxobox
| name = Flatfish
| fossil_range = {{Fossil range|Paleocene|Recent|ref=<ref name=EoF/>}}
| image = Flounder camo md.jpg
| image_caption = A [[Biology:Camouflage|camouflage]]d flatfish
| taxon = Pleuronectiformes
| subdivision_ranks = Families
| subdivision_ref = <ref name="Nelson-2006">{{Cite book
| subdivision =
'''Suborder Psettodoidei'''
: [[Biology:Psettodidae|Psettodidae]] (spiny turbots)
'''Suborder Pleuronectoidei'''
:Superfamily Citharoidea
:: [[Biology:Citharidae|Citharidae]] (largescale flounders)
:Superfamily Pleuronectoidea
:: [[Biology:Scophthalmidae|Scophthalmidae]] (turbots)
:: [[Biology:Paralichthyidae|Paralichthyidae]] (large-tooth flounders)
:: [[Biology:Pleuronectidae|Pleuronectidae]] (righteye flounders)
:: [[Biology:Bothidae|Bothidae]] (lefteye flounders)
:Superfamily Soleoidea
:: Paralichthodidae (measles flounders)
:: [[Biology:Poecilopsettidae|Poecilopsettidae]] (bigeye flounders)
:: [[Biology:Rhombosoleidae|Rhombosoleidae]] (rhombosoleids)
:: [[Biology:Achiropsettidae|Achiropsettidae]] (southern flounders)
:: [[Biology:Samaridae|Samaridae]] (crested flounders)
:: [[Biology:Achiridae|Achiridae]] (American soles)
:: [[Biology:Soleidae|Soleidae]] (true soles)
:: [[Biology:Cynoglossidae|Cynoglossidae]] (tonguefishes)
| type_species = ''Pleuronectes platessa''
| type_species_authority = [[Biography:Carl Linnaeus|Linnaeus]], [[Biology:10th edition of Systema Naturae|1758]]
}}

A '''flatfish''' is a member of the [[Biology:Ray-finned fish|ray-finned]] [[Biology:Demersal fish|demersal fish]] [[Biology:Order|order]] '''Pleuronectiformes''', also called the Heterosomata, sometimes classified as a suborder of [[Biology:Perciformes|Perciformes]].  In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward.

Many important food fish are in this order, including the [[Biology:Flounder|flounder]]s, soles, [[Biology:Turbot|turbot]], [[Biology:Plaice|plaice]], and [[Biology:Halibut|halibut]]. Some flatfish can [[Biology:Camouflage|camouflage]] themselves on the ocean floor.

==Taxonomy==
Over 800 described species are placed into 16 families.<ref name="ReferenceA">{{Cite journal|last1=Campbell|first1=Matthew A.|last2=Chanet|first2=Bruno|last3=Chen|first3=Jhen-Nien|last4=Lee|first4=Mao-Ying|last5=Chen|first5=Wei-Jen|date=2019|title=Origins and relationships of the Pleuronectoidei: Molecular and morphological analysis of living and fossil taxa|journal=Zoologica Scripta|language=en|volume=48|issue=5|pages=640–656|doi=10.1111/zsc.12372|s2cid=202856805|issn=0300-3256}}</ref> Broadly, the flatfishes are divided into two suborders, Psettodoidei and Pleuronectoidei, with > 99% of the species diversity found within the Pleuronectoidei.<ref>{{Cite book|title=Fishes of the world|last=Nelson, Joseph S. VerfasserIn.|isbn=9781118342336|oclc=958002567|date = 2016-03-28|publisher=John Wiley & Sons }}</ref> The largest families are [[Biology:Soleidae|Soleidae]], [[Biology:Bothidae|Bothidae]] and [[Biology:Tonguefish|Cynoglossidae]] with more than 150 species each. There also exist two monotypic families (Paralichthodidae and Oncopteridae). Some families are the results of relatively recent splits. For example, the [[Biology:Achiridae|Achiridae]] were classified as a subfamily of Soleidae in the past, and the [[Biology:Samaridae|Samaridae]] were considered a subfamily of the Pleuronectidae.<ref name="RandallHawaii">Randall, J. E. (2007). ''Reef and Shore Fishes of the Hawaiian Islands.'' {{ISBN|1-929054-03-3}}</ref><ref name="CopperChapleau">Cooper, J.A.; and Chapleau, F. (1998). ''Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification.'' Fish. Bull. 96 (4): 686–726.</ref> The families Paralichthodidae, [[Biology:Poecilopsettidae|Poecilopsettidae]], and [[Biology:Rhombosoleidae|Rhombosoleidae]] were also traditionally treated as subfamilies of Pleuronectidae, but are now recognised as families in their own right.<ref name=CopperChapleau/><ref name="Nelson-2006"/><ref name="NGW-2016"/> The [[Biology:Paralichthyidae|Paralichthyidae]] has long been indicated to be paraphyletic, with the formal description of Cyclopsettidae in 2019 resulting in the split of this family as well.<ref name="ReferenceA"/>

