Utente:Marrabbio2/Pesci: differenze tra le versioni

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(13 versioni intermedie di 5 utenti non mostrate)
Riga 1:
[[File:Ostracoderm and placoderm.jpg|right|thumb|250px|I primi pesci fossili: [[ostracodermi]] (sopra) e [[Placodermi]]]]
{{Paraphyletic group
L'evoluzione dei pesci non è studiata come un singolo evento da quanto la riorganizzazione sistematica dei [[pesci]] ha portato al disconocimento di questi come gruppo monofiletico{{sfn|Lecointre|Le Guyader|2007|ps=}}.
|name = Fish
I primi pesci apparvero durante la cosidetta [[esplosione cambriana]], circa 530 milioni di anni fa: questi ritrovamenti [[fossili]] appartengono ad un gruppo di piccoli pesci corazzati senza mascelle, noti come [[ostracodermi]], oggi estinti. Un [[clade]] imparentato ed esistente, comprendente le [[Lampreda|lamprede]]. Le prime mascelle appaiono invece nei [[Placodermi]]. La diversità di questi vertebrati indica il vantaggio evolutivo di una [[bocca]] provvista di mascelle, anche se ancora non è chiaro chiaro se il vantaggio comprenda un morso con maggior resistenza, una respirazione migliorata o una combinazione di entrambi i fattori.
|fossil_range = {{fossilrange|Mid Cambrian|Recent|latest=0}}
|image_width = 250px
|image=Devonianfishes ntm 1905 smit 1929.gif
|image_caption=The [[Devonian]] period 419–359 [[mya (unit)|Ma]] or "Age of Fishes" saw the development of early sharks,<br />armoured [[placoderm]]s and various [[lobe-finned fish]]es<br />including the [[Rhipidistia|tetrapod transitional species]]
|regnum=[[Animal]]ia
|phylum=[[Chordata]]
|unranked_classis=[[Craniata]]
|includes =
:[[Agnatha|Jawless fish]]
:†[[Placodermi|Armoured fish]]
:[[Chondrichthyes|Cartilaginous fish]]
:[[Actinopterygii|Ray-finned fish]]
:[[Sarcopterygii|Lobe-finned fishes]]
|excludes=
:[[Tetrapoda|Tetrapods]]
}}
 
The '''evolution of fish''' is not studied as a single event since [[fish]] do not represent a [[monophyletic]] group.{{sfn|Lecointre|Le Guyader|2007|ps=}} Fish first appeared during the [[Cambrian explosion]], around {{Ma|530}} (Ma). Early fish from the [[fossil record]] are represented by a group of small, jawless, armoured fish known as [[Ostracoderm]]s. Jawless fish lineages are mostly extinct. An extant [[clade]], the [[Lamprey]]s may approximate ancient pre-jawed fish. The first jaws are found in [[Placodermi]] fossils. The diversity of jawed vertebrates may indicate the evolutionary advantage of a jawed [[mouth]]. It is unclear if the advantage of a hinged jaw is greater biting force, improved respiration, or a combination of factors.
__TOC__
{{clear}}
Riga 255 ⟶ 239:
|-
! rowspan=6 style=background:#708050 | [[Cambriano|<span style="color:white;">Cambriano</span>]]
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[CambrianCambriano]] (541–485542–488 [[myamilioni (unit)|Ma]]di anni fa): Thel'inizio beginningdel ofCambriano theè Cambriancaratterizzato wasdalla marked by thecosiddetta "[[CambrianEsplosione explosioncambriana]]", theun'improvvisa suddenapparizione appearancedi ofquasi nearlytutti alli of[[phyla]] theanimali invertebrate animal phylainvertebrati (molluscs[[molluschi]], jellyfish[[meduse]], worms[[vermi]] ande arthropods[[artropodi]], suchcome asi crustaceans[[crostacei]]) in greatgrande abundanceabbondanza. TheI firstprimi vertebratesvertebrati appearedapparvero in thesotto formforma ofdi primitivepesci fishprimitivi, whichche weresi subsequentlysono greatlyevoluti diversifiedpoi in themodo Silurianmolto anddiversificato Devoniannel [[Siluriano]] e [[Devoniano]].
|-
| [[File:Pikaia BW.jpg|140px]]
Riga 264 ⟶ 248:
| [[File:Haikouichthys 3d.png|140px]]
| ''[[Haikouichthys]]''
| ''[[Haikouichthys]]'' (il cui nome scientifico significa ''(fishpesce fromdi Haikou)'') isè anotherun genusaltro thatgenere alsoche appearsappare innei theritrovamenti fossilfossili recorddi aboutcirca 530 Mamilioni di anni fa, ande alsosegnala marksla thetransizione transitionda from[[invertebrati]] invertebratea to vertebrates.[[vetrebrati]]{{sfn|Shu2003}} Gli Haikouichthys areappartengono ai [[Craniata|craniatescraniati]] (animalsanimali withcon backbonesteschio ande distincttesta headsdistinta dal corpo). UnlikeDiversamente dai ''Pikaia'', theyvi hadè eyes.la Theypresenza alsodi hadocchi. aInoltre definedhanno skullun andteschio otherdefinito characteristicse thataltre havecaratteristiche ledche [[paleontology|paleontologists]]hanno toconvinto labeli itpaleontologi a trueclassificarli craniate,come andcraniati evene tocome beil popularlyprimo characterizedvero as one of the earliest fishespesce. [[Cladistics|CladisticAnalisi analysis]]cladistiche indicatessuccessive thathanno thesuggerito animalche isquesti probably aanimali basalfossero [[chordatechordata|cordati]] or a basalo [[craniatecraniata|craniati]]; {{r|Paleos: The Cambrian: 2}} butsenza itdare doesrisultati notindiscutibili possesse sufficientincontrovertibili, featurespertanto tosi befanno included uncontroversially evenrientrare in eitherentrambi [[stemi group]]gruppi.{{r|Donoghue2005}}{{sfn|Shu2003}}
|-
| [[File:Myllokunmingia.png|140px]]
| ''[[Myllokunmingia]]''
| ''[[Myllokunmingia]]'' è un genere apparso circa 530 milioni di anni fa. Apparteneva ai [[Cordata|cordati]], aveva dimensioni minute (28 mm di lunghezza e 6 di altezza) ed è tra le più antiche forme di vita [[vertebrati|vertebrate]].
