Editing Proboscidea

{{short description|Order of  mammals including elephants}}
{{for|the plant genus|Proboscidea (plant)}}
{{Use dmy dates|date=August 2020}}
{{Automatic taxobox
| fossil_range = Middle [[Paleocene]]-[[Holocene]] {{Fossil range|60.0|0}}
| image = Elephant Diversity.jpg
| image_caption = Proboscidean diversity: [[Indian elephant]], ''[[Elephas maximus indicus]]'', [[African bush elephant]], ''[[Loxodonta africana]]'' and [[African forest elephant]], ''[[Loxodonta cyclotis]]''
| image2 = Moeritherium sp.jpg
| image2_caption = Skeleton of ''[[Moeritherium]]''
| taxon = Proboscidea
| authority = [[Johann Karl Wilhelm Illiger|Illiger]], 1811
| subdivision_ranks = Subclades
| subdivision = 
*†''[[Arcanotherium]]''
*†''[[Barytherium]]''
*†''[[Daouitherium]]''
*†''[[Eritherium]]''
*†''[[Moeritherium]]''
*†''[[Numidotherium]]''
*†''[[Omanitherium]]''
*†''[[Phosphatherium]]''
*†''[[Saloumia]]''
*†[[Deinotheriidae]]
*[[Elephantiformes]]
}}

'''Proboscidea''' ({{IPAc-en|ˌ|p|r|oʊ|b|ə|ˈ|s|ɪ|d|i|ə}};  {{etymology|la|{{wikt-lang|la|proboscis}}|}}, {{etymology|grc|''{{wikt-lang|grc|προβοσκίς}}'' ({{grc-transl|προβοσκίς}})|elephant's trunk}}) is a [[taxonomy (biology)|taxonomic]] [[order (biology)|order]] of [[afrotheria]]n mammals containing one living [[family (biology)|family]] ([[Elephantidae]]) and several extinct families. First described by [[Johann Karl Wilhelm Illiger|J. Illiger]] in 1811, it encompasses the [[elephant]]s and their close relatives.<ref>{{cite book |last=Illiger|first=Johann Karl Wilhelm |title=Prodromus Systematis Mammalium et Avium: Additis Terminis Zoographicis Utriusque Classis, Eorumque Versione Germanica |date=1811 |publisher=Berolini: Sumptibus C. Salfeld |page=62 |url=https://archive.org/details/caroliilligerida00illi}}</ref> Three living [[species]] of [[elephant]] are currently recognised: the [[African bush elephant]], the [[African forest elephant]], and the [[Asian elephant]]. 

Extinct members of Proboscidea include the [[Deinotheriidae|deinotheres]], [[mastodon]]s, [[gomphothere]]s and [[stegodon]]ts. The family Elephantidae also contains several extinct groups, including [[mammoth]]s and ''[[Palaeoloxodon]]''. Proboscideans include some of the largest known land mammals, with the elephant ''[[Palaeoloxodon namadicus]]'' and mastodon ''[["Mammut" borsoni]]'' suggested to have body masses surpassing {{Convert|16|t|lb}}, rivalling or exceeding [[Paraceratheriidae|paraceratheres]] (the otherwise largest known land mammals) in size.<ref name="Larramendi, A. 2015" /> The largest extant proboscidean is the African bush elephant, with a world record of size of {{cvt|4|m|ft|1}} at the shoulder and {{cvt|10.4|MT|ST|1}}.<ref name="Larramendi, A. 2015" /> In addition to their enormous size, later proboscideans are distinguished by tusks and long, muscular trunks, which were less developed or absent in early proboscideans.

==Evolution==
Over 180 extinct members of Proboscidea have been described.<ref>{{cite book |last1=Kingdon |first1=Jonathan |url=https://books.google.com/books?id=B_07noCPc4kC |title=Mammals of Africa |date=2013 |publisher=Bloomsbury |isbn=9781408189962 |page=173 |access-date=6 June 2020 |archive-url=https://web.archive.org/web/20230321084755/https://books.google.com/books?id=B_07noCPc4kC |archive-date=21 March 2023 |url-status=live}}</ref>  The earliest members of Proboscidea like ''[[Eritherium]]'' are known from the [[Paleocene]] of Africa, around 60 million years ago, the earliest proboscideans were much smaller than living elephants, with ''Eritherium'' having a body mass of around {{Convert|3-8|kg}}.<ref name="Gheerbrant2">{{cite journal |author=Gheerbrant, E. |year=2009 |title=Paleocene emergence of elephant relatives and the rapid radiation of African ungulates |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=106 |issue=26 |pages=10717–10721 |bibcode=2009PNAS..10610717G |doi=10.1073/pnas.0900251106 |pmc=2705600 |pmid=19549873 |doi-access=free}}</ref> By the late [[Eocene]], some members of Proboscidea like ''[[Barytherium]]'' had reached considerable size, with an estimated mass of around 2 tonnes,<ref name="Larramendi, A. 2015" /> while others like ''[[Moeritherium]]'' are suggested to have been semi-aquatic.<ref>{{Cite journal |last1=Liu |first1=Alexander G. S. C. |last2=Seiffert |first2=Erik R. |last3=Simons |first3=Elwyn L. |date=2008-04-15 |title=Stable isotope evidence for an amphibious phase in early proboscidean evolution |journal=Proceedings of the National Academy of Sciences |language=en |volume=105 |issue=15 |pages=5786–5791 |bibcode=2008PNAS..105.5786L |doi=10.1073/pnas.0800884105 |issn=0027-8424 |pmc=2311368 |pmid=18413605 |doi-access=free}}</ref>

