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{{Short description|Extinct genus of proboscideans}}
{{About|the genus|the social networking platform|Mastodon (social network)|the band|Mastodon (band)|other uses|Mastodon (disambiguation)}}
{{Redirect|Mammut|other uses|Mammut (disambiguation)}}
{{Automatic taxobox
| name = Mastodon
| taxon = Mammut
| fossil_range = Late [[Miocene]] – early [[Holocene]] {{fossilrange|8|0.011|earliest=10}} (Possible earliest record of up to ~10&nbsp;[[megaannum|Ma]])
| image = Mastodon skeleton at AMNH.jpg
| image_caption = Mounted ''M. americanum'' skeleton ("Warren mastodon"), [[American Museum of Natural History]]
| authority = [[Johann Friedrich Blumenbach|Blumenbach]], 1799
| type_species = {{extinct}}''Elephas americanus'' <br>(= †'''''Mammut americanum''''')
| type_species_authority = [[Robert Kerr (writer)|Kerr]], 1792
| subdivision_ranks = Other species
| subdivision = {{species list
| {{extinct}}'''''M. matthewi'''''|[[Henry Fairfield Osborn|Osborn]], 1921
| {{extinct}}'''''M. vexillarius'''''|[[William Diller Matthew|Matthew]], 1930
| {{extinct}}'''''M. raki'''''|[[Childs Frick|Frick]], 1933
| {{extinct}}'''''M. nevadanum'''''|[[Chester Stock|Stock]], 1936
| {{extinct}}'''''M. cosoensis'''''|Schultz, 1937
| {{extinct}}'''''M? furlongi'''''|Shotwell & Russell, 1963
| {{extinct}}'''''M. pacificum'''''|Dooley ''et al''., 2019
}}
{{collapsible list|bullets = true
|title=<small>Species pending reassessment</small>
| {{extinct}}'''''[["Mammut" borsoni|M. borsoni]]''''' <small>[[Isaac Hays|Hays]], 1834</small>
| {{extinct}}'''''M. obliquelophus''''' <small>Mucha, 1980</small>
| {{extinct}}'''''M. lufugense''''' <small>Zhang, 1982</small>
| {{extinct}}'''''M. zhupengensis''''' <small>Zhang et. al., 1991</small>
}}
| synonyms = {{collapsible list |bullets = true |title=<small>Genus synonymy</small>
 | ''Harpagmotherium'' {{small|[[Gotthelf Fischer von Waldheim|Fischer von Waldheim]], 1808}}
 | ''Mastotherium'' {{small|Fischer von Waldheim, 1814}}
 | ''Mastodon'' {{small|[[Georges Cuvier|Cuvier]], 1817}}
 | ''Tetracaulodon'' {{small|[[John Davidson Godman|Godman]], 1830}}
 | ''Missourium'' {{small|[[Albert C. Koch|Koch]], 1840}}
 | ''Leviathan'' {{small|Koch, 1841}}
 | ''Pliomastodon'' {{small|Osborn, 1926}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. americanum''</small>
 | ''Elephas americanus'' {{small|Kerr, 1792}}
 | ''Mammut ohioticum'' {{small|Blumenbach, 1799}}
 | ''Elephas macrocephalus'' {{small|Camper, 1802}}
 | ''Harpagmotherium canadense'' {{small|Fischer de Waldheim, 1808}}
 | ''Elephas mastodontus'' {{small|[[Benjamin Smith Barton|Barton]], 1810}}
 | ''Mastotherium megalodon'' {{small|Fischer de Waldheim, 1814}}
 | ''Tapirus mastodontoides'' {{small|[[Richard Harlan|Harlan]], 1825}}
 | ''Tetracaulodon mastodontoideum'' {{small|Godman, 1830}}
 | ''Mastodon ohioticum'' {{small|[[Karl Eichwald|Eichwald]], 1832}}
 | ''Mastodon cuvieri'' {{small|Hays, 1834}}
 | ''Mastodon jeffersoni'' {{small|Hays, 1834}}
 | ''Tetracaulodon collinsii'' {{small|Hays, 1834}}
 | ''Tetracaulodon godmani'' {{small|Hays, 1834}}
 | ''Tetracaulodon tapyroides'' {{small|Hays, 1834}}
 | ''Elephas ohioticus'' {{small|[[Henri Marie Ducrotay de Blainville|de Blainville]], 1839–1864}}
 | ''Missourium kochii'' {{small|Koch, 1840}}
 | ''Leviathan missourii'' {{small|Koch, 1840}}
 | ''Tetracaulodon osagii'' {{small|Koch, 1841}}
 | ''Tetracaulodon kochii'' {{small|Koch, 1841}}
 | ''Tetracaulodon bucklandii'' {{small|Grant, 1842}}
 | ''Missourium theristocaulodon'' {{small|Koch, 1843}}
 | ''Mastodon rugatum'' {{small|Koch, 1845}}
 | ''Elephas rupertianus'' {{small|[[John Richardson (naturalist)|Richardson]], 1854}}
 | ''Trilophodon ohioticus'' {{small|[[Hugh Falconer|Falconer]], 1868}}
 | ''Mammut progenium'' {{small|[[Oliver P. Hay|Hay]], 1914}}
 | ''Mastodon americanus plicatus'' {{small|Osborn, 1926}}
 | ''Mammut oregonense'' {{small|Hay, 1926}}
 | ''Mastodon moodiei'' {{small|[[Erwin Hinckley Barbour|Barbour]], 1931}}
 | ''Mastodon americanus alaskensis'' {{small|Frick, 1933}}
 | ''Mastodon acutidens'' {{small|Osborn, 1936}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. matthewi''</small>
 | ''Mastodon matthewi'' {{small|Osborn, 1921}}
 | ''Pliomastodon sellardsi'' {{small|[[George Gaylord Simpson|Simpson]], 1930}}
 | ''Pliomastodon adamsi'' {{small|[[Claude W. Hibbard|Hibbard]], 1944}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. vexillarius''</small>
 | ''Pliomastodon vexillarius'' {{small|Matthew, 1930}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. raki''</small>
 | ''Mastodon raki'' {{small|Frick, 1933}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. nevadanum''</small>
 | ''Pliomastodon nevadanus'' {{small|Stock, 1936}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of ''M. cosoensis''</small>
 | ''Pliomastodon cosoensis'' {{small|Schultz, 1937}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of "''M.''" ''borsoni''</small>
 | ''Mastodon vellavus'' {{small|[[Auguste Aymard|Aymard]], 1847}}
 | ''Mastodon vialleti'' {{small|Aymard, 1847}}
 | ''Mastodon buffonis'' {{small|[[Auguste Pomel|Pomel]], 1848}}
 | ''Mastodon affinis'' {{small|Pomel, 1859}}
 | ''Zygolophodon borsoni'' {{small|Osborn, 1926}}
 | ''Mastodon pavlowi'' {{small|Osborn, 1936}}
 | ''Mammut shansiense'' {{small|Chow & Chang, 1961}}
}}
{{collapsible list|bullets = true
 |title=<small>Synonyms of "''M.''" ''obliquelophus''</small>
 | ''M. praetypicum?'' {{small|Schlesinger, 1917}}
}}
}}