| ''[[Myllokunmingia]]'' is a genus that appeared about 530 Ma. It is a chordate, and it has been argued that it is a [[vertebrate]],{{r|Shu1999}} It is 28&nbsp;mm long and 6&nbsp;mm high, and is among the oldest possible craniates.
|-
| [[File:Euconodonta.gif|140px]]
Riga 279 ⟶ 263:
|-
! rowspan=6 style=background:#20A090 | [[Ordoviciano|<span style="color:white;">Ordoviciano</span>]]
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[OrdovicianOrdoviciano]] (485–443488–443 Mamilioni di anni fa): Fishi pesci, thela world'sprima firstforma truedi vertebratesvita vertebrata, continuedcontinuano toad evolve,evolvere: andcompaiono thosei withprimi jawspesci con mandibole ([[Gnathostomata]]). may</br>La have first appeared late in this period.vita Lifesulla hadterraferma yetnon tosi diversifyè onancora landdifferenziata.
|-
| [[File:PteraspisLarnovaspis NTstensioei.jpg|140px]]
| [[Heterostraci]]
| [[Heterostraci]] è una classe estinta di agnati vertebrati che viveva principalmente in ambienti marini e di estuario. Sono apparsi all'inizio dell'Ordoviciano e si estinse alla fine del Devoniano. Differivano dagli altri pesci senza mandibola del periodo nella disposizione e nell'[[istologia]] delle loro [[scaglia|scaglie]].
| [[Heterostraci]] ''(different scales)'' is an extinct class of jawless vertebrate that lived primarily in marine and estuary environments. They appeared early in the Ordovician, and died out in the extinction event at the end of the Devonian. They differed from other jawless fish in the arrangement and [[histology]] of their [[Fish scale|scales]].
|-
| [[File:Astraspis desiderata.gif|center|110px]]
Riga 294 ⟶ 278:
|-
| [[File:Shielia tiati.svg|center|125px]]
| [[ThelodontsThelodonti]]
| [[Thelodonts]] ''(nipple teeth)'' are a class of small, extinct jawless fishes with distinctive scales instead of large plates of armour. There is debate over whether these represent a [[Monophyly|monophyletic grouping]], or disparate stem groups to the major lines of [[Agnatha|jawless]] and [[Gnathostome|jawed fish]].{{r|Turner1982}} Thelodonts are united by their characteristic "thelodont scales". This defining character is not necessarily a result of shared ancestry, as it may have been [[Convergent evolution|evolved independently by different groups]]. Thus the thelodonts are generally thought to represent a polyphyletic group.{{sfn|Sarjeant|Halstead}} If they are monophyletic, there is no firm evidence on what their ancestral state was.{{sfn|Donoghue|2000|p=206}} These scales were easily dispersed after death; their small size and resilience makes them the most common vertebrate fossil of their time.{{sfn|Turner1999|p=42–78}}{{r|Palaeos: Thelodonti}} The fish lived in both freshwater and marine environments, first appearing during the [[Ordovician]], and perishing during the [[Late Devonian extinction|Frasnian–Famennian extinction event]] of the Late [[Devonian]]. They were predominantly deposit-feeding bottom dwellers, although some species may have been pelagic.
|-
| colspan="3" style="line-height:16px; background:#dddddd;"| <small>The Ordovician ended with the [[Ordovician–Silurian extinction event]] (450–440 Ma). Two events occurred that killed off 27% of all families, 57% of all genera and 60% to 70% of all species.{{r|Baez2006}} Together they are ranked by many scientists as the second largest of the five major extinctions in Earth's history in terms of percentage of [[genus|genera]] that went extinct.</small>
|-
! rowspan=7 style=background:#60C090 | [[Siluriano]]
Riga 315 ⟶ 299:
|-
| [[File:Silurolepis platydorsalis.jpg|140px]]
| [[PlacodermPlacoderma]]s
| [[PlacodermPlacodermi]]s, ''(plate-like skin)'', are a group of armoured jawed fishes, of the class Placodermi. The oldest fossils appeared during the late Silurian, and became extinct at the end of the Devonian. Recent studies suggest that the placoderms are possibly a [[paraphyletic]] group of [[Basal (phylogenetics)|basal]] jawed fishes, and the closest relatives of all living jawed vertebrates. Some placoderms were small, flattened bottom-dwellers, such as [[antiarch]]s. However many, particularly the arthrodires, were active midwater predators. ''[[Dunkleosteus]]'', which appeared later in the Devonian below, was the largest and most famous of these. The upper jaw was firmly fused to the skull, but there was a hinge joint between the skull and the bony plating of the trunk region. This allowed the upper part of the head to be thrown back and, in [[arthrodire]]s, allowed them to take larger bites.
