Editing Endotherm (section)

==Origin==
Endothermy was thought to have originated towards the end of the [[Permian]] Period'''''<ref>{{cite journal | vauthors = Rey K, Amiot R, Fourel F, Abdala F, Fluteau F, Jalil NE, Liu J, Rubidge BS, Smith RM, Steyer JS, Viglietti PA, Wang X, Lécuyer C | display-authors = 6 | title = Oxygen isotopes suggest elevated thermometabolism within multiple Permo-Triassic therapsid clades | journal = eLife | volume = 6 | date = July 2017 | pmid = 28716184 | pmc = 5515572 | doi = 10.7554/eLife.28589 | doi-access = free }}</ref>'''''. One recent study claimed the origin of endothermy within [[Synapsida]] (the mammalian lineage) was among [[Mammaliamorpha]], a node calibrated during the [[Late Triassic]] period, about 233 million years ago.'''''<ref>{{cite journal | vauthors = Araújo R, David R, Benoit J, Lungmus JK, Stoessel A, Barrett PM, Maisano JA, Ekdale E, Orliac M, Luo ZX, Martinelli AG, Hoffman EA, Sidor CA, Martins RM, Spoor F, Angielczyk KD | display-authors = 6 | title = Inner ear biomechanics reveals a Late Triassic origin for mammalian endothermy | journal = [[Nature (journal)|Nature]] | volume = 607 | issue = 7920 | pages = 726–731 | date = July 2022 | pmid = 35859179 | doi = 10.1038/s41586-022-04963-z | s2cid = 236245230 }}</ref>''''' Another study instead argued that endothermy only appeared later, during the [[Middle Jurassic]], among crown-group mammals.<ref>{{cite journal |last1=Newham |first1=Elis |last2=Gill |first2=Pamela G. |last3=Corfe |first3=Ian J. |date=16 February 2022 |title=New tools suggest a middle Jurassic origin for mammalian endothermy |journal=[[BioEssays]] |volume=44 |issue=4 |pages=e2100060 |doi=10.1002/bies.202100060 |pmid=35170781 |s2cid=247599805 |doi-access=free }}</ref>

Evidence for endothermy has been found in basal synapsids ("[[pelycosaur]]s"), [[Pareiasaur|pareiasaurs]], [[Ichthyosaur|ichthyosaurs]], [[Plesiosaur|plesiosaurs]], [[Mosasaur|mosasaurs]], and basal [[Archosauromorpha|archosauromorphs]].<ref name=":1">{{cite journal | vauthors = Grigg G, Nowack J, Bicudo JE, Bal NC, Woodward HN, Seymour RS | title = Whole-body endothermy: ancient, homologous and widespread among the ancestors of mammals, birds and crocodylians | journal = Biological Reviews of the Cambridge Philosophical Society | volume = 97 | issue = 2 | pages = 766–801 | date = April 2022 | pmid = 34894040 | pmc = 9300183 | doi = 10.1111/brv.12822 }}</ref><ref>{{cite journal | vauthors = Legendre LJ, Guénard G, Botha-Brink J, Cubo J | title = Palaeohistological Evidence for Ancestral High Metabolic Rate in Archosaurs | journal = Systematic Biology | volume = 65 | issue = 6 | pages = 989–996 | date = November 2016 | pmid = 27073251 | doi = 10.1093/sysbio/syw033 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Benton MJ |date= December 2021 |title=The origin of endothermy in synapsids and archosaurs and arms races in the Triassic |journal=Gondwana Research |language=en |volume=100 |pages=261–289 |doi=10.1016/j.gr.2020.08.003|s2cid= 222247711 |doi-access=free }}</ref> Even the earliest amniotes might have been endotherms.<ref name=":1" />