A major event in proboscidean evolution was the collision of Afro-Arabia with Eurasia, during the Early [[Miocene]], around 18-19 million years ago allowing proboscideans to disperse from their African homeland across Eurasia, and later, around 16-15 million years ago into North America across the Bering Land Bridge. Proboscidean groups prominent during the Miocene include the [[deinothere]]s, along with the more advanced [[Elephantimorpha|elephantimorphs]], including [[Mammutidae|mammutids]] (mastodons), [[gomphothere]]s, [[Amebelodontidae|amebelodontids]] (which includes the "shovel tuskers" like ''[[Platybelodon]]''), [[Choerolophodontidae|choerolophodontids]] and [[Stegodontidae|stegodontids]].<ref name=":2">{{Cite journal |last1=Cantalapiedra |first1=Juan L. |last2=Sanisidro |first2=Óscar |last3=Zhang |first3=Hanwen |last4=Alberdi |first4=María T. |last5=Prado |first5=José L. |last6=Blanco |first6=Fernando |last7=Saarinen |first7=Juha |date=2021-07-01 |title=The rise and fall of proboscidean ecological diversity |url=https://www.nature.com/articles/s41559-021-01498-w |journal=Nature Ecology & Evolution |language=en |volume=5 |issue=9 |pages=1266–1272 |doi=10.1038/s41559-021-01498-w |issn=2397-334X |pmid=34211141 |bibcode=2021NatEE...5.1266C |s2cid=235712060|hdl=10261/249360 |hdl-access=free }}</ref> Around 10 million years ago, the earliest members of the family [[Elephantidae]] emerged in Africa, having originated from gomphotheres.<ref>H. Saegusa, H. Nakaya, Y. Kunimatsu, M. Nakatsukasa, H. Tsujikawa, Y. Sawada, M. Saneyoshi, T. Sakai [https://apo.ansto.gov.au/dspace/bitstream/10238/9340/2/icmr_volume_low.pdf#page=188 Earliest elephantid remains from the late Miocene locality, Nakali, Kenya] Scientific Annals, School of Geology, Aristotle University of Thessaloniki, Greece VIth International Conference on Mammoths and Their Relatives, vol. 102, Grevena -Siatista, special volume (2014), p. 175</ref> The Late Miocene saw major climatic changes, which resulted in the decline and extinction of many proboscidean groups such as amebelodontids and choerolophodontids.<ref name=":2" /> The earliest members of modern genera of Elephantidae appeared during the latest Miocene-early Pliocene around 6-5 million years ago. The elephantid genera ''[[Elephas]]'' (which includes the living Asian elephant) and ''[[Mammuthus]]'' (mammoths) migrated out of Africa during the late Pliocene, around 3.6 to 3.2 million years ago.<ref>{{Cite journal |last1=Iannucci |first1=Alessio |last2=Sardella |first2=Raffaele |date=2023-02-28 |title=What Does the "Elephant-Equus" Event Mean Today? Reflections on Mammal Dispersal Events around the Pliocene-Pleistocene Boundary and the Flexible Ambiguity of Biochronology |journal=Quaternary |language=en |volume=6 |issue=1 |pages=16 |doi=10.3390/quat6010016 |issn=2571-550X |doi-access=free|hdl=11573/1680082 |hdl-access=free }}</ref>

Over the course of the [[Early Pleistocene]], all non-elephantid probobscideans outside of the Americas became extinct (including mammutids, gomphotheres and deinotheres), with the exception of ''[[Stegodon]]''.<ref name=":2" />  Gomphotheres dispersed into South America during this era as part of the [[Great American interchange]],<ref name="Mothé et al 2016 (In Press)">{{cite journal |last1=Mothé |first1=Dimila |last2=dos Santos Avilla |first2=Leonardo |last3=Asevedo |first3=Lidiane |last4=Borges-Silva |first4=Leon |last5=Rosas |first5=Mariane |last6=Labarca-Encina |first6=Rafael |last7=Souberlich |first7=Ricardo |last8=Soibelzon |first8=Esteban |last9=Roman-Carrion |first9=José Luis |last10=Ríos |first10=Sergio D. |last11=Rincon |first11=Ascanio D. |last12=Cardoso de Oliveira |first12=Gina |last13=Pereira Lopes |first13=Renato |date=30 September 2016 |title=Sixty years after 'The mastodonts of Brazil': The state of the art of South American proboscideans (Proboscidea, Gomphotheriidae) |url=http://bibdigital.epn.edu.ec/bitstream/15000/17075/1/Moth%c3%a9%20et%20al.%2c%202016%20-%20Sixty%20years%20proboscideans.pdf |journal=Quaternary International |volume=443 |pages=52–64 |bibcode=2017QuInt.443...52M |doi=10.1016/j.quaint.2016.08.028}}</ref> and mammoths migrating into North America around 1.5 million years ago.<ref>{{Cite journal |last1=Lister |first1=A. M. |last2=Sher |first2=A. V. |date=2015-11-13 |title=Evolution and dispersal of mammoths across the Northern Hemisphere |journal=Science |language=en |volume=350 |issue=6262 |pages=805–809 |bibcode=2015Sci...350..805L |doi=10.1126/science.aac5660 |issn=0036-8075 |pmid=26564853 |s2cid=206639522}}</ref> At the end of the Early Pleistocene, around 800,000 years ago the elephantid genus ''[[Palaeoloxodon]]'' dispersed outside of Africa, becoming widely distributed in Eurasia.<ref name=":0">{{Citation |last=Lister |first=Adrian M. |title=Ecological Interactions of Elephantids in Pleistocene Eurasia |date=2004 |url=https://www.researchgate.net/publication/264788794 |work=Human Paleoecology in the Levantine Corridor |pages=53–60 |access-date=2020-04-14 |publisher=Oxbow Books |isbn=978-1-78570-965-4}}</ref> By the beginning of the [[Late Pleistocene]], proboscideans were represented by around 23 species. Proboscideans underwent a dramatic decline during the Late Pleistocene as part of the [[Late Pleistocene extinctions|Late Pleistocene megafauna extinctions]], with all remaining non-elephantid proboscideans (including ''Stegodon'', [[mastodon]]s, and the American gomphotheres ''[[Cuvieronius]]'' and ''[[Notiomastodon]]'') and ''[[Palaeoloxodon]]'' becoming extinct, with mammoths only surviving in [[Relict (biology)|relict]] populations on islands around the [[Bering Strait]] into the Holocene, with their latest survival being on [[Wrangel Island]] around 4,000 years ago.<ref name=":2" /><ref>{{Cite journal |last1=Rogers |first1=Rebekah L. |last2=Slatkin |first2=Montgomery |date=2017-03-02 |editor-last=Barsh |editor-first=Gregory S. |title=Excess of genomic defects in a woolly mammoth on Wrangel island |journal=PLOS Genetics |language=en |volume=13 |issue=3 |pages=e1006601 |doi=10.1371/journal.pgen.1006601 |issn=1553-7404 |pmc=5333797 |pmid=28253255 |doi-access=free }}</ref>