|-
| [[File:Guiyu BW.jpg|140px]]
| ''[[Guiyu oneiros]]''
| ''[[Guiyu oneiros]]'', theè earliestil knownpiù bonyantico fishpesce osseo oggi conosciuto. ItPresenta hasuna thecombinazione combinationdi ofcaratteri bothtipici degli [[Actinopterygii|ray-finned]] ande dei [[Sarcopterygii|lobe-finned]] features, although analysis of theanche totalityse ofl'analisi itsscientifica featureslo placepone itpiù closervicino toa lobe-finnedquesti fishultimi.{{r|Zhu2009}}{{r|Coates2009}}{{r|SL2009}}{{r|SB2009}}
|-
|
| [[File:Andreolepis hedei.jpg|140px]]
| ''[[Andreolepis]]''
| TheIl extinct genusgenere ''[[Andreolepis]]'' includesinclude theil earliestpiù knownantico ray[[Actinopterygii|attinopterigio]] finnedoggi fishconosciuto, ''[[Andreolepis hedei]]'', whichche appearedcomparve innel thetardo late Silurian[[Siluriano]], aroundcirca 420 Mamilioni di anni fa.<ref>{{cite journal | author = Min Z | year = 1997 | title = The oldest sarcopterygian fish | url = http://www.researchgate.net/publication/225089993_The_oldest_sarcopterygian_fish/file/d912f4fcb0d2e1d901.pdf | format = PDF | journal = Lethaia | volume = 30 | issue = | pages = 293–304 }}</ref><ref>{{cite journal | author = Märss T | year = 2001 | title = ''Andreolepis'' (Actinopterygii) in the upper Silurian of northern Eurasia | url = http://books.google.co.nz/books?id=0D3ucZP97e4C&pg=PA174&dq=%22Andreolepis+%28Actinopterygii%29+in+the+upper+Silurian+of+northern+Eurasia%22&hl=en&sa=X&ei=tF8IUeHwHYH-lAWo_IGwBA&ved=0CC8Q6AEwAA#v=onepage&q=%22Andreolepis%20%28Actinopterygii%29%20in%20the%20upper%20Silurian%20of%20northern%20Eurasia%22&f=false | journal = Proceedings of the Estonian Academy of Sciences | volume = 50 | issue = 3| pages = 174–189 }}</ref>
|}
 
Riga 352 ⟶ 336:
| colspan="5" |
|-
! rowspan=18 style=background:#CD9C50 | <div align="center">'''[[Devoniano|D<br>e<br>v<br>o<br>n<br>i<br>a<br>n<br>o]]'''</centerdiv>
| rowspan=6 style=background:#FFC060 | <div align="center">[[Devoniano inferiore]]</centerdiv>
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[Devoniano inferiore]] (419–393 Ma):
|-
Riga 376 ⟶ 360:
| ''[[Laccognathus]]'' ''(pitted jaw)'' was a genus of [[amphibious fish|amphibious]] lobe-finned fish that existed 398–360 Ma.<ref name="ngs">{{cite web|url=http://news.nationalgeographic.com/news/2011/09/110912-ancient-fish-arctic-predator-devonian-fossils-animals-science/|title=Ancient Toothy Fish Found in Arctic—Giant Prowled Rivers|author=[[Christine Dell'Amore|Dell'Amore, C.]]|date=September 12, 2011|publisher=[[National Geographic Society|National Geographic]] Daily News|accessdate=September 13, 2011}}</ref> They were characterized by the three large pits (fossae) on the external surface of the lower jaw which may have had sensory functions.<ref name="avril">{{cite web|url=http://articles.philly.com/2011-09-12/news/30145487_1_tiktaalik-roseae-ted-daeschler/2|title=Fish fossil sheds light on 'Euramerica' phase|author=Tom Avril|date=September 12, 2011|publisher=The Inquirer|accessdate=September 15, 2011}}</ref> ''Laccognathus'' grew to {{convert|1|-|2|m|ft|0}} in length. They had very short dorsoventrally flattened heads, less than one-fifth the length of the body.<ref name="vorobyeva">{{cite journal|author=[[Emiliya Ivanovna Vorobyeva|Vorobyeva, E.I.]]|year=2006|title=A new species of ''Laccognathus'' (Porolepiform Crossopterygii) from the Devonian of Latvia |journal=[[Paleontological Journal|Palaeont. J.]]|volume=40|issue=3|pages=312&ndash;322|publisher=Physorg.com|doi=10.1134/S0031030106030129}}</ref> The skeleton was structured so large areas of skin were stretched over solid plates of bone. This bone was composed of particularly dense fibers – so dense that exchange of oxygen through the skin was unlikely. Rather, the dense [[ossification]]s served to retain water inside the body as ''Laccognathus'' traveled on land between bodies of water.<ref name = "witzmann">{{cite journal|author=[[Florian Witzman|Witzman, F.]]|journal=[[Paleodiversity]]|volume=31|issue=5|pages=981–996|year=2011|publisher=The Society of Vertebrate Paleontology|title=A New Species of ''Laccognathus'' (Sarcopterygii, Porolepiformes) from the Late Devonian of Ellesmere Island, Nunavut, Canada}}</ref>
|-
| rowspan=7 style=background:#FFD090 | <div align="center">[[Devoniano medio]]</centerdiv>
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[Devoniano medio]] (397–385 Ma): [[Chondrichthyes|Cartilaginous fishes]], consisting of [[shark]]s, [[Batoidea|rays]] and [[chimaera]]s, appeared about 395 Ma.
|-
Riga 391 ⟶ 375:
| ''[[Coccosteus]]'' ''(seed bone)'' is an extinct genus of [[arthrodire]] [[placoderm]]. The majority of fossils have been found in freshwater sediments, though they may have been able to enter saltwater. They grew up to {{convert|40|cm|in}} long. Like all other arthrodires, ''Coccosteus'' had a joint between the armour of the body and skull. In addition, it also had an internal joint between its neck [[vertebrae]] and the back of the skull, allowing for the mouth to be opened even wider. Along with the longer jaws, this allowed ''Coccosteus'' to feed on fairly large prey. As with all other arthrodires, ''Coccosteus'' had bony dental plates embedded in its jaws, forming a beak. The beak was kept sharp by having the edges of the dental plates grind away at each other.{{sfn|The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|1999|p=32}}
|-
| [[File:Bothriolepis canadensis 2.jpg|center|120px]]<small>Citron</small>
| ''[[Bothriolepis]]''
|
| {{ external media
''[[Bothriolepis]]'' è stato il genere di [[placodermi]] più diffuso nei ritrovamenti fossili, con oltre 100 specie scoperte negli strati rocciosi del Devoniano medio in ogni continente.