A '''mastodon''' ({{wikt-lang|grc-Latn|μαστός|mastós}} 'breast' + {{wikt-lang|grc-Latn|ὀδούς|odoús}} 'tooth') is a member of the genus '''''Mammut''''' (German for "mammoth"), which, strictly defined, was endemic to North America and lived from the late [[Miocene]] to the early [[Holocene]]. Mastodons belong to the order [[Proboscidea]], the same order as [[elephant]]s and [[mammoth]]s (which belong to the family [[Elephantidae]]). ''Mammut'' is the type genus of the extinct family [[Mammutidae]], which diverged from the ancestors of modern elephants at least 27–25&nbsp;million years ago, during the [[Oligocene]].

Like other members of Mammutidae, the [[molar (tooth)|molar]] teeth of mastodons have zygodont morphology (where the [[cusp (anatomy)|cusps]] of the teeth are merged into ridges) strongly different from those of elephantids. In comparison to its likely ancestor ''[[Zygolophodon]]'', ''Mammut'' is characterized by particularly long and upward curving upper tusks, reduced or absent tusks on the lower jaw, as well as the shortening of the [[mandibular symphysis]] (the frontmost part of the lower jaw), the latter two traits also [[Parallel evolution|evolved in parallel]] separately in elephantids. Mastodons had an overall stockier skeletal build and a lower-domed skull compared to elephantids. ''M. americanum'' is thought to have been capable of reaching {{cvt|275|cm}} to {{cvt|305|cm}} at shoulder height and from {{cvt|6.8|tonnes}} to {{cvt|9.2|tonnes}} in body mass. The size estimates suggest that the American mastodon was on average larger than the [[Asian elephant]] but smaller than the [[African bush elephant]].