The following cladogram is based on endocasts.<ref>{{Citation |last1=Benoit |first1=Julien |title=Paleoneurology of the Proboscidea (Mammalia, Afrotheria): Insights from Their Brain Endocast and Labyrinth |date=2023 |url=https://link.springer.com/10.1007/978-3-031-13983-3_15 |work=Paleoneurology of Amniotes |pages=579–644 |editor-last=Dozo |editor-first=María Teresa |access-date=2023-05-22 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-13983-3_15 |isbn=978-3-031-13982-6 |last2=Lyras |first2=George A. |last3=Schmitt |first3=Arnaud |last4=Nxumalo |first4=Mpilo |last5=Tabuce |first5=Rodolphe |last6=Obada |first6=Teodor |last7=Mararsecul |first7=Vladislav |last8=Manger |first8=Paul |editor2-last=Paulina-Carabajal |editor2-first=Ariana |editor3-last=Macrini |editor3-first=Thomas E. |editor4-last=Walsh |editor4-first=Stig|url-access=subscription }}</ref>

{{clade
|grouplabel1={{clade labels |label1="plesielephantiforms" |top1=9%
                            |label2="mastodonts"          |top2=46%
                            }}
|label1=[[Proboscidea]]
|1={{clade
   |1=''[[Phosphatherium esculliei]]''  [[File:Phosphatherium - head restoration.tif|50px]]  |bar1=green
   |2={{clade
      |1=''[[Numidotherium koholense]]''  [[File:Numidotherium koholense skull.png|50px]] |bar1=green
      |2={{clade
         |1=''[[Moeritherium lyonsi]]''  [[File:Moeritherium NT crop.jpg|50px]]  |bar1=green
         |2={{clade
            |1=[[Deinotheriidae]]  [[File:Deinotherium12.jpg|40px]]        |bar1=green
            |label2=[[Elephantiformes]]
            |2={{clade
               |1=''[[Palaeomastodon beadnelli]]''  [[File:Palaeomastodon NT small.jpg|50px]] 
               |label2=[[Elephantimorpha]]
               |2={{clade
                  |1={{clade
                     |label1=[[Mammutida]]
                     |1={{clade
                        |1=''[[Mammut americanum]]''  [[File:Mammut americanum.png|50px]] 
                        |2=''[[Zygolophodon borsoni]]''  [[File:Mammut borsoni from Milia.jpg|50px]] 
                        }}
                     }}
                  |2={{clade
                     |1=''[[Choerolophodon pentelici]]''      |bar1=purple
                     |2={{clade
                        |1=''[[Gomphotherium augustidens]]''  [[File:Gomphotherium NT small (flipped).jpg|50px]]  |bar1=purple
                        |2={{clade
                           |1=''[[Cuvieronius andium]]''  [[File:Cuvieronius hyodon2.jpg|50px]]       |bar1=purple
                           |2=''[[Stegomastodon humboldti]]''  [[File:Stegomastodon sp.png|50px]] |bar2=purple
                           |label3=[[Elephantoidea]]
                           |3={{clade
                              |1=''[[Stegodon insignis]]''  [[File:Stegodon ganesaDB.jpg|50px]]
                              |label2=[[Elephantidae]]
                              |2={{clade
                                 |1={{clade
                                    |1={{clade
                                       |1=''[[Mammuthus meridionalis]]''  [[File:Mammuthus meridionalis reconstruction 2.jpg|50px]]
                                       |2=''[[Mammuthus primigenius]]''  [[File:202003 Woolly mammoth.png|50px]]
                                       |3=''[[Mammuthus columbi]]''  [[File:Archidiskodon imperator121.jpg|50px]]
                                       }}
                                    |2=''[[Elephas maximus]]''  [[File:Indian elephant (PSF).png|50px]]
                                    }}
                                 |2=''[[Loxodonta africana]]''  [[File:African elephant (PSF).png|50px]]
                                 |label3=''[[Palaeoloxodon]]''
                                 |3={{clade
                                    |1=''[[Palaeoloxodon antiquus]]''  [[File:Palaeoloxodon_antiquus_size_comparison.png|50px]]
                                    |2=''[[Palaeoloxodon falconeri]]''  [[File:Palaeoloxodon_falconeri_Size_Comparison.svg|40px]]
                                    }}
                                 }}
                              }}
                           }}
                        }}
                     }}
                  }}
               }}
            }}
         }}
      }}
   }}
}}