| align =
| width = 200px
| video1 = [http://animal.discovery.com/tv-shows/other/videos/animal-armageddon-bothriopelis ''Bothriolepis''] – ''Animal Planet''
}}
''[[Bothriolepis]]'' ''(pitted scale)'' was the most successful genus of [[antiarch]] [[placoderms]], if not the most successful genus of any placoderm, with over 100 species spread across Middle to Late Devonian strata across every continent.
|-
| [[File:Pituriaspis doylei.jpg|center|80px]]
Riga 406 ⟶ 386:
| colspan="3" style="line-height:16px; background:#dddddd;"| <small>[[Late Devonian extinction]]: 375–360 Ma. A prolonged series of extinctions eliminated about 19% of all families, 50% of all genera{{r|Baez2006}} and 70% of all species. This extinction event lasted perhaps as long as 20 Ma, and there is evidence for a series of extinction pulses within this period.</small>
|-
| rowspan=5 style=background:#FFE0B0 | <div align="center">[[Devoniano superiore]]</centerdiv>
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[Devoniano superiore]] (383–359 Ma):
|-
| [[File:Dunkleosteus interm1DBintermedius.jpg|140px]]
| ''[[Dunkleosteus]]''
| {{ external media
Riga 431 ⟶ 411:
''[[Materpiscis]]'' ''(mother fish)'' is a [[genus]] of [[ptyctodontid]] [[Placodermi|placoderm]] from about 380 Ma. Known from only one specimen, it is unique in having an unborn [[embryo]] present inside, and with remarkable preservation of a mineralised placental feeding structure ([[umbilical cord]]). This makes ''Materpiscis'' the first known vertebrate to show [[vivipary|viviparity]], or giving birth to live young.{{r|Long2008}} The specimen was named ''Materpiscis attenboroughi'' in honour of [[David Attenborough]].{{r|BBC2008}}
|-
|
| [[File:Gooloogongia.jpg|140px]]
| [[Rhizodont]]s
| [[Rhizodont]]s were an order of lobe-finned fish which survived to the end of the Carboniferous, 377–310 Ma. They reached huge sizes. The largest known species, ''[[Rhizodus|Rhizodus hibberti]]'' grew up to 7 metres in length, making it the largest freshwater fish known.
Riga 507 ⟶ 487:
! colspan=4 | Transition from lobe-finned fishes to tetrapods
|-
| [[File:Eusthenopteron model.jpg|140px]]<small>~385 milioni di anni fa</small>
| ''[[Eusthenopteron]]''
| {{ external media
Riga 520 ⟶ 500:
| ''[[Gogonasus]] (snout from Gogo)'' was a lobe-finned fish known from 3-dimensionally preserved 380 million-year-old fossils found in the [[Gogo Formation]]. It was a small fish reaching 30–40&nbsp;cm (1&nbsp;ft) in length.<ref>http://dinosaurs.about.com/od/tetrapodsandamphibians/p/gogonasus.htm</ref> Its skeleton shows several tetrapod-like features. They included the structure of its [[middle ear]], and its fins show the precursors of the forearm bones, the [[radius]] and [[ulna]]. Researchers believe it used its forearm-like fins to dart out of the reef to catch prey. ''Gogonasus'' was first described in 1985 by [[John A. Long]]. For almost 100 years ''[[Eusthenopteron]]'' has been the role model for demonstrating stages in the evolution of lobe-finned fishes to tetrapods. ''Gogonasus'' now replaces ''Eusthenopteron'' in being a better preserved representative without any ambiguity in interpreting its anatomy.
|-
| [[File:Panderichthys BW.jpg|140px]]<br /><small>~385 milioni di anni fa</small>
| ''[[Panderichthys]]''
| Adapted to muddy shallows, and capable of some kind of shallow water or terrestrial body flexion locomotion. Had the ability to prop itself up.<ref>Nature: [http://www.nature.com/nature/journal/v438/n7071/edsumm/e051222-13.html The pelvic fin and girdle of ''Panderichthys'' and the origin of tetrapod locomotion]</ref><br /> They had large tetrapod-like heads, and are thought to be the most crownward stem fish-tetrapod with paired fins.
|-
| [[File:Tiktaalik BW.jpg|140px]]<br /><small>~375 milioni di anni fa</small>
| ''[[Tiktaalik]]''
| A fish with limb-like fins that could take it onto land.<ref name=Nature>{{cite journal | journal = [[Nature (journal)|Nature]] | volume = 440 | pages = 757–763 | date = 6 April 2006 | doi = 10.1038/nature04639 | title = A Devonian tetrapod-like fish and the evolution of the tetrapod body plan | url = http://www.nature.com/nature/journal/v440/n7085/abs/nature04639.html | author = Edward B. Daeschler, Neil H. Shubin and Farish A. Jenkins, Jr | pmid = 16598249 | issue = 7085}}</ref> It is an example from several lines of ancient sarcopterygian fish developing adaptations to the oxygen-poor shallow-water habitats of its time, which led to the evolution of tetrapods.<ref name="scientificamerican">[[Jennifer A. Clack]], ''Scientific American'', [http://www.scientificamerican.com/article.cfm?id=getting-a-leg-up-on-land ''Getting a Leg Up on Land''] Nov. 21, 2005.</ref> Paleontologists suggest that it is representative of the [[transitional fossil|transition]] between non-tetrapod vertebrates (fish) such as ''[[Panderichthys]]'', known from fossils 380 million years old, and early tetrapods such as ''[[Acanthostega]]'' and ''[[Ichthyostega]]'', known from fossils about 365 million years old. Its mixture of primitive fish and derived tetrapod characteristics led one of its discoverers, [[Neil Shubin]], to characterize ''Tiktaalik'' as a "[[Tetrapodomorpha|fishapod]]".<ref>John Noble Wilford, ''The New York Times'', [http://www.nytimes.com/2006/04/05/science/05cnd-fossil.html?hp&ex=1144296000&en=fe3427d67e965e46&ei=5094&partner=homepage ''Scientists Call Fish Fossil the Missing Link''], Apr. 5, 2006.</ref><ref name="Shubin 2008">{{cite book|last=Shubin|first=Neil|title=Your Inner Fish|publisher=Pantheon|year=2008|isbn=978-0-375-42447-2}}</ref>
|-
| [[File:Acanthostega BW.jpg|140px]]<br /><small>365 milioni di anni fa</small>
| ''[[Acanthostega]]''
| A fish-like early [[Labyrinthodontia|labyrinthodont]] which occupied weed-filled swamps and changed views about the early evolution of tetrapods.{{r|Clack2005}} [[Polydactyly in early tetrapods|It had eight digits]] on each hand (the number of digits on the feet is unclear) linked by webbing, it lacked wrists, and was generally poorly adapted to come onto land.<ref>"[http://www.devoniantimes.org/Order/re-acanthostega.html Acanthostega gunneri]," ''Devonian Times''.</ref> Sunsequent discoveries revealed earlier transitional forms between ''Acanthostega'' and completely fish-like animals.{{r|Daeschler2006}}
 
|-
| [[File:Ichthyostega BW.jpg|140px]]<br /><small>374–359 milioni di anni fa</small>
| ''[[Ichthyostega]]''
| {{ external media
Riga 542 ⟶ 522:
Until finds of other early tetrapods and closely related fishes in the late 20th century, ''[[Ichthyostega]]'' stood alone as the transitional fossil between fish and tetrapods, combining a fishlike tail and gills with an amphibian skull and limbs. It possessed lungs and limbs with seven digits that helped it navigate through shallow water in weed-filled swamps.