The [[Biology:Taxonomy|taxonomy]] of some groups is in need of a review, as the last [[Monograph|monograph]] covering the entire order was John Roxborough Norman's ''Monograph of the Flatfishes'' published in 1934. In particular, ''[[Biology:Tephrinectes sinensis|Tephrinectes sinensis]]'' may represent a family-level lineage and requires further evaluation e.g.<ref>{{Cite journal|last=Hoshino|first=Koichi|date=2001-11-01|title=Monophyly of the Citharidae (Pleuronectoidei: Pleuronectiformes: Teleostei) with considerations of pleuronectoid phylogeny|journal=Ichthyological Research|volume=48|issue=4|pages=391–404|doi=10.1007/s10228-001-8163-0|bibcode=2001IchtR..48..391H |s2cid=46318428|issn=1341-8998}}</ref>  New species are described with some regularity and undescribed species likely remain.<ref name=RandallHawaii/>

===Hybrids===
[[Biology:Hybrid|Hybrids]] are well known in flatfishes. The Pleuronectidae, of marine fishes, have the largest number of reported hybrids.<ref name=hybridsole>Garrett, D.L.; Pietsch, T.W.; Utter, F.M.; and Hauser, L. (2007). ''The Hybrid Sole Inopsetta ischyra (Teleostei: Pleuronectiformes: Pleuronectidae): Hybrid or Biological Species?'' American Fisheries Society 136: 460–468</ref> Two of the most famous [[Biology:Intergeneric hybrid|intergeneric hybrid]]s are between the [[Biology:European plaice|European plaice]] (''Pleuronectes platessa'') and [[Biology:European flounder|European flounder]] (''Platichthys flesus'') in the [[Place:Baltic Sea|Baltic Sea]],<ref>Food and Agriculture Organization of the United Nations: ''[http://www.fao.org/fishery/species/2550/en Platichthys flesus (Linnaeus, 1758).]''. Retrieved 18 May 2014</ref> and between the [[Biology:English sole|English sole]] (''Parophrys vetulus'') and [[Biology:Starry flounder|starry flounder]] (''Platichthys stellatus'') in Puget Sound. The offspring of the latter species pair is popularly known as the hybrid sole and was initially believed to be a valid species in its own right.<ref name=hybridsole/>