== Morphology ==
{{gallery|Moeritherium lyonsi size comparison.png|Skeleton of the primitive proboscidean ''[[Moeritherium lyonsi]]''|Deinotherium skeletals alternate.png|Skeletons of ''[[Deinotherium]]'' ([[Deinotheriidae]])|Gomphotherium_skeletals.png|Skeletons of two species of the [[gomphothere]] ''[[Gomphotherium]]''|Stegodon_skeletal.png|Skeleton of ''[[Stegodon zdanskyi]]'' ([[Stegodontidae]])|Warren_mastodon_size_comparison.jpg|Skeleton of the [[American mastodon]], ''Mammut americanum'' ([[Mammutidae]])|||width=185|height=|lines=|align=center|title=Gallery of Proboscidean skeletons}}

Over the course of their evolution, proboscideans experienced a significant increase in body size. Some members of the families [[Deinotheriidae]], [[Mammutidae]], [[Stegodontidae]] and [[Elephantidae]] are thought to have exceeded modern elephants in size, with shoulder heights over {{Convert|4|m|ft}} and masses over {{Convert|10|tonne|lb}}, with average fully grown males of the mammutid ''[["Mammut" borsoni]]'' having an estimated body mass of {{Convert|16|tonne|lb}}, making it one the largest and perhaps the largest land mammal ever, with a fragmentary specimen of the Indian elephant species ''[[Palaeoloxodon namadicus]]'' only known from a partial femur being speculatively estimated in the same study to have possibly reached a body mass of {{Convert|22|tonne|lb}}.<ref name="Larramendi, A. 2015">{{cite journal |author=Larramendi A |year=2015 |title=Shoulder height, body mass and shape of proboscideans |journal=Acta Palaeontologica Polonica |doi=10.4202/app.00136.2014 |doi-access=free}}</ref> As with other [[megaherbivore]]s, including the extinct [[Sauropoda|sauropod]] dinosaurs, the large size of proboscideans likely developed to allow them to survive on vegetation with low nutritional value.<ref>{{cite book |author=Carpenter, K. |title=Paleontology and Geology of the Upper Jurassic Morrison Formation |publisher=New Mexico Museum of Natural History and Science |year=2006 |editor=Foster, J.R. |series=New Mexico Museum of Natural History and Science Bulletin |volume=36 |pages=131–138 |chapter=Biggest of the big: a critical re-evaluation of the mega-sauropod ''Amphicoelias fragillimus'' Cope, 1878 |editor2=Lucas, S.G.}}</ref> Their limbs grew longer and the feet shorter and broader.<ref name="evolution">{{cite journal |author=Shoshani, J. |year=1998 |title=Understanding proboscidean evolution: a formidable task |journal=Trends in Ecology and Evolution |volume=13 |issue=12 |pages=480–87 |doi=10.1016/S0169-5347(98)01491-8 |pmid=21238404|bibcode=1998TEcoE..13..480S }}</ref> The feet were originally [[plantigrade]] and developed into a [[digitigrade]] stance with cushion pads and the [[sesamoid bone]] providing support, with this change developing around the common ancestor of [[Deinotheriidae]] and [[Elephantiformes]].<ref>{{cite journal |author1=Hutchinson, J. R. |author2=Delmer, C. |author3=Miller, C. E. |author4=Hildebrandt, T. |author5=Pitsillides, A. A. |author6=Boyde, A. |year=2011 |title=From flat foot to fat foot: structure, ontogeny, function, and evolution of elephant 'sixth toes' |url=https://researchonline.rvc.ac.uk/id/eprint/5612/1/5612.pdf |url-status=live |journal=Science |volume=334 |issue=6063 |pages=1699–1703 |bibcode=2011Sci...334R1699H |doi=10.1126/science.1211437 |pmid=22194576 |s2cid=206536505 |archive-url=https://web.archive.org/web/20230321084756/https://rvc-repository.worktribe.com |archive-date=21 March 2023 |access-date=3 January 2023}}</ref> Members of [[Elephantiformes]] and Deinotheriidae have retracted nasal regions of the skull indicating the development of a trunk.<ref>{{Cite book |last=Sanders |first=William J. |url=https://www.taylorfrancis.com/books/9781315118918 |title=Evolution and Fossil Record of African Proboscidea |date=2023-07-07 |publisher=CRC Press |isbn=978-1-315-11891-8 |edition=1 |location=Boca Raton |pages=79 |language=en |doi=10.1201/b20016}}</ref><ref name=":3">{{Cite journal |last=Nabavizadeh |first=Ali |date=2024-10-08 |title=Of tusks and trunks: A review of craniofacial evolutionary anatomy in elephants and extinct Proboscidea |url=https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25578 |journal=The Anatomical Record |language=en |doi=10.1002/ar.25578 |issn=1932-8486|url-access=subscription }}</ref>   

