Editing Artiodactyl (section)

==Evolutionary history==
{{See also|Evolution of cetaceans}}
The oldest fossils of even-toed ungulates date back to the early [[Eocene]] (about 53 million years ago). Since these findings almost simultaneously appeared in [[Europe]], [[Asia]], and [[North America]], it is very difficult to accurately determine the origin of artiodactyls. The earliest artiodactyls did not significantly affect ungulate locomotor disparity in North America, which suggests that artiodactyls did not outcompete more basal ungulates through [[Competitive exclusion principle|competitive exclusion]].<ref>{{Cite journal |last=Gould |first=François D. H. |date=10 November 2016 |title=Testing the Role of Cursorial Specializations as Adaptive Key Innovations in Paleocene-Eocene Ungulates of North America |url=https://link.springer.com/article/10.1007/s10914-016-9359-4 |journal=[[Journal of Mammalian Evolution]] |language=en |volume=24 |issue=4 |pages=453–463 |doi=10.1007/s10914-016-9359-4 |issn=1064-7554 |access-date=9 April 2025 |via=Springer Nature Link}}</ref> The oldest artidactyl fossils are classified as belonging to the family [[Diacodexeidae]];<ref name=Orliac2012>{{cite journal |last1= Orliac |first1= M.J.|last2= Benoit |first2= J. |last3= O'Leary |first3= M.A. |date= November 2012 |title= The inner ear of ''Diacodexis'', the oldest artiodactyl mammal |journal= Journal of Anatomy |volume= 21 |issue= 5 |pages= 417–426 |doi= 10.1111/j.1469-7580.2012.01562.x|pmid= 22938073|pmc= 3482349|s2cid= 2010691}}</ref><ref name=Prothero2007/><ref name=Boivin2018>{{cite journal |last1= Boivin |first1= M. |last2= Orliac |first2= M.J. |display-authors= etal |date= September 2018 |title= New material of ''Diacodexis'' (Mammalia, Artiodactyla) from the early Eocene of Southern Europe |journal= Geobios |volume= 51 |issue= 4 |pages= 285–306 |doi= 10.1016/j.geobios.2018.06.003 |bibcode= 2018Geobi..51..285B |s2cid= 134967454 |url= https://hal.archives-ouvertes.fr/hal-03052875/file/Boivin_etal_Geobios_2018.pdf |access-date= 16 October 2023 |archive-date= 2 March 2022 |archive-url= https://web.archive.org/web/20220302025914/https://hal.archives-ouvertes.fr/hal-03052875/file/Boivin_etal_Geobios_2018.pdf |url-status= live }}</ref> their best-known and best-preserved member is ''[[Diacodexis]]''.<ref name=Prothero2007>{{Cite book |first1=Jessica M. |last1=Theodor |title=Evolution of Artiodactyls |first2=Jörg |last2=Erfurt |last3=Grégoire Métais |date=2007-10-23 |publisher=Johns Hopkins University |isbn=9780801887352 |editor-first=Donald R. |editor-last=Prothero |pages=32–58 |chapter=The earliest artiodactyls: Diacodexeidae, Dichobunidae, Homacodontidae, Leptochoeridae and Raoellidae |editor-first2=Scott E. |editor-last2=Foss |chapter-url=https://books.google.com/books?id=qO8H_alEofAC&pg=PA32}}</ref> These were small animals, some as small as a [[hare]], with a slim build, lanky legs, and a long tail. Their hind legs were much longer than their front legs. The [[Ypresian|early]] to middle Eocene saw the emergence of the ancestors of most of today's mammals.<ref name="spaulding2009" />

[[File:entelodon Sp Illustration.jpg|thumb|[[Entelodont]]s were stocky animals with a large head, and were characterized by bony bumps on the lower jaw.|alt=Two large boar-like creatures graze.]]

Two formerly widespread, but now extinct, families of even-toed ungulates were [[Entelodont]]idae and [[Anthracotheriidae]]. Entelodonts existed from the middle Eocene to the [[early Miocene]] in [[Eurasia]] and North America. They had a stocky body with short legs and a massive head, which was characterized by two humps on the lower jaw bone. Anthracotheres had a large, porcine ([[pig]]-like) build, with short legs and an elongated [[Snout|muzzle]]. This group appeared in the middle Eocene up until the [[Pliocene]], and spread throughout Eurasia, Africa, and North America. Anthracotheres are thought to be the ancestors of hippos, and, likewise, probably led a similar aquatic lifestyle. Hippopotamuses appeared in the [[late Miocene]] and occupied Africa and Asia—they never got to the Americas.<ref name="spaulding2009" />

The camels ([[Tylopoda]]) were, during large parts of the [[Cenozoic]], limited to North America; early forms like [[Cainotheriidae]] occupied Europe. Among the North American camels were groups like the stocky, short-legged [[Merycoidodontidae]]. They first appeared in the late Eocene and developed a great diversity of species in North America. Only in the late Miocene or early Pliocene did they migrate from North America into Eurasia. The [[List of mammals of North America#Camelidae|North American varieties]] became extinct around 10,000 years ago. {{citation needed|date=December 2024}}

[[Suina]] (including [[pig]]s) have been around since the Eocene. In the late Eocene or the [[Oligocene]], two families stayed in Eurasia and Africa; the [[peccaries]], which became extinct in the [[Old World]], exist today only in the [[Americas]]. {{citation needed|date=December 2024}}

[[File:MEPAN Sivatherium.jpg|thumb|''[[Sivatherium]]'' was a relative of giraffes with deer-like forehead [[ossicones]].|alt=A deer-like animal wanders through a clearing.]]

South America was [[Great American Interchange|settled by terrestrial even-toed ungulates]] only in the Pliocene, after the [[land bridge]] at the [[Isthmus of Panama]] formed some three million years ago. With only the peccaries, lamoids (or [[llama]]s), and various species of [[Capreolinae|capreoline deer]], South America has [[List of mammals of South America#Order: Artiodactyla (even-toed ungulates and cetaceans)|comparatively fewer artiodactyl families]] than other continents, except Australia, which has no (terrestrial) native species.{{citation needed|date=December 2024}}

[[File:Anoplotherium commune quadrupedal.png|thumb|right|''[[Anoplotherium]]'' was the first fossil artiodactyl genus to be named, with a history dating back to 1804. It lived in Europe as part of the endemic family [[Anoplotheriidae]] during the late Eocene-earliest Oligocene.]]