|-
| [[File:Pederpes22small.jpg|140px]]<br /><small>359–345 milioni di anni fa</small>
| ''[[Pederpes]]''
| ''[[Pederpes]]'' is the earliest known fully terrestrial tetrapod. It is included here to complete the transition of lobe-finned fishes to tetrapods, even though ''Pederpes'' is no longer a fish.
Riga 553 ⟶ 533:
 
===Post-Devoniano===
L'[[Mesozoico|Era Mesozoica]] inizia circa 250 milioni di anni fa sulla scia dell'[[Estinzione di massa del Permiano-Triassico]], la più grande [[estinzione]] della storia della [[Terra]], e finisce circa 65 milioni di anni fa, con l'[[Estinzione di massa del Cretaceo-Paleocene]], un'altra estinzione massiva che uccise i [[dinosauri]] e moltre specie di piante e animali. É spesso definita come l'''età dei rettili'', perché i rettili sono stati i vertebrati dominanti in questa era. Durante il Mesozoico inoltre il maxicontinente [[Pangea]] si divide gradualmente in continenti più piccoli. Il clima alterna periodi molto caldi a periodi più freddi, ma nel complesso la Terra era più calda di quanto non lo sia oggi.
 
* The [[Mesozoic Era]] began about 250 million years ago in the wake of the [[Permian-Triassic event]], the largest [[mass extinction]] in Earth's history, and ended about 65 million years ago with the [[Cretaceous–Paleogene extinction event]], another mass extinction which killed off non-avian [[dinosaur]]s, as well as other plant and animal species. It is often referred to as the ''Age of Reptiles'' because reptiles were the dominant vertebrates of the time. The Mesozoic witnessed the gradual rifting of the supercontinent [[Pangaea]] into separate landmasses. The climate alternated between warming and cooling periods; overall the Earth was hotter than it is today.
 
{| class="wikitable"
Riga 576 ⟶ 555:
| [[File:Falcatus.jpg|140px]]
| ''[[Falcatus]]''
| ''[[Falcatus]]'' isè aun genusgenere ofdi smallpiccoli cladodont-toothedcladodonti sharksdai whichdenti livedappuntiti 335–318e Masqualiformi, che vissero da 335 a 318 milioni di anni fa. TheyDi piccole dimensioni, wereraggiungevano abouti 25-30 cm (10-12di inches) longlunghezza. <ref>Pesci fossili [http://www.sju.edu/research/bear_gulch/pages_fish_species/Falcatus_falcatus.php Fossil Fish ofdi Bear Gulch 2005 byda Richard Lund ande Eileen Grogan] Accessed 2009-01-14</ref> TheySono caratterizzati dalla areparticolare characterisedforma bydella thepinna prominentdorsale, finche spinespresenta thati curvedraggi anteriorlyincurvati oververso theirla headstesta.
|-
| [[File:Orodus sp1DB.jpg|140px]]
| ''[[Orodus]]''
| ''[[Orodus]]'' isè anotherun sharkaltro ofgenere thedi Carboniferous,[[squalo]] adel genusCarbonifero, fromappartenenti thealla familyfamiglia [[Orodontidae]], thatvissuto lived into the early Permian fromda 303 toa 295 Ma.milioni Itdi grewanni tofa. 2Raggiungeva muna (7lunghezza ft)di in2 lengthmetri.