The skull grew larger, especially the cranium, while the neck shortened to provide better support for the skull. The increase in size led to the development and elongation of the mobile trunk to provide reach. The number of [[premolar]]s, incisors and [[Canine tooth|canines]] decreased. The cheek teeth (molars and premolars) became larger and more specialised.<ref name="evolution" /> In Elephantiformes, the second upper incisor and lower incisor were transformed into ever growing [[tusk]]s on the upper and lower jaws,<ref>{{Cite journal |last=Ferretti |first=Marco P. |date=March 2008 |title=Enamel Structure of Cuvieronius hyodon (Proboscidea, Gomphotheriidae) with a Discussion on Enamel Evolution in Elephantoids |url=http://link.springer.com/10.1007/s10914-007-9057-3 |journal=Journal of Mammalian Evolution |language=en |volume=15 |issue=1 |pages=37–58 |doi=10.1007/s10914-007-9057-3 |s2cid=21216371 |issn=1064-7554}}</ref><ref>{{Cite journal |last=Delmer |first=Cyrille |date=December 2009 |title=Reassessment of the Generic Attribution of Numidotherium savagei and the Homologies of Lower Incisors in Proboscideans |url=http://www.app.pan.pl/article/item/app20070036.html |journal=Acta Palaeontologica Polonica |language=en |volume=54 |issue=4 |pages=561–580 |doi=10.4202/app.2007.0036 |s2cid=55095894 |issn=0567-7920|doi-access=free }}</ref> while in Deinotheriidae there are only tusks on the lower jaw.<ref name=":3" /> The tusks are proportionally heavy for their size, being primarily composed of [[dentine]]. In primitive proboscideans, a band of enamel covers part of the tusk surface, though in many later groups including modern elephants the band is lost, with elephants only having enamel on the tusk tips of juveniles. The upper tusks were initially modest in size, but from the Late Miocene onwards proboscideans developed increasingly large tusks, with the longest ever recorded tusk being {{Convert|5.02|m|ft}} long belonging to the mammutid ''[["Mammut" borsoni]]'' found in Greece, with some mammoth tusks likely weighing over {{Convert|200|kg|lb}}. The lower tusks are generally smaller than the upper tusks, but could grow to large sizes in some species, like in ''[[Deinotherium]]'' (which lacks upper tusks), where they could grow over {{Convert|1.5|m|ft}} long, the [[Amebelodontidae|amebelodontid]] ''[[Konobelodon]]'' has lower tusks {{Convert|1.61|m|ft}} long, with the longest lower tusks ever recorded being from the primitive elephantid ''[[Stegotetrabelodon]]'' which are around {{Convert|2.2|m|ft}} long.<ref>{{Cite journal |last=Larramendi |first=Asier |date=2023-12-10 |title=Estimating tusk masses in proboscideans: a comprehensive analysis and predictive model |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2023.2286272 |journal=Historical Biology |language=en |pages=1–14 |doi=10.1080/08912963.2023.2286272 |issn=0891-2963|url-access=subscription }}</ref> 

The molar teeth changed from being replaced vertically as in other mammals to being replaced horizontally in the clade [[Elephantimorpha]].<ref>{{Cite journal |last=Sanders |first=William J. |date=2018-02-17 |title=Horizontal tooth displacement and premolar occurrence in elephants and other elephantiform proboscideans |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2017.1297436 |journal=Historical Biology |language=en |volume=30 |issue=1–2 |pages=137–156 |doi=10.1080/08912963.2017.1297436 |bibcode=2018HBio...30..137S |s2cid=89904463 |issn=0891-2963|url-access=subscription }}</ref>  While early Elephantimorpha generally had lower jaws with an elongated [[mandibular symphysis]] at the front of the jaw with well developed lower tusks/incisors, from the Late Miocene onwards, many groups convergently developed brevirostrine (shortened) lower jaws with vestigial or no lower tusks.<ref>{{cite journal |last1=Mothé |first1=Dimila |last2=Ferretti |first2=Marco P. |last3=Avilla |first3=Leonardo S. |date=12 January 2016 |title=The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha |journal=PLOS ONE |volume=11 |issue=1 |page=e0147009 |bibcode=2016PLoSO..1147009M |doi=10.1371/journal.pone.0147009 |pmc=4710528 |pmid=26756209 |doi-access=free}}</ref><ref>{{Cite report |url=http://biorxiv.org/lookup/doi/10.1101/2023.08.15.553347 |title=Longer mandible or nose? Co-evolution of feeding organs in early elephantiforms |last1=Li |first1=Chunxiao |last2=Deng |first2=Tao |date=2023-08-16 |publisher=Paleontology |doi=10.1101/2023.08.15.553347 |language=en |last3=Wang |first3=Yang |last4=Sun |first4=Fajun |last5=Wolff |first5=Burt |last6=Jiangzuo |first6=Qigao |last7=Ma |first7=Jiao |last8=Xing |first8=Luda |last9=Fu |first9=Jiao}}</ref> Elephantids are distinguished from other proboscideans by a major shift in the molar morphology to parallel lophs rather than the cusps of earlier proboscideans, allowing them to become higher crowned (hypsodont) and more efficient in consuming grass.<ref>{{Cite journal |last=Lister |first=Adrian M. |date=2013-06-26 |title=The role of behaviour in adaptive morphological evolution of African proboscideans |url=http://dx.doi.org/10.1038/nature12275 |journal=Nature |volume=500 |issue=7462 |pages=331–334 |bibcode=2013Natur.500..331L |doi=10.1038/nature12275 |issn=0028-0836 |pmid=23803767 |s2cid=883007|url-access=subscription }}</ref> 

=== Dwarfism ===
{{main|Dwarf elephant}}
[[File:Palaeoloxodon falconeri Size Comparison.svg|thumb|Size comparison of the dwarf elephant ''[[Palaeoloxodon falconeri]]'' from the Pleistocene of Sicily and Malta to a human]]
Several species of proboscideans lived on islands and experienced [[insular dwarfism]]. This occurred primarily during the Pleistocene, when some elephant populations became isolated by fluctuating sea levels, although dwarf elephants did exist earlier in the Pliocene. These elephants likely grew smaller on islands due to a lack of large or viable predator populations and limited resources. By contrast, small mammals such as rodents develop [[Island gigantism|gigantism]] in these conditions. Dwarf proboscideans are known to have lived in [[Indonesia]], the [[Channel Islands of California]], and several islands of the [[Mediterranean Sea|Mediterranean]].<ref name=Sukumar31/>