==Distribution==
Flatfishes are found in oceans worldwide, ranging from the Arctic, through the tropics, to [[Earth:Antarctica|Antarctica]]. Species diversity is centered in the Indo-West Pacific and declines following both latitudinal and longitudinal gradients away from the Indo-West Pacific.<ref>{{Cite journal|last1=Campbell|first1=Matthew A.|last2=Chanet|first2=Bruno|last3=Chen|first3=Jhen-Nien|last4=Lee|first4=Mao-Ying|last5=Chen|first5=Wei-Jen|date=2019|title=Origins and relationships of the Pleuronectoidei: Molecular and morphological analysis of living and fossil taxa|journal=Zoologica Scripta|language=en|volume=48|issue=5|pages=640–656|doi=10.1111/zsc.12372|s2cid=202856805|issn=1463-6409}}</ref> Most species are found in depths between 0 and {{convert|500|m|ft|abbr=on}}, but a few have been recorded from depths in excess of {{convert|1500|m|ft|abbr=on}}. None have been confirmed from the abyssal or [[Earth:Hadal zone|hadal zone]]s. An observation of a flatfish from the Bathyscaphe Trieste at the bottom of the Mariana Trench at a depth of almost {{convert|11|km|ft|abbr=on}} has been questioned by fish experts, and recent authorities do not recognize it as valid.<ref>Jamieson, A.J., and Yancey, P. H. (2012). ''[http://www.biolbull.org/content/222/3/171.full On the Validity of the Trieste Flatfish: Dispelling the Myth.]'' [[Biology:The Biological Bulletin|The Biological Bulletin]] 222(3): 171-175</ref> Among the deepwater species, ''[[Biology:Symphurus thermophilus|Symphurus thermophilus]]'' lives congregating around "ponds" of sulphur at [[Earth:Hydrothermal vent|hydrothermal vent]]s on the seafloor. No other flatfish is known from hydrothermal vents.<ref>Munroe, T.A.; and Hashimoto, J. (2008). ''A new Western Pacific Tonguefish (Pleuronectiformes: Cynoglossidae): The first Pleuronectiform discovered at active Hydrothermal Vents.'' Zootaxa 1839: 43–59.</ref> Many species will enter brackish or fresh water, and a smaller number of soles (families [[Biology:Achiridae|Achiridae]] and [[Biology:Soleidae|Soleidae]]) and tonguefish ([[Biology:Cynoglossidae|Cynoglossidae]]) are entirely restricted to fresh water.<ref>Duplain, R.R.; Chapleau, F; and Munroe, T.A. (2012). ''A New Species of Trinectes (Pleuronectiformes: Achiridae) from the Upper Río San Juan and Río Condoto, Colombia.'' Copeia 2012 (3): 541-546.</ref><ref>Kottelat, M. (1998). ''Fishes of the Nam Theun and Xe Bangfai basins, Laos, with diagnoses of twenty-two new species (Teleostei: Cyprinidae, Balitoridae, Cobitidae, Coiidae and Odontobutidae).'' Ichthyol. Explor. Freshwat. 9(1):1-128.</ref><ref>Monks, N. (2007). ''[http://brackishfaq.webspace.virginmedia.com/Projects/FAQ/4h.html Freshwater flatfish, order Pleuronectiformes.] {{Webarchive|url=https://web.archive.org/web/20140815222521/http://brackishfaq.webspace.virginmedia.com/Projects/FAQ/4h.html |date=2014-08-15 }}'' Retrieved 18 May 2014</ref>

==Characteristics==
[[File:Pseudopleuronectes americanus.jpg|thumb|left|Flatfish are asymmetric, with both eyes lying on the same side of the head]]
[[File:Platichthys flesus - en.pdf|thumb|left|European flounder, like other flatfish, experience an eye migration during their lifetime.]]
The most obvious characteristic of the flatfish is its [[Asymmetry|asymmetry]], with both eyes lying on the same side of the head in the adult fish. In some families, the eyes are usually on the right side of the body (dextral or right-eyed flatfish), and in others, they are usually on the left (sinistral or left-eyed flatfish). The primitive [[Biology:Spiny turbot|spiny turbot]]s include equal numbers of right- and left-sided individuals, and are generally less asymmetrical than the other families.<ref name=EoF/> Other distinguishing features of the order are the presence of protrusible eyes, another adaptation to living on the [[Earth:Seabed|seabed]] ([[Earth:Benthos|benthos]]), and the extension of the dorsal fin onto the head.