|-
! rowspan=3 style=background:#ED4C35 | [[Permiano]]
Riga 589 ⟶ 568:
| ''[[Acanthodes]]'' are an extinct genus of [[Acanthodii|spiny shark]].<ref>{{cite journal|year=1880|title=Proceedings of the Royal Physical Society of Edinburgh|volume= V.|pages=p115|url=http://books.google.com/?id=69kKAAAAIAAJ&pg=PA115&dq=Acanthodes+extinct|doi=10.1111/|author1=Edinburgh, Royal Physical Society of}}</ref> It had [[gill]]s but no [[teeth]],<ref name="Nicholson">{{cite book|last=Nicholson|first=Henry Alleyne|coauthors=Richard Lydekker|title=A Manual of Palaeontology|year=1889|url=http://books.google.com/?id=MoAXAAAAYAAJ&pg=PA966&dq=Acanthodes+pectoral+fins|page=966}}</ref> and was presumably a [[filter feeder]].<ref name=EoDP/> ''Acanthodes'' had only two skull bones and were covered in cubical scales. Each paired [[pectoral fin|pectoral]] and [[pelvic fin]]s had one spine, as did the single [[anal fin|anal]] and [[dorsal fin]]s, giving it a total of six spines, less than half that of many other spiny sharks.<ref name=EoDP>{{cite book |editor=Palmer, D.|year=1999 |title= The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|publisher= Marshall Editions|___location=London|pages= 30–31|isbn= 1-84028-152-9}}</ref> Acanthodians share qualities of both bony fish (osteichthyes) and cartilaginous fish (chondrichthyes), and it has been suggested that they may have been stem chondrichthyans and stem gnathostomes.<ref>Article on Acanthodes as ancestor of Man, http://www.sci-news.com/paleontology/article00396.html, accessed 15 June 2012</ref><ref>Journal article on Acanthodes, http://www.nature.com/nature/journal/v486/n7402/full/nature11080.html, accessed 15 June 2012</ref>
|-
| colspan="3" style="line-height:16px; background:#dddddd;"| <small>The Permian ended with the most extensive [[extinction event]] recorded in [[paleontology]]: the [[Permian-Triassic extinction event]]. 90% to 95% of marine species became [[Extinction|extinct]], as well as 70% of all land organisms. It is also the only known mass extinction of insects.<ref>http://geology.about.com/od/extinction/a/aa_permotrias.htm</ref><ref>http://www.kgs.ku.edu/Extension/fossils/massExtinct.html</ref> Recovery from the Permian-Triassic extinction event was protracted; land ecosystems took 30M years to recover,<ref name="SahneyBenton2008RecoveryFromProfoundExtinction">{{cite journal | url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2596898/?tool | author=Sahney, S. and Benton, M.J. | year=2008 | title=Recovery from the most profound mass extinction of all time | journal=Proceedings of the Royal Society: Biological | doi=10.1098/rspb.2007.1370 | volume = 275 | pages = 759–65|format=PDF | pmid=18198148 | issue=1636 | pmc=2596898}}</ref> and marine ecosystems took even longer.{{r|Baez2006}}</small>
|-
! rowspan=5 style="background:#228b22" | [[Triassico|<span style="color:white;">Triassico</span>]]
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[Triassico]] (252–201 Ma): The fish fauna of the Triassic was remarkably uniform, reflecting the fact that very few families survived the Permian extinction. A considerable radiation of ''ray-finned fishes]]'' occurred during the Triassic, laying the foundation for many modern fishes.<ref>[http://www.seaworld.org/animal-info/info-books/bony-fish/scientific-classification.htm Bony fishes] ''[[SeaWorld]]''. Retrieved 2 February 2013.</ref> ''See [[:Category:Triassic fish]].''
|-
| [[File:Perleidus.jpg|140px]]
Riga 607 ⟶ 586:
| ''[[Pholidophorus]]'' was an [[extinct]] genus of [[teleost]], around {{convert|40|cm|in}} long, from about 240–140 Ma. Although not closely related to the modern [[herring]], it was somewhat like them. It had a single [[dorsal fin]], a symmetrical tail, and an [[anal fin]] placed towards the rear of the body. It had large eyes and was probably a fast swimming predator, hunting [[plankton]]ic [[crustacean]]s and smaller fish.{{sfn|The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|1999|p=38–39}} A very early [[teleost]], ''Pholidophoris'' had many primitive characteristics such as [[ganoid scale]]s and a [[Vertebral column|spine]] that was partially composed of [[cartilage]], rather than [[bone]].{{sfn|The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|1999|p=38–39}}
|-
| colspan="3" style="line-height:16px; background:#dddddd;"| <small>The Triassic ended with the [[Triassic–Jurassic extinction event]]. About 23% of all families, 48% of all genera (20% of marine families and 55% of marine genera) and 70% to 75% of all species went extinct.<ref name="ucr">{{cite web|url=http://math.ucr.edu/home/baez/extinction |title=extinction |publisher=Math.ucr.edu |date= |accessdate=2008-11-09}}</ref> Non-dinosaurian archosaurs continued to dominate aquatic environments, while [[Diapsid#Taxonomy|non-archosaurian diapsids]] continued to dominate marine environments.<ref name="ucr" /></small>
|-
! rowspan=3 style="background:#3cb371" | [[Giurassico]]
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[JurassicoGiurassico]] (201–145199–145 Mamilioni di anni fa):
|-
| [[File:Leedsichthys new1DBproblematicus.jpg|140px]]
| ''[[Leedsichthys]]''
| During the [[Jurassic period]], the primary vertebrates living in the seas were [[fish]] and marine [[reptile]]s. The latter include [[ichthyosaur]]s who were at the peak of their diversity, [[plesiosauria|plesiosaurs]], [[pliosaur]]s, and marine [[crocodilia|crocodiles]] of the families [[Teleosauridae]] and [[Metriorhynchidae]].<ref>Motani, R. (2000), Rulers of the Jurassic Seas, Scientific American vol.283, no. 6</ref> Numerous [[turtle]]s could be found in lakes and rivers.<ref name=nws>{{citation
Riga 638 ⟶ 617:
|-
! rowspan=5 style="background:#32cd32" | [[Cretacico]]
| colspan="3" style="text-align:center; background:#ddf8f8;"| [[Cretacico]] (145–66145–65 Ma):milioni ''Seedi [[:Category:Cretaceousanni fish]].''fa)
|-
| [[File:Sturgeon2Acipenser ruthenus Prague Vltava 1.jpg|140px]]
| ''[[SturgeonAcipenseridae|Storioni]]''
| TrueGli [[sturgeon]]sstorioni appearappaiono innei theritrovamenti fossilfossili recordnel duringCretacico thesuperiore Uppere, Cretaceous.da Sincequel that timemomento, sturgeonsla haveloro undergonemorfologia remarkablyha littlesubito [[morphologyben (biology)|morphological]]pochi changecambiamenti evolutivi, indicating their evolution has been exceptionally slow and earningdando themloro informallo status asdi [[livingfossile fossilsvivente|fossili viventi]].<ref>B. G. Gardiner (1984) Sturgeons as living fossils. Pp. 148–152 in N. Eldredge and S.M. Stanley, eds. Living fossils. Springer-Verlag, New York.</ref><ref name=krieger>{{cite journal | author = Krieger J., Fuerst P.A. | year = 2002 | title = Evidence for a Slowed Rate of Molecular Evolution in the Order Acipenseriformes | url = | journal = Molecular Biology and Evolution | volume = 19 | issue = | pages = 891–897 }}</ref> This is explained in part by the long generation interval, tolerance for wide ranges of [[temperature]] and [[salinity]], lack of [[Predation|predators]] due to size, and the abundance of prey items in the [[benthic]] environment. </br>
La loro lentissima evoluzione è dovuta ad alcuni fattori fondamentali: un lungo intervallo generazionale, un'ampia tolleranza alle diverse temperature e salinità delle acque, la mancanza di predatori a causa delle loro grosse dimensioni e l'abbondanza di prede nel loro ambiente.