''M. americanum'', known as an "American mastodon" or simply "mastodon," had a long and complex paleontological history spanning all the way back to 1705 when the first fossils were uncovered from [[Claverack, New York|Claverack]], [[New York (state)|New York]] in the American colonies. Naturalists struggled to explain its affinities because of its uniquely shaped molars, which have no modern analogues in terms of large mammals. The American mastodon caught the attention of not only European researchers but also influential Americans before and after the [[American Revolution]]. American historians of the 21st&nbsp;century, such as Paul Semonin and [[Keith Stewart Thomson]], have argued that findings and displays of its fossils had helped to bolster [[American nationalism]] and contributed to a greater understanding of extinctions. It is known by many skeletons which are now typically on display in American museums, a trend first started by [[Charles Willson Peale]] in 1804.

Taxonomically, ''M.&nbsp;americanum'' was first recognized as a distinct species by [[Robert Kerr (writer)|Robert Kerr]] in 1792 then classified to its own genus ''Mammut'' by [[Johann Friedrich Blumenbach]] in 1799, thus making it amongst the first fossil mammal genera to be erected with undisputed taxonomic authority. However, the original genus name was overshadowed by "''Mastodon''" in the 19th century, which was established formally by the French [[naturalist]] [[Georges Cuvier]] in 1817. The genus became problematic as it served as a [[wastebasket taxon]] for many species of proboscideans whose molar teeth morphology superficially resembled those of ''Mammut,'' but were not necessarily closely related. After major revisions of proboscidean taxonomy, the genus ''Mammut'' today is defined as the valid genus name and includes 7&nbsp;definite species, 1 of questionable affinities, and 4&nbsp;other species from Eurasia that are pending reassessments to other genera.

Mastodons are considered to have had a predominantly [[browsing (herbivory)|browsing]]-based diet on leaves, fruits, and woody parts of plants. This allowed mastodons to [[niche partition]] with other members of Proboscidea in North America, like [[gomphothere]]s and the [[Columbian mammoth]], who had shifted to mixed feeding or [[grazing]] by the late [[Neogene]]-[[Quaternary]]. ''Mammut'' achieved maximum species diversity in the [[Pliocene]], though the genus is known from abundant fossil evidence in the [[Late Pleistocene]]. It is thought that mastodons behaviors not much different from elephants and mammoths, with females and juveniles living in herds, while adult males lived largely solitary lives and entered phases of aggression similar to the [[musth]] exhibited by modern elephants.

Mastodons for at least a few thousand years prior to their extinction coexisted with [[Paleoindian]]s, who were the first humans to have inhabited North America. Evidence has been found that Paleoindians (including those of the [[Clovis culture]]) hunted mastodons based on the finding of mastodon remains with cut marks and/or with lithic artifacts.

Mastodons disappeared along with many other North American animals, including most of its largest animals ([[megafauna]]), as part of the [[Late Pleistocene extinctions]] around the end of the Late Pleistocene-early Holocene, the causes typically being attributed to Clovis culture hunting, severe climatic phases like the [[Younger Dryas]], or some combination of the two. The American mastodon had its last recorded occurrence in the earliest Holocene around 11,000&nbsp;years ago, which is considerably later than other North American megafauna species. Today, the American mastodon is one of the most well-known fossil species in both academic research and public perception, the result of its inclusion in American popular culture.

== Research history ==
{{Main|Research history of Mammut|l1=Research history of ''Mammut''}}

=== Earliest finds ===
[[File:Em - Mammut americanum - 9.jpg|thumb|left|''Mammut americanum'' [[molar (tooth)|molar]] tooth, [[Rotunda Museum]]]]
In a letter dating to 1713, [[Edward Hyde, 3rd Earl of Clarendon]] (known also as Lord Cornbury) from [[New York (state)|New York]] reported to the [[Royal Society]] [[learned society]] of [[Great Britain]] that in 1705, a large-sized tooth was found near the side of the [[Hudson River]] by a [[Dutch people|Dutch]] country-fellow and was sold to [[New York General Assembly]] member Van Bruggen for a [[gill (unit)|gill]] of rum, and Bruggen eventually gave it to Cornbury. He then stated that he sent Johannis Abeel, a recorder of [[Albany, New York|Albany]], New York to dig near the original site of the tooth to find more bones.<ref name="stanford"/><ref name="cornbury">{{cite book |last=Weld |first=Charles Richard |year=1848 |title=A History of the Royal Society: With memoirs of the Presidents |chapter=Chapter&nbsp;XV: 1710–1725 |pages=398–433 |url=https://books.google.com/books?id=5CUEAAAAQAAJ }}</ref>