The surface of the fish facing away from the sea floor is pigmented, often serving to [[Biology:Camouflage|camouflage]] the fish, but sometimes with striking coloured patterns. Some flatfishes are also able to change their pigmentation to match the background, in a manner similar to some cephalopods. The side of the body without the eyes, facing the seabed, is usually colourless or very pale.<ref name=EoF>{{cite book |editor=Paxton, J.R. |editor2=Eschmeyer, W.N.|author1=Chapleau, Francois  |author2=Amaoka, Kunio|year=1998|title=Encyclopedia of Fishes|publisher= Academic Press|location=San Diego|pages= xxx|isbn= 0-12-547665-5 |no-pp=true}}</ref>

In general, flatfishes rely on their camouflage for avoiding predators, but some have [[Earth:Aposematism|aposematic]] traits such as conspicuous [[Biology:Eyespot (mimicry)|eyespots]] (e.g., ''Microchirus ocellatus'') and several small tropical species (at least ''[[Biology:Aseraggodes|Aseraggodes]]'', ''[[Biology:Pardachirus|Pardachirus]]'' and ''[[Biology:Zebrias|Zebrias]]'') are poisonous.<ref name=RandallHawaii/><ref>Elst, R. van der (1997) ''A Guide to the Common Sea Fishes of South Africa.'' {{ISBN|978-1868253944}}</ref><ref>Debelius, H. (1997). ''Mediterranean and Atlantic Fish Guide.'' {{ISBN|978-3925919541}}</ref> Juveniles of ''Soleichthys maculosus'' mimic toxic flatworms of the genus ''[[Biology:Pseudobiceros|Pseudobiceros]]'' in both colours and swimming mode.<ref>Practical Fishkeeping (22 May 2012) ''[http://www.practicalfishkeeping.co.uk/content.php?sid=5061 Video: Tiny sole mimics a flatworm.] {{Webarchive|url=https://web.archive.org/web/20140517213218/http://www.practicalfishkeeping.co.uk/content.php?sid=5061 |date=2014-05-17 }}'' Retrieved 17 May 2014.</ref><ref>Australian Museum (5 November 2010). ''[http://australianmuseum.net.au/BlogPost/Fish-Bits/This-week-in-Fish-Flatworm-mimic-and-shark-teeth This week in Fish: Flatworm mimic and shark teeth.] {{Webarchive|url=https://web.archive.org/web/20130226172618/http://australianmuseum.net.au/blogpost/Fish-Bits/This-week-in-Fish-Flatworm-mimic-and-shark-teeth |date=2013-02-26 }}'' Retrieved 17 May 2014.</ref>  Conversely, a few [[Biology:Octopus|octopus]] species have been reported to mimic flatfishes in colours, shape and swimming mode.<ref>Hanlon, R.T.; Warson, A.C.; and Barbosa, A. (2010). ''A "Mimic Octopus" in the Atlantic: Flatfish Mimicry and Camouflage by Macrotritopus defilippi.'' [[Biology:The Biological Bulletin|The Biological Bulletin]] 218(1): 15-24</ref>

The [[Biology:Flounder|flounder]]s and spiny turbots eat smaller fish, and have well-developed teeth. They sometimes seek prey in the midwater, away from the bottom, and show fewer extreme adaptations than other families. The soles, by contrast, are almost exclusively bottom-dwellers, and feed on invertebrates. They show a more extreme asymmetry, and may lack teeth on one side of the jaw.<ref name=EoF/>

Flatfishes range in size from ''Tarphops oligolepis'', measuring about {{convert|4.5|cm|in|abbr=on}} in length, and weighing {{convert|2|g|oz|abbr=on}}, to the [[Biology:Atlantic halibut|Atlantic halibut]], at {{convert|2.5|m|ft|abbr=on}} and {{convert|316|kg|lb|abbr=on}}.<ref name=EoF/>