|-
| [[File:Enchodus2Enchodus petrosus.jpg|140px]]
| ''[[Enchodus]]''
|
Riga 650 ⟶ 630:
| [[File:Xiphactinus audax fossil.jpg|140px]]
| ''[[Xiphactinus]]''
|
| {{ external media
"OneIl Cretaceouspiù fish,grande dei ''[[Xiphactinusteleostei]]'' conosciuti, grewquesto topesce moredel thanCretacico 4.5raggiungeva metresuna (15lunghezza feet)di and4,5 ismetri the largest known [[teleost]]."<ref>Rafferty, John P (2010) [http://books.google.co.nz/books?id=kFd-1DApcRYC&pg=PA219&dq=%22Cretaceous+fish%22+OR+%22Cretaceous+fishes%22&hl=en&sa=X&ei=HkrtUNPWHonKlAWshYGQBQ&ved=0CKEBEOgBMBM#v=onepage&q=%22Cretaceous%20fish%22%20OR%20%22Cretaceous%20fishes%22&f=false ''The Mesozoic Era: Age of Dinosaurs''] Pagepag. 219, Rosen Publishing Group. ISBN 9781615301935.</ref>.
| align =
| width = 250px
| video1 = [http://www.youtube.com/watch?v=Jla2g1iM8tE ''Xiphactinus''] – ''YouTube''}}
 
"One Cretaceous fish, ''[[Xiphactinus]]'', grew to more than 4.5 metres (15 feet) and is the largest known [[teleost]]."<ref>Rafferty, John P (2010) [http://books.google.co.nz/books?id=kFd-1DApcRYC&pg=PA219&dq=%22Cretaceous+fish%22+OR+%22Cretaceous+fishes%22&hl=en&sa=X&ei=HkrtUNPWHonKlAWshYGQBQ&ved=0CKEBEOgBMBM#v=onepage&q=%22Cretaceous%20fish%22%20OR%20%22Cretaceous%20fishes%22&f=false ''The Mesozoic Era: Age of Dinosaurs''] Page 219, Rosen Publishing Group. ISBN 9781615301935.</ref>
|-
| colspan="3" style="line-height:16px; background:#dddddd;"| <small>The end of the Cretaceous was marked by the [[Cretaceous–Paleogene extinction event]] (K-Pg extinction). There are substantial fossil records of [[Gnathostomata|jawed]] [[fish]]es across the K–T boundary, which provides good evidence of extinction patterns of these classes of marine vertebrates. Within [[Chondrichthyes|cartilaginous fish]], approximately 80% of the [[shark]]s, [[Rajiformes|rays]], and [[skate]]s families survived the extinction event,<ref name="MacLeod">{{cite journal|author=MacLeod, N, Rawson, PF, Forey, PL, Banner, FT, Boudagher-Fadel, MK, Bown, PR, Burnett, JA, Chambers, P, Culver, S, Evans, SE, Jeffery, C, Kaminski, MA, Lord, AR, Milner, AC, Milner, AR, Morris, N, Owen, E, Rosen, BR, Smith, AB, Taylor, PD, Urquhart, E & Young, JR|title=The Cretaceous–Tertiary biotic transition|year=1997|journal=Journal of the Geological Society|volume=154|issue=2|pages=265–292|url=http://findarticles.com/p/articles/mi_qa3721/is_199703/ai_n8738406/print|doi=10.1144/gsjgs.154.2.0265}}</ref> and more than 90% of [[teleostei|teleost fish]] (bony fish) families survived.<ref>{{cite book |last=Patterson|first=C |year=1993 |title=Osteichthyes: Teleostei. In: The Fossil Record 2 (Benton, MJ, editor) |publisher=Springer |pages=621–656 |isbn=0-412-39380-8}}</ref> There is evidence of a mass kill of bony fishes at a fossil site immediately above the K–T boundary layer on [[Seymour Island]] near Antarctica, apparently precipitated by the K–Pg extinction event.<ref>{{cite journal |title=Discovery of fish mortality horizon at the K–T boundary on Seymour Island: Re-evaluation of events at the end of the Cretaceous |author=Zinsmeister WJ |date=1 May 1998|url=http://jpaleontol.geoscienceworld.org/cgi/content/abstract/72/3/556?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=zinsmeister&andorexacttitle=and&field_name=fulltext&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=7/1/1927&tdate=7/31/2007&resourcetype=HWCIT |accessdate=2007-08-27 |journal=Journal of Paleontology |volume=72 |issue=3 |pages=556–571 }}</ref> However, the marine and freshwater environments of fishes mitigated environmental effects of the extinction event.<ref name="Robertson">{{cite journal |title= Survival in the first hours of the Cenozoic |author=Robertson DS, McKenna MC, Toon OB, Hope S, Lillegraven JA |journal=GSA Bulletin |year=2004 |volume=116 |issue=5–6 |pages=760–768 |doi=10.1130/B25402.1 |url=http://www.ugcs.caltech.edu/~presto/cenozoic.pdf |format=PDF|accessdate=2007-08-31}}</ref></small>
|-
! rowspan=3 style="background:#FFFF00" | [[Cenozoico]]
Riga 666 ⟶ 642:
| ''[[Amphistium]]'' is a 50-million-year-old fossil fish which has been identified as an early relative of the flatfish, and as a transitional fossil.<ref name="NaEvo">{{cite news | url=http://news.nationalgeographic.com/news/2008/07/080709-evolution-fish.html | title=Odd Fish Find Contradicts Intelligent-Design Argument | publisher=[[National Geographic Society|National Geographic]] |date= July 9, 2008 | first= | last= | accessdate =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|journal=Nature|volume=454|number=7201|date=2008-07-10|pages=209–212|doi= 10.1038/nature07108|pmid=18615083|issue=7201}}</ref>