Abeel reported in a later that he went to the town of [[Claverack, New York|Claverack]], New York where the original bones were found. American historian Paul Semonin said that the accounts written by Cornbury and Abeel match up with that written by in the July 30, 1705 entry in ''[[The Boston News-Letter]]''.<ref name="monster">{{cite book|last=Semonin|first=Paul|year=2000|title=American Monster: How the Nation's First Prehistoric Creature Became a Symbol of National Identity|chapter=Chapter 1: The Giant of Claverack in Puritan America|publisher=NYU Press|pages=15–40}}</ref> The account reported skeletal evidence of an [[antediluvian]] (or biblical) "[[giant]]" uncovered from Claverack. The [[femur]] and one of the teeth both dissolved before they could be further observed, however.<ref name="warren">{{cite book|last=Warren|first=John Collin|year=1852|title=The Mastodon giganteus of North America|section=Historical sketch|publisher=John Wilson and Son|pages=1–3|url=https://www.biodiversitylibrary.org/item/126175#page/20/mode/1up}}</ref><ref name="stanford">{{cite journal|last=Stanford|first=Donald E.|year=1959|title=The Giant Bones of Claverack, New York, 1705|journal=New York History|volume=40|number=1|pages=47–61|jstor=23153528 |url=https://www.jstor.org/stable/23153528}}</ref>

=== Big Bone Lick ===
[[File:Proboscidean femurs 1764.png|thumb|Engravings of the femurs of an unspecified extant elephant species (top), ''M.&nbsp;americanum'' (middle), and a "Siberian" mammoth (bottom), 1764]]
In 1739, a French military expedition under the command of [[Charles III Le Moyne]] (known also as "Longueil") explored the locality of "[[Big Bone Lick State Park|Big Bone Lick]]" (located in what is now the US state of [[Kentucky]]) and gathered fossil bones and teeth there.<ref>{{cite journal|last=Storrs |first=Glenn W. |year=2019 |title=Big Bone Lick |journal=Ohio Valley History |volume=19 |number=3 |pages=82–90 |url=https://muse.jhu.edu/article/734797}}</ref> The French naturalist [[Louis Jean-Marie Daubenton]] examined the fossil collection brought by Longueuil and compared it with specimens of extant [[elephant]]s and Siberian [[mammoth]]s in 1762. Daubenton said that the bones were discovered by Native Americans (probably [[Abenaki]] hunter-warriors). He came to the conclusion that the femur and tusk belonged to an elephant while the [[molar (tooth)|molars]] (or cheek teeth) came from a separate giant [[hippopotamus]].<ref>{{cite journal|last=Daubenton|first=Louis Jean-Marie|year=1764|title=Mémoire sur des os et des dents remarquables par leur gradeur|journal=Histoire de l'Académie Royale des Sciences, Année MDCCLXII, avec les Mémoires de Mathématiques & de Physique, pour la même année, 1762|pages=206–229|url=https://books.google.com/books?id=rT1RAAAAYAAJ&pg=RA1-PA206}}</ref><ref name="hedeen">{{cite book|last=Hedeen|first=Stanley|year=2008|title=Big Bone Lick: The Cradle of American Paleontology |chapter=Chapter&nbsp;4: Gathering the bones |publisher=University Press of Kentucky|pages=31–44}}</ref><ref>{{cite journal|last=Barnett|first=Lydia|year=2019|title=Showing and hiding: The flickering visibility of earth workers in the archives of earth science|journal=History of Science|volume=58|issue=3|pages=245–274 |doi=10.1177/0073275319874982|pmid=31640428 }}</ref>