 {{clear}}


==Species and species groups==
{{div col|colwidth=22em}}
* [[Biology:Brill (fish)|Brill]]
* [[Biology:Common dab|Dab]]
* Sanddab
* [[Biology:Flounder|Flounder]]
* [[Biology:Halibut|Halibut]]
* [[Biology:Megrim|Megrim]]
* [[Biology:Plaice|Plaice]]
* Sole
* [[Biology:Tonguefish|Tonguefish]]
* [[Biology:Turbot|Turbot]]
{{div col end}}

==Reproduction==
Flatfishes lay eggs that hatch into larvae resembling typical, symmetrical, fish. These are initially elongated, but quickly develop into a more rounded form. The larvae typically have protective spines on the head, over the gills, and in the pelvic and pectoral fins. They also possess a [[Biology:Swim bladder|swim bladder]], and do not dwell on the bottom, instead dispersing from their hatching grounds as [[Earth:Plankton|plankton]].<ref name=EoF/>

The length of the planktonic stage varies between different types of flatfishes, but eventually they begin to metamorphose into the adult form. One of the eyes migrates across the top of the head and onto the other side of the body, leaving the fish blind on one side. The larva also loses its swim bladder and spines, and sinks to the bottom, laying its blind side on the underlying surface.

==Evolution==
[[File:Amphistium.JPG|thumb|left|Fossil of ''Amphistium'']]

In 2008, a 50-million-year-old fossil, ''[[Biology:Amphistium|Amphistium]]'', was identified as an early relative of the flatfish and [[Biology:Transitional fossil|transitional fossil]].<ref name="NaEvo">{{cite news | url=http://news.nationalgeographic.com/news/2008/07/080709-evolution-fish.html  | archive-url=https://web.archive.org/web/20080711035445/http://news.nationalgeographic.com/news/2008/07/080709-evolution-fish.html  | url-status=dead  | archive-date=July 11, 2008  | title=Odd Fish Find Contradicts Intelligent-Design Argument  | publisher=[[Organization:National Geographic Society|National Geographic]] |date= July 9, 2008 | access-date =2008-07-17}}</ref> In a typical modern flatfish, the head is asymmetric, with both eyes on one side of the head. In ''Amphistium'', the transition from the typical symmetric head of a vertebrate is incomplete, with one eye placed near the top of the head.<ref>{{cite journal|author=Matt Friedman|title=The evolutionary origin of flatfish asymmetry| url=http://www.lacertilia.com/creationist_critiques/PDFs/Friedman_2008.pdf |archive-url=https://web.archive.org/web/20130319175318/http://www.lacertilia.com/creationist_critiques/PDFs/Friedman_2008.pdf |archive-date=2013-03-19 |url-status=live | journal=Nature Letters | volume=454| year=2008| pages=209–212| doi= 10.1038/nature07108| pmid=18615083|issue=7201|bibcode=2008Natur.454..209F|s2cid=4311712}}</ref> The researchers concluded,  "the change happened gradually, in a way consistent with evolution via [[Biology:Natural selection|natural selection]]—not suddenly, as researchers once had little choice but to believe."<ref name="NaEvo"/>

Flatfishes have been cited as dramatic examples of evolutionary adaptation. [[Biography:Richard Dawkins|Richard Dawkins]], in ''The Blind Watchmaker'', explains the flatfishes' evolutionary history thus:

<blockquote>...bony fish as a rule have a marked tendency to be flattened in a vertical direction.... It was natural, therefore, that when the ancestors of [flatfish] took to the sea bottom, they should have lain on one ''side''....  But this raised the problem that one eye was always looking down into the sand and was effectively useless. In evolution this problem was solved by the lower eye 'moving' round to the upper side.<ref>{{cite book
  | last = Dawkins
  | first = Richard
  | title = The Blind Watchmaker
  | publisher = Penguin Books
  | year = 1991
  | location = London
  |page=92
  | isbn = 0-14-014481-1}}</ref></blockquote>