|-
| [[File:VMNHMegalodon megalodonNT.jpg|140px]]
| ''[[Megalodon]]''
|
| {{ external media
''[[MegalodonCarcharodon megalodon]]'' isè anuna extinctspecie speciesestinta ofdi shark[[squalo]] thatche livedvisse abouttra i 28 toe 1.,5&nbsp;Ma. Itmilioni lookeddi muchanni likefa. aFisicamente stockysimile versional ofSembrava themolto simile al [[greatgrande whitesqualo sharkbianco]], butera wastuttavia muchdecisamente largerpiù withgrande, fossilcon lengthsuna reachinglunghezza stimata su ritrovamenti fossili che raggiunge i {{convert|20.,3|m|ft}}. metri <ref name="GWB" /> Found in all oceans<ref name="AN">{{Cite journal|last=Pimiento|first=Catalina|coauthors=Dana J. Ehret, Bruce J. MacFadden, and Gordon Hubbell|title=Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama|journal=PLoS ONE|volume=5|issue=5|pages=e10552|publisher=PLoS.org|___location=Panama|date=May 10, 2010|pmid=20479893|url=http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010552|pmc=2866656|doi=10.1371/journal.pone.0010552|accessdate=12 May 2010|editor1-last=Stepanova|editor1-first=Anna|bibcode = 2010PLoSO...510552P }}, anche se si ipotizza che superasse queste dimensioni </ref> it was one of the largest and most powerful predators in vertebrate history,<ref name="GWB">{{cite journal|last=Wroe|first=S.|coauthors= Huber, D. R. ; Lowry, M. ; McHenry, C. ; Moreno, K. ; Clausen, P. ; Ferrara, T. L. ; Cunningham, E. ; Dean, M. N. ; Summers, A. P.|title=Three-dimensional computer analysis of white shark jaw mechanics: how hard can a great white bite?|url=http://www.bio-nica.info/Biblioteca/Wroe2008GreatWhiteSharkBiteForce.pdf|journal=Journal of Zoology|volume=276|issue=4|pages=336–342|year= 2008|doi=10.1111/j.1469-7998.2008.00494.x}}</ref>, andIl probably''Megalodon'' hadviveva ain profoundtutti impactgli onoceani [[marineed life]].era uno dei più grandi e potenti predatori nella storia dei vertebrati che ha avuto un profondo impatto sulla vita marina<ref name="LV">{{Cite journal|doi=10.1038/nature09067|last=Lambert|first=Olivier|coauthors=Giovanni Bianucci, Klaas Post, Christian de Muizon, Rodolfo Salas-Gismondi, Mario Urbina and Jelle Reumer|title=The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru|journal=Nature|volume=466|issue=7302|pages=105–108|___location=Peru|date=1 July 2010|url=http://www.nature.com/nature/journal/v466/n7302/full/nature09067.html|pmid=20596020|bibcode = 2010Natur.466..105L }}</ref>
| align =
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| video1 = [http://www.youtube.com/watch?v=_9LAWve5Xq4 Megalodon battle] ''History Channel''
| video2 = [http://www.youtube.com/watch?v=Spo8vkrJFRo The Nightmarish Megalodon] ''Discovery''}}
 
[[Megalodon]] is an extinct species of shark that lived about 28 to 1.5&nbsp;Ma. It looked much like a stocky version of the [[great white shark]], but was much larger with fossil lengths reaching {{convert|20.3|m|ft}}.<ref name="GWB" /> Found in all oceans<ref name="AN">{{Cite journal|last=Pimiento|first=Catalina|coauthors=Dana J. Ehret, Bruce J. MacFadden, and Gordon Hubbell|title=Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama|journal=PLoS ONE|volume=5|issue=5|pages=e10552|publisher=PLoS.org|___location=Panama|date=May 10, 2010|pmid=20479893|url=http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010552|pmc=2866656|doi=10.1371/journal.pone.0010552|accessdate=12 May 2010|editor1-last=Stepanova|editor1-first=Anna|bibcode = 2010PLoSO...510552P }}</ref> it was one of the largest and most powerful predators in vertebrate history,<ref name="GWB">{{cite journal|last=Wroe|first=S.|coauthors= Huber, D. R. ; Lowry, M. ; McHenry, C. ; Moreno, K. ; Clausen, P. ; Ferrara, T. L. ; Cunningham, E. ; Dean, M. N. ; Summers, A. P.|title=Three-dimensional computer analysis of white shark jaw mechanics: how hard can a great white bite?|url=http://www.bio-nica.info/Biblioteca/Wroe2008GreatWhiteSharkBiteForce.pdf|journal=Journal of Zoology|volume=276|issue=4|pages=336–342|year= 2008|doi=10.1111/j.1469-7998.2008.00494.x}}</ref> and probably had a profound impact on [[marine life]].<ref name="LV">{{Cite journal|doi=10.1038/nature09067|last=Lambert|first=Olivier|coauthors=Giovanni Bianucci, Klaas Post, Christian de Muizon, Rodolfo Salas-Gismondi, Mario Urbina and Jelle Reumer|title=The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru|journal=Nature|volume=466|issue=7302|pages=105–108|___location=Peru|date=1 July 2010|url=http://www.nature.com/nature/journal/v466/n7302/full/nature09067.html|pmid=20596020|bibcode = 2010Natur.466..105L }}</ref>
|}