''[[Elephas celebensis]]'' of [[Sulawesi]] is believed to have descended from ''[[Elephas planifrons]]''. ''[[Palaeoloxodon falconeri|Elephas falconeri]]'' of [[Malta]] and [[Sicily]] was only {{convert|1|m|ft|0|abbr=on}}, and had probably evolved from the [[straight-tusked elephant]]. Other descendants of the straight-tusked elephant existed in [[Cyprus]]. Dwarf elephants of uncertain descent lived in [[Crete]], [[Cyclades]] and [[Dodecanese]], while dwarf mammoths are known to have lived in [[Sardinia]].<ref name=Sukumar31>Sukumar, pp. 31–33.</ref> The [[Columbian mammoth]] colonised the [[Channel Islands of California|Channel Islands]] and evolved into the [[pygmy mammoth]]. This species reached a height of {{convert|1.2|–|1.8|m|ft|0|abbr=on}} and weighed {{convert|200|–|2000|kg|lb|abbr=on}}. A population of small woolly mammoths survived on [[Wrangel Island]] as recently as 4,000 years ago.<ref name=Sukumar31/> After their discovery in 1993, they were considered dwarf mammoths.<ref name=Nature>{{cite journal | author = Vartanyan, S. L., Garutt, V. E., Sher, A. V. | date = 1993 | title = Holocene dwarf mammoths from Wrangel Island in the Siberian Arctic | journal = [[Nature (journal)|Nature]] | volume = 362 | pages = 337–40 | doi=10.1038/362337a0 | issue=6418| pmid = 29633990 | bibcode = 1993Natur.362..337V | s2cid = 4249191 }}</ref> This classification has been re-evaluated and since the [[Second International Mammoth Conference]] in 1999, these animals are no longer considered to be true "dwarf mammoths".<ref>{{cite journal |author=Tikhonov, A.; Agenbroad, L.; Vartanyan, S. |date=2003 |title=Comparative analysis of the mammoth populations on Wrangel Island and the Channel Islands |journal=Deinsea |volume=9 |issue= |pages=415–20 |issn=0923-9308}}</ref>

== Ecology ==
It has been suggested that members of Elephantimorpha, including mammutids,<ref name=":1">{{Cite journal |last1=Miller |first1=Joshua H. |last2=Fisher |first2=Daniel C. |last3=Crowley |first3=Brooke E. |last4=Secord |first4=Ross |last5=Konomi |first5=Bledar A. |date=2022-06-21 |title=Male mastodon landscape use changed with maturation (late Pleistocene, North America) |journal=Proceedings of the National Academy of Sciences |language=en |volume=119 |issue=25 |pages=e2118329119 |doi=10.1073/pnas.2118329119 |doi-access=free |issn=0027-8424 |pmc=9231495 |pmid=35696566|bibcode=2022PNAS..11918329M }}</ref> gomphotheres,<ref>{{Cite journal |last1=Mothé |first1=Dimila |last2=Avilla |first2=Leonardo S. |last3=Winck |first3=Gisele R. |date=December 2010 |title=Population structure of the gomphothere Stegomastodon waringi (Mammalia: Proboscidea: Gomphotheriidae) from the Pleistocene of Brazil |journal=Anais da Academia Brasileira de Ciências |language=en |volume=82 |issue=4 |pages=983–996 |doi=10.1590/S0001-37652010005000001 |issn=0001-3765 |pmid=21152772 |doi-access=free}}</ref> and stegodontids,<ref>{{Cite journal |last1=Matsukawa |first1=Masaki |last2=Shibata |first2=Kenichiro |date=2015-10-02 |title=Review of Japanese Cenozoic (Miocene–Modern) Vertebrate Tracks |url=http://www.tandfonline.com/doi/full/10.1080/10420940.2015.1064407 |journal=Ichnos |language=en |volume=22 |issue=3–4 |pages=261–290 |bibcode=2015Ichno..22..261M |doi=10.1080/10420940.2015.1064407 |issn=1042-0940 |s2cid=129206332|url-access=subscription }}</ref> lived in herds like modern elephants. Analysis of remains of the American mastodon (''Mammut americanum'') suggest that like modern elephants, that herds consisted of females and juveniles and that adult males lived solitarily or in small groups, and that adult males periodically engaged in fights with other males during periods similar to [[musth]] found in living elephants. These traits are suggested to be inherited from the last common ancestor of elephantimorphs,<ref name=":1" /> with musth-like behaviour also suggested to have occurred in gomphotheres.<ref>{{Cite journal |last1=El Adli |first1=Joseph J. |last2=Fisher |first2=Daniel C. |last3=Cherney |first3=Michael D. |last4=Labarca |first4=Rafael |last5=Lacombat |first5=Frédéric |date=July 2017 |title=First analysis of life history and season of death of a South American gomphothere |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618216302634 |journal=Quaternary International |language=en |volume=443 |pages=180–188 |bibcode=2017QuInt.443..180E |doi=10.1016/j.quaint.2017.03.016|url-access=subscription }}</ref> All elephantimorphs are suggested to have been capable of communication via [[infrasound]], as found in living elephants.<ref>{{Citation |last1=Benoit |first1=Julien |title=Paleoneurology of the Proboscidea (Mammalia, Afrotheria): Insights from Their Brain Endocast and Labyrinth |date=2023 |work=Paleoneurology of Amniotes |pages=579–644 |editor-last=Dozo |editor-first=María Teresa |url=https://link.springer.com/10.1007/978-3-031-13983-3_15 |access-date=2024-04-20 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-13983-3_15 |isbn=978-3-031-13982-6 |last2=Lyras |first2=George A. |last3=Schmitt |first3=Arnaud |last4=Nxumalo |first4=Mpilo |last5=Tabuce |first5=Rodolphe |last6=Obada |first6=Teodor |last7=Mararsecul |first7=Vladislav |last8=Manger |first8=Paul |editor2-last=Paulina-Carabajal |editor2-first=Ariana |editor3-last=Macrini |editor3-first=Thomas E. |editor4-last=Walsh |editor4-first=Stig|url-access=subscription }}</ref> Deinotheres may have also lived in herds, based on tracks found in the Late Miocene of Romania.<ref>{{Cite journal |last1=Neto de Carvalho |first1=Carlos |last2=Belaústegui |first2=Zain |last3=Toscano |first3=Antonio |last4=Muñiz |first4=Fernando |last5=Belo |first5=João |last6=Galán |first6=Jose María |last7=Gómez |first7=Paula |last8=Cáceres |first8=Luis M. |last9=Rodríguez-Vidal |first9=Joaquín |last10=Cunha |first10=Pedro Proença |last11=Cachão |first11=Mario |last12=Ruiz |first12=Francisco |last13=Ramirez-Cruzado |first13=Samuel |last14=Giles-Guzmán |first14=Francisco |last15=Finlayson |first15=Geraldine |date=2021-09-16 |title=First tracks of newborn straight-tusked elephants (Palaeoloxodon antiquus) |journal=Scientific Reports |language=en |volume=11 |issue=1 |page=17311 |bibcode=2021NatSR..1117311N |doi=10.1038/s41598-021-96754-1 |issn=2045-2322 |pmc=8445925 |pmid=34531420}}</ref> Over the course of the Neogene and Pleistocene, various members of [[Elephantida]] shifted from a browse-dominated diet towards mixed feeding or grazing.<ref>{{Cite journal |last1=Saarinen |first1=Juha |last2=Lister |first2=Adrian M. |date=2023-08-14 |title=Fluctuating climate and dietary innovation drove ratcheted evolution of proboscidean dental traits |journal=Nature Ecology & Evolution |language=en |volume=7 |issue=9 |pages=1490–1502 |doi=10.1038/s41559-023-02151-4 |issn=2397-334X |pmc=10482678 |pmid=37580434|bibcode=2023NatEE...7.1490S }}</ref>

