Editing Sea turtle (section)

==Taxonomy and evolution==
Sea turtles, along with other turtles and tortoises, are part of the order [[Turtle|Testudines]]. All species except the leatherback sea turtle are in the family [[Cheloniidae]]. The superfamily name Chelonioidea and family name Cheloniidae are based on the [[Ancient Greek]] word for tortoise: {{lang|grc|χελώνη}} (''{{transliteration|grc|khelōnē}}'').<ref>{{LSJ|xelw/nh|χελώνη|ref}}</ref> The leatherback sea turtle is the only extant member of the family [[Dermochelyidae]].

Fossil evidence of marine turtles goes back to the [[Late Jurassic]] (150 million years ago) with genera such as ''[[Plesiochelys]]'', from Europe. In Africa, the first marine turtle is ''[[Angolachelys]]'', from the Turonian of Angola.<ref>{{cite journal|last1=Mateus|title=The oldest African eucryptodiran turtle from the Cretaceous of Angola|journal=Acta Palaeontologica Polonica|date=2009|volume=54|issue=4|pages=581–588|display-authors=etal|doi=10.4202/app.2008.0063|s2cid=55919209|url=http://doc.rero.ch/record/203067/files/PAL_E3914.pdf|doi-access=free}}</ref> A lineage of unrelated marine testudines, the [[pleurodire]] (side-necked) [[bothremydids]], also survived well into the Cenozoic. Other pleurodires are also thought to have lived at sea, such as ''[[Araripemys]]''<ref>Kischlat, E.-E & Campos, D. de 1990. Some osteological aspects of Araripemys barretoi Price, 1973 (Chelonii, Pleurodira, Araripemydidae). In Atas do I Simpósio sobre a Bacia do Araripe e Bacias Interiores do Nordeste Crato, 14 a 16 de junho de 1990, pp. 387–395.</ref> and extinct [[Pelomedusidae|pelomedusid]]s.<ref>{{Cite journal |last1=Ferreira |first1=Gabriel S. |last2=Rincón |first2=Ascanio D. |last3=Solórzano |first3=Andrés |last4=Langer |first4=Max C. |date=June 30, 2015 |title=The last marine pelomedusoids (Testudines: Pleurodira): a new species of Bairdemys and the paleoecology of Stereogenyina |journal=PeerJ |volume=3 |pages=e1063 |doi=10.7717/peerj.1063 |pmc=4493680 |pmid=26157628 |doi-access=free}}</ref> Modern sea turtles are not descended from more than one of the groups of sea-going turtles that have existed in the past; they instead constitute a single radiation that became distinct from all other turtles at least 110 million years ago.<ref>{{cite web |title=Meet the Turtles {{!}} SWOT |url=http://www.seaturtlestatus.org/learn/meet-the-turtles |access-date=2017-09-20 |website=www.seaturtlestatus.org}}</ref><ref>{{Cite journal |title=An Introduction to Sea Turtles |url=http://seaturtlestatus.org/sites/swot/files/061810_SWOT1_p04_IntroSeaTurtles.pdf |journal=SWOT}}</ref><ref>{{cite journal |last1=Kear |first1=Benjamin P |date=22 March 2006 |title=A primitive protostegid from Australia and early sea turtle evolution |journal=Biology Letters |volume=2 |issue=1 |pages=116–119 |doi=10.1098/rsbl.2005.0406 |pmc=1617175 |pmid=17148342}}</ref> Their closest extant relatives are in fact the [[Chelydridae|snapping turtles]] (Chelydridae), [[Kinosternidae|musk turtles]] (Kinosternidae), and [[hickatee]] ([[Dermatemydidae|Dermatemyidae]]) of the Americas, which alongside the sea turtles constitute the clade [[Americhelydia]].<ref>{{Cite journal |last1=Gable |first1=Simone M. |last2=Byars |first2=Michael I. |last3=Literman |first3=Robert |last4=Tollis |first4=Marc |date=2021-10-16 |title=A Genomic Perspective on the Evolutionary Diversification of Turtles |url=http://dx.doi.org/10.1101/2021.10.14.464421 |journal=bioRxiv|access-date=2022-11-17 |doi=10.1101/2021.10.14.464421 |s2cid=239029388 }}</ref> 

The oldest possible representative of the lineage ([[Panchelonioidea]]) leading to modern sea turtles was possibly ''[[Desmatochelys padillai]]'' from the Early Cretaceous. ''Desmatochelys'' was a [[Protostegidae|protostegid]], a lineage that would later give rise to some very large species but went extinct at the end of the Cretaceous. Presently thought to be outside the [[crown group]] that contains modern sea turtles (Chelonioidea), the exact relationships of protostegids to modern sea turtles are still debated due to their primitive morphology; they may be the [[sister group]] to the Chelonoidea, or an unrelated turtle lineage that [[Convergent evolution|convergently evolved]] similar adaptations.<ref>{{Cite thesis |title=The Evolution of Sea Turtles |url=https://digital.library.adelaide.edu.au/dspace/handle/2440/134280 |date=2021 |degree=Thesis |language=en |first=Ray |last=Chatterji}}</ref><ref>{{Cite journal |last=Goulart |first=Isabella Vasconcellos |date=2021-01-13 |title=Evaluation of Panchelonioidea (Testudines: Cryptodira) evolution based on phylogenetic morphometrics |url=https://locus.ufv.br//handle/123456789/27977 |journal=Locus}}</ref> The earliest "true" sea turtle that is known from fossils is ''[[Nichollsemys]]'' from the Early Cretaceous ([[Albian]]) of [[Canada]]. In 2022, the giant fossil species ''[[Leviathanochelys]]'' was described from [[Spain]]. This species inhabited the oceans covering Europe in the Late Cretaceous and rivaled the concurrent giant protostegids such as ''[[Archelon]]'' and ''[[Protostega]]'' as one of the largest turtles to ever exist. Unlike the protostegids, which have an uncertain relationship to modern sea turtles, ''Leviathanochelys'' is thought to be a true sea turtle of the superfamily Chelonioidea.<ref name=":19">{{Cite journal |last1=Castillo-Visa |first1=Oscar |last2=Luján |first2=Àngel H. |last3=Galobart |first3=Àngel |last4=Sellés |first4=Albert |date=2022-11-17 |title=A gigantic bizarre marine turtle (Testudines: Chelonioidea) from the Middle Campanian (Late Cretaceous) of South-western Europe |journal=Scientific Reports |language=en |volume=12 |issue=1 |pages=18322 |doi=10.1038/s41598-022-22619-w |pmid=36396968 |pmc=9671902 |bibcode=2022NatSR..1218322C |s2cid=253584457 |issn=2045-2322}}</ref>