{{clear}}

<gallery mode="packed">
File:Pleuronectes platessa.jpg|The [[Biology:European plaice|European plaice]] is the principal commercial flatfish in Europe.
File:Lined sole.jpg|American soles are found in both freshwater and marine environments of the Americas.
File:Alaska 2007 071.jpg|[[Biology:Halibut|Halibut]] are the largest of the flatfishes, and provide lucrative fisheries.
File:Psetta maxima Luc Viatour.jpg|The [[Biology:Turbot|turbot]] is a large, left-eyed flatfish found in sandy shallow coastal waters around Europe.
File:Flatfish-lefteyed-flounder.jpg|Flatfish (left‐eyed flounder)
</gallery>

==As food==
Flatfish is considered a Whitefish<ref>{{cite web|title=Flatfish BBC|url=https://www.bbc.co.uk/food/flatfish}}</ref> because of the high concentration of oils within its liver. Its lean flesh makes for a unique flavor that differs from species to species. Methods of cooking include grilling, pan-frying, baking and deep-frying.

==Timeline of genera==
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 color:eocene bar:NAM1  from:-55.8    till:-33.9 text:[[Biology:Amphistium|Amphistium]]
 color:eocene bar:NAM2  from:-55.8    till:-33.9 text:[[Biology:Eobothus|Eobothus]]
 color:eocene bar:NAM3  from:-55.8    till:-33.9 text:[[Biology:Eobuglossus|Eobuglossus]]
 color:eocene bar:NAM4 from:-55.8    till:-33.9 text:[[Biology:Imhoffius|Imhoffius]]
 color:eocene bar:NAM5 from:-55.8   till:-33.9 text:[[Biology:Joleaudichthys|Joleaudichthys]]
 color:eocene bar:NAM6 from:-55.8    till:-33.9 text:[[Biology:Turahbuglossus|Turahbuglossus]]
 color:eocene bar:NAM7 from:-55.8    till:0 text:[[Biology:Scophthalmus|Scophthalmus]]
 color:eocene bar:NAM8  from:-55.8    till:0 text:[[Biology:Citharus|Citharus]]
 color:eocene bar:NAM9  from:-55.8    till:0 text:[[Biology:Psettodes|Psettodes]]
 color:eocene bar:NAM10  from:-37.2 till:0 text:[[Biology:Arnoglossus|Arnoglossus]]
 color:oligocene bar:NAM11 from:-33.9 till:0 text:[[Biology:Bothus|Bothus]]
 color:oligocene bar:NAM12 from:-33.9 till:0 text:[[Biology:Monolene|Monolene]]
 color:oligocene bar:NAM13 from:-33.9 till:0 text:Solea
 color:oligocene bar:NAM14  from:-28.4 till:0 text:[[Biology:Buglossidium|Buglossidium]]
 color:oligocene bar:NAM15 from:-28.4 till:0 text:[[Biology:Hippoglossoides|Hippoglossoides]]
 color:oligocene bar:NAM16  from:-28.4 till:0 text:[[Biology:Lepidorhombus|Lepidorhombus]]
 color:miocene bar:NAM17  from:-23.03 till:0 text:Dicologoglossa
 color:miocene bar:NAM18  from:-23.03 till:0 text:[[Biology:Paraplagusia|Paraplagusia]]
 color:miocene bar:NAM19 from:-23.03 till:0 text:[[Biology:Platichthys|Platichthys]]
 color:miocene bar:NAM20 from:-15.97 till:0 text:Achiurus
 color:miocene bar:NAM21 from:-15.97 till:0 text:[[Biology:Microchirus|Microchirus]]
 color:miocene bar:NAM22 from:-15.97 till:0 text:[[Biology:Microstomus|Microstomus]]
 color:miocene bar:NAM23 from:-11.608   till:-5.332 text:[[Biology:Evesthes|Evesthes]]
 color:miocene bar:NAM24 from:-11.608   till:0 text:[[Biology:Citharichthys|Citharichthys]]
 color:miocene bar:NAM25 from:-11.608   till:0 text:[[Biology:Monochirus|Monochirus]]
 color:miocene bar:NAM26 from:-11.608   till:0 text:[[Biology:Paralichthys|Paralichthys]]
 color:miocene bar:NAM27 from:-11.608   till:0 text:[[Biology:Pleuronichthys|Pleuronichthys]]
 color:pliocene bar:NAM28 from:-5.332    till:0 text:[[Biology:Atheresthes|Atheresthes]]
 color:pliocene bar:NAM29 from:-5.332 till:0 text:[[Biology:Clidoderma|Clidoderma]]
 color:pliocene bar:NAM30 from:-5.332 till:0 text:[[Biology:Glyptocephalus|Glyptocephalus]]
 color:pliocene bar:NAM31 from:-5.332 till:0 text:[[Biology:Limanda|Limanda]]
 color:pliocene bar:NAM32 from:-5.332 till:0 text:[[Biology:Lyopsetta|Lyopsetta]]
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 color:pleistocene bar:NAM34 from:-2.588    till:-0.0117 text:Chibapsetta
 color:pleistocene bar:NAM35 from:-2.588    till:0 text:[[Biology:Eopsetta|Eopsetta]]
 color:pleistocene bar:NAM36 from:-2.588    till:0 text:[[Biology:Isopsetta|Isopsetta]]
 color:pleistocene bar:NAM37 from:-2.588    till:0 text:[[Biology:Parophrys|Parophrys]]
 color:pleistocene bar:NAM38 from:-2.588    till:0 text:[[Biology:Symphurus|Symphurus]]