== Classification ==
Below is a taxonomy of proboscidean genera as of 2019.<ref name="Shoshani & Tassy (2005)">{{cite journal |last=Shoshani |first=Jeheskel |author2=Pascal Tassy |year=2005 |title=Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior |journal=Quaternary International |volume=126–128 |pages=5–20 |bibcode=2005QuInt.126....5S |doi=10.1016/j.quaint.2004.04.011}}</ref><ref>{{cite journal|doi=10.1080/14772019.2016.1208687|title=Morphological and ecological diversity of Amebelodontidae (Proboscidea, Mammalia) revealed by a Miocene fossil accumulation of an upper-tuskless proboscidean|journal=Journal of Systematic Palaeontology|volume=15|issue=8|pages=601–615|year=2017|last1=Wang|first1=Shi-Qi|last2=Deng|first2=Tao|last3=Ye|first3=Jie|last4=He|first4=Wen|last5=Chen|first5=Shan-Qin|bibcode=2017JSPal..15..601W |s2cid=89063787}}</ref><ref name="Mothé et al 2016">{{cite journal|last1=Mothé|first1=Dimila|last2=Ferretti|first2=Marco P.|last3=Avilla|first3=Leonardo S.|title=The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha|journal=PLOS ONE|volume=11|pages=e0147009|date=12 January 2016|issue=1|doi=10.1371/journal.pone.0147009|pmid=26756209|pmc=4710528|bibcode=2016PLoSO..1147009M|doi-access=free}}</ref><ref>{{cite journal|doi=10.1017/jpa.2019.98|title=Filling a gap in the proboscidean fossil record: a new genus from the Lutetian of Senegal|journal=Journal of Paleontology|year=2019|last1=Tabuce|first1=Rodolphe|last2=Sarr|first2=Raphaël|last3=Adnet|first3=Sylvain|last4=Lebrun|first4=Renaud|last5=Lihoreau|first5=Fabrice|last6=Martin|first6=Jeremy|last7=Sambou|first7=Bernard|last8=Thiam|first8=Mustapha|last9=Hautier|first9=Lionel|volume=94|issue=3|pages=580–588|s2cid=213978026|url=https://hal.archives-ouvertes.fr/hal-02408861/file/Tabuce-Saloumia.pdf}}</ref>