Sea turtles' limbs and brains have evolved to adapt to their diets. Their limbs originally evolved for locomotion, but more recently evolved to aid them in feeding. They use their limbs to hold, swipe, and forage their food. This helps them eat more efficiently.<ref>{{cite web|url=https://www.newswise.com/articles/sea-turtles-use-flippers-to-manipulate-food |title=Sea Turtles Use Flippers to Manipulate Food |publisher=Newswise.com |access-date=2018-09-16}}</ref><ref>{{cite web | url=https://www.sciencedaily.com/releases/2018/03/180328083421.htm | title=Sea turtles use flippers to manipulate food}}</ref>

=== Cladogram ===
Below is a [[cladogram]] showing the phylogenetic relationships of living and extinct sea turtles in the Chelonioidea based on Evers et al. (2019):<ref>{{Cite journal|last1=Evers|first1=Serjoscha W.|last2=Barrett|first2=Paul M.|last3=Benson|first3=Roger B. J.|date=2019-05-01|title=Anatomy of ''Rhinochelys pulchriceps'' (Protostegidae) and marine adaptation during the early evolution of chelonioids|journal=PeerJ|volume=7|pages=e6811|doi=10.7717/peerj.6811|issn=2167-8359|pmc=6500378|pmid=31106054 |doi-access=free }}</ref>

{| style="margin:auto;"
|-
|
{{cladogram|title=Phylogenetic relations of living and extinct chelonioid species
|align=left
|clades={{Clade|style=font-size:85%;line-height:85%;width:500px
|label1=[[Panchelonioidea]]
|1={{Clade
   |1=†''[[Toxochelys]]''
   |2={{Clade
      |1=†[[Protostegidae]] [[File:Protostega gigas.jpg|70 px]]
      |label2=[[Chelonioidea]]
      |2={{Clade
         |1=†''[[Corsochelys]]''
         |2=[[Dermochelyidae]] [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Dermochelys coriacea).jpg|70 px]]
         |label3=[[Pancheloniidae]]
         |3={{Clade
            |1=†''[[Nichollsemys]]''
            |2={{Clade
               |1=†''[[Allopleuron]]''
               |2={{Clade
                  |1=[[Cheloniidae]] [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Chelonia mydas).jpg|70 px]]
                  |2={{Clade
                     |1=†''[[Argillochelys]]''
                     |2=†''[[Procolpochelys]]''
                     |3={{Clade
                        |1=†''[[Eochelone]]''
                        |2=†''[[Puppigerus]]'' }}
                     |4={{Clade
                        |1=†''[[Ctenochelys]]''
                        |2=†''[[Peritresius]]''
                        |3=†''[[Cabindachelys]]'' }}
}} }} }} }} }} }} }} }} }}
|}
An alternate phylogeny was proposed by Castillo-Visa ''et al.'' (2022):<ref name=":19" />

{{clade|{{clade
|1=†[[Toxochelyidae]]
|2={{clade
|1=†[[Protostegidae]]
|2=†''[[Corsochelys]]''
|label3='''Chelonioidea'''
|3= {{clade
 |label1=[[Dermochelyidae]]
 |1={{clade
  |1=†''[[Eosphargis]]''
  |2=''[[Dermochelys]]''
}}
 |2={{clade
  |1=†''[[Nichollsemys]]''
  |2={{clade
   |1={{clade
    |1=†''[[Leviathanochelys]]''
    |2=†''[[Allopleuron]]''
}}
   |2={{clade
    |1=†''[[Procolpochelys]]''
    |2={{clade
     |1=†''[[Argillochelys]]''
     |2={{clade
      |1=†''[[Eochelone]]''
      |2=†''[[Puppigerus]]''
}}
     |label3=[[Ctenochelyidae]]
     |3={{clade
      |1=†''[[Cabindachelys]]''
      |2=†''[[Ctenochelys]]''
      |3=†''[[Peritresius]]''
}}
     |label4=[[Cheloniidae]]
     |4={{clade
      |1=''[[Natator]]''
      |2=''[[Eretmochelys]]''
      |3=''[[Chelonia]]''
      |4={{clade
       |1=''[[Lepidochelys kempii]]''
       |2={{clade
        |1=''[[Caretta]]''
        |2=''[[Lepidochelys olivacea]]''
}}}}}}}}}}}}}}}}}}}}|style=font-size:85%;line-height:85%|label1=[[Panchelonioidea]]}}