PlotData=
 align:center textcolor:black fontsize:M mark:(line,black) width:25

 bar:period
 from: -65.5   till:  -55.8    color:paleocene  text:[[Earth:Paleocene|Paleocene]]
 from: -55.8   till:  -33.9    color:eocene  text:[[Earth:Eocene|Eocene]]
 from: -33.9   till:  -23.03    color:oligocene  text:[[Earth:Oligocene|Oligocene]]
 from: -23.03    till: -5.332    color:miocene    text:Miocene
 from: -5.332    till: -2.588    color:pliocene    text:Plio.
 from: -2.588    till: -0.0117   color:pleistocene    text:Pleist.
 from: -0.0117    till: 0    color:holocene    text:[[Earth:Holocene|H.]]

 bar:era
 from: -65.5   till:  -23.03    color:paleogene  text:[[Earth:Paleogene|Paleogene]]
 from: -23.03    till: -2.588    color:neogene    text:[[Earth:Neogene|Neogene]]
 from: -2.588    till: 0   color:quaternary    text:[[Earth:Quaternary|Q.]]
</timeline>

==See also==
* [[Sinistral and dextral]]

==References==
{{Reflist|28em}}

==Further reading==
* {{cite journal|last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera |journal=Bulletins of American Paleontology |volume=364 |page=560 |year=2002 |url=http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |access-date=2011-05-17 |url-status=dead |archive-url=https://web.archive.org/web/20110723131237/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |archive-date=July 23, 2011 }}
* Gibson, Robin N (Ed) (2008) Flatfishes: biology and exploitation. Wiley.
* Munroe, Thomas A  (2005) "Distributions and biogeography." Flatfishes: Biology and Exploitation: 42–67.

==External links==
*[http://www.dfo-mpo.gc.ca/science/publications/uww-msm/articles/plaice-plie-eng.htm Information on Canadian fisheries of plaice]

{{Commercial fish topics}}

{{Taxonbar|from=Q59577}}

[[Category:Pleuronectiformes| ]]
[[Category:Extant Paleocene first appearances]]
[[Category:Asymmetry]]

{{Sourceattribution|Flatfish}}