*Order '''Proboscidea''' Illiger, 1811
**†''[[Eritherium]]'' Gheerbrant, 2009
**†''[[Moeritherium]]'' Andrews, 1901
**†''[[Saloumia]]'' Tabuce ''et al.'', 2019
**†Family [[Numidotheriidae]] Shoshani & Tassy, 1992
***†''[[Phosphatherium]]'' Gheerbrant ''et al.'', 1996
***†''[[Arcanotherium]]'' Delmer, 2009
***†''[[Daouitherium]]'' Gheerbrant & Sudre, 2002
***†''[[Numidotherium]]'' Mahboubi ''et al.'', 1986
**†Family [[Barytheriidae]] Andrews, 1906
***†''[[Omanitherium]]'' Seiffert ''et al.'', 2012
***†''[[Barytherium]]'' Andrews, 1901
**†Family [[Deinotheriidae]] Bonaparte, 1845
***†''[[Chilgatherium]]'' Sanders ''et al.'', 2004
***†''[[Prodeinotherium]]'' Ehik, 1930
***†''[[Deinotherium]]'' Kaup, 1829
**Suborder [[Elephantiformes]] Tassy, 1988
***†''[[Eritreum]]'' Shoshani ''et al.'', 2006
***†''[[Hemimastodon]]'' Pilgrim, 1912
***†''[[Palaeomastodon]]'' Andrews, 1901
***†''[[Phiomia]]'' Andrews & Beadnell, 1902
***Infraorder [[Elephantimorpha]] Tassy & Shoshani, 1997
****†Family [[Mammutidae]] Hay, 1922
*****†''[[Losodokodon]]'' Rasmussen & Gutierrez, 2009
*****†''[[Eozygodon]]'' Tassy & Pickford, 1983
*****†''[[Zygolophodon]]'' Vacek, 1877
*****†''[[Sinomammut]]'' Mothé ''et al.'', 2016
*****†''[[Mammut]]'' Blumenbach, 1799
****Parvorder [[Elephantida]] Tassy & Shoshani, 1997
*****†Family [[Choerolophodontidae]] Gaziry, 1976
******†''[[Afrochoerodon]]'' Pickford, 2001
******†''[[Choerolophodon]]'' Schlesinger, 1917
*****†Family [[Amebelodontidae]] Barbour, 1927
******†''[[Afromastodon]]'' Pickford, 2003
******†''[[Progomphotherium]]'' Pickford, 2003
******†''[[Eurybelodon]]'' Lambert, 2016
******†''[[Serbelodon]]'' Frick, 1933
******†''[[Archaeobelodon]]'' Tassy, 1984
******†''[[Protanancus]]'' Arambourg, 1945
******†''[[Amebelodon]]'' Barbour, 1927
******†''[[Konobelodon]]'' Lambert, 1990
******†''[[Torynobelodon]]'' Barbour, 1929
******†''[[Aphanobelodon]]'' Wang ''et al.'', 2016
******†''[[Platybelodon]]'' Borissiak, 1928
*****†Family [[Gomphotheriidae]] Hay, 1922 ([[paraphyletic]])
******"trilophodont gomphotheres"
*******†''[[Gomphotherium]]'' Burmeister, 1837
*******†''[[Blancotherium]]'' May, 2019
*******†''[[Gnathabelodon]]'' Barbour & Sternberg, 1935
*******†''[[Eubelodon]]'' Barbour, 1914
*******†''[[Stegomastodon]]'' Pohlig, 1912
*******†''[[Sinomastodon]]'' Tobien ''et al.'', 1986
*******†''[[Notiomastodon]]'' Cabrera, 1929
*******†''[[Rhynchotherium]]'' Falconer, 1868
*******†''[[Cuvieronius]]'' Osborn, 1923
******"tetralophodont gomphotheres"
*******†''[[Anancus]]'' Aymard, 1855
*******†''[[Paratetralophodon]]'' Tassy, 1983
*******†''[[Pediolophodon]]'' Lambert, 2007
*******†''[[Tetralophodon]]'' Falconer, 1857
*****Superfamily [[Elephantoidea]] Gray, 1821
******†Family [[Stegodontidae]] Osborn, 1918
*******†''[[Stegolophodon]]'' Schlesinger, 1917
*******†''[[Stegodon]]'' Falconer, 1857
******Family [[Elephantidae]] Gray, 1821
*******†''[[Stegodibelodon]]'' Coppens, 1972
*******†''[[Stegotetrabelodon]]'' Petrocchi, 1941
*******†''[[Selenotherium]]'' Mackaye, Brunet & Tassy, 2005
*******†''[[Primelephas]]'' Maglio, 1970
*******''[[Loxodonta]]'' Anonymous, 1827
*******†''[[Palaeoloxodon]]'' Matsumoto, 1924
*******†''[[Mammuthus]]'' Brookes, 1828
*******''[[Elephas]]'' Linnaeus, 1758

==References==
{{Reflist|refs=Debruyne, R. D., Chu, G., King, C. E., Bos, K., Kuch, M., Schwarz, C., Paul Szpak, P., Gröcke, D. R., Matheus, P., Zazula, G., Guthrie, D., Froese, D., Buigues, B., Marliave, C. de, Flemming, C., Poinar, D., Phoinar, H. N., MacPhee, R. D. E., Tikhonov, A. N., … Fisher, D. (2008, September 9). Out of America: ancient DNA evidence for a new world origin of late quaternary woolly mammoths. CB. https://pubmed.ncbi.nlm.nih.gov/18771918/.  DOI: 10.1016/j.cub.2008.07.061}}

==Bibliography==
* {{citation | first = Ronald M. | last = Nowak | title = Walker's Mammals of the World | isbn = 978-0-8018-5789-8 | year = 1999 | publisher = Johns Hopkins University Press | location = Baltimore | edition = 6th | lccn = 98023686 | language = en <!--| GBS-id = T37sFCl43E8C | Ltwork = 257350 -->}}
* {{citation | last = Haynes | first = Gary | title = Mammoths, Mastodonts, and Elephants: Biology, Behavior and the Fossil Record | publisher = Cambridge University Press | date = 1993 | url = https://books.google.com/books?id=PRrZ-TK91LMC | language = en | edition = 2nd | isbn = 9780521456913}}

* {{cite book |author=Sukumar, R. |url=https://archive.org/details/livingelephantse00suku_0 |title=The Living Elephants: Evolutionary Ecology, Behaviour, and Conservation |date=11 September 2003 |publisher=Oxford University Press, USA |isbn=978-0-19-510778-4 |oclc=935260783 |url-access=registration}}
{{Wikispecies|Proboscidea}}{{Commons category|Proboscidea}}
{{Wikibooks|Dichotomous Key|Proboscidea}}
{{Wiktionary|Proboscidea}}
{{Wikisource|1911 Encyclopædia Britannica/Proboscidea|Proboscidea }}

{{Mammals}}
{{Paenungulata|state=autocollapse}}
{{Proboscidea Genera}}
{{Proboscidea}}

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[[Category:Proboscideans| ]]
[[Category:Mammal orders]]
[[Category:Selandian first appearances]]
[[Category:Taxa named by Johann Karl Wilhelm Illiger]]
[[Category:Extant Selandian first appearances]]