In [[Shawnee]] tradition, the proboscideans roamed in herds and were hunted by giants, who both eventually died out. The accounts told by the Shawnee individuals in 1762 are the oldest known documented interpretations of the "[[Ohio]]" fossils, although the traditions may have had been told for generations.<ref name="monster3">{{cite book |last=Semonin |first=Paul |year=2000 |title=American Monster: How the nation's first prehistoric creature became a symbol of national identity |chapter=Chapter&nbsp;4: Big Bone Lick |publisher=NYU Press |pages=84–110 }}</ref><ref>{{cite book |last=Mayor |first=Adrienne |year=2005 |title=Fossil Legends of the First Americans |chapter=Chapter&nbsp;1: The northeast: Giants, great bears, and grandfather of the buffalo |publisher=Princeton University Press |pages=32–72}}</ref>

In 1767, [[Peter Collinson (botanist)|Peter Collinson]] credited Irish trader [[George Croghan]] for having sent him and [[Benjamin Franklin]] fossil evidence of the mysterious proboscideans, using them for his studies. He concluded that the peculiar grinders (the molars) were built for herbivorous diets of branches of trees and shrubs as well as other vegetation, a view later followed by Franklin.<ref>{{cite thesis |last=Daiutolo |first=Robert, Jr. |date=October 2015 |title=George Croghan: The life of a conqueror |degree=Ph.D. |series=Graduate Program in History |publisher=[[Rutgers University]] |place=New Brunswick–Piscataway, NJ |url=https://rucore.libraries.rutgers.edu/rutgers-lib/48442/PDF/1/play/ }}</ref><ref>{{cite journal |last=Collinson |first=Peter |year=1767 |title=XLVII.&nbsp;Sequel to the foregoing account of the large fossil teeth |journal=[[Philosophical Transactions of the Royal Society of London]] |volume=57 |url=https://www.biodiversitylibrary.org/item/208064#page/534/mode/1up}}</ref>

In 1768, Scottish anatomist [[William Hunter (anatomist)|William Hunter]] recorded that he and his brother [[John Hunter (surgeon)|John Hunter]] observed that the teeth were not like those of modern elephants. He determined that the "grinders" from Ohio were of a carnivorous animal but believed that the tusks belonged to the same animal. After examining fossils from Franklin and Lord Shelburne, Hunter was convinced that the "''pseudo-elephant''", or "''animal incognitum''" (shortened as "''incognitum''"), was an animal species separate from elephants that might have also been the same as the proboscideans found in Siberia. He concluded his article with the opinion that although regrettable to philosophers, humanity should be thankful to heaven that the animal, if truly carnivorous, was extinct.<ref>{{cite journal |last=Hunter |first=William |year=1768 |title=V.&nbsp;Observations on the bones, commonly supposed to be elephants bones, which have been found near the river Ohio in America |journal=[[Philosophical Transactions of the Royal Society of London]] |volume=58 |pages=34–45 |url=https://www.biodiversitylibrary.org/item/207945#page/60/mode/1up }}</ref>

=== Early American observations ===
[[File:C W Peale - The Exhumation of the Mastadon.jpeg|thumb|The 1806–1808 painting ''The Exhumation of the Mastodon'' by [[Charles Willson Peale]]]] 
In 1785, Reverend Robert Annan wrote an account recalling an event in which workers discovered bones in his farm near the Hudson River in New York in fall of 1780. The workers found four molars in addition to another that was broken and thrown away. They also uncovered bones, including vertebrae that broke shortly thereafter. Annan expressed his confusion at what the animal could be but speculated based on its "grinders" that it was carnivorous in diet. He speculated also that it was probably extinct due to some catastrophe within the globe.<ref>{{cite journal |last=Annan |first=Robert |year=1793 |title=Account of a skeleton of a large animal, found near Hudson's River |journal=Memoirs of the [[American Academy of Arts and Sciences]] |volume=2 |number=1 |pages=160–164 |doi=10.2307/27670792 |jstor=27670792 |bibcode=1793MAAAS...2..160A }}</ref>

American statesman [[Thomas Jefferson]] stated his thoughts on ''[[Notes on the State of Virginia]]'' (published by 1785) that the fossil proboscideans may have been carnivorous, still exist in the northern parts of North America, and are related to mammoths whose remains were found in Siberia. Jefferson referenced the theory of American [[social degeneracy]] by [[Georges-Louis Leclerc, Comte de Buffon]], countering it by using extant and extinct animal measurements, including those of "mammoths," as proof that North America faunas were not "degenerative" in size.<ref>{{cite book|last=Jefferson|first=Thomas|year=1785|title=Notes on the State of Virginia|publisher=Philippe Denis Pierres|pages=42–80|url=https://books.google.com/books?id=DTWttRSMtbYC}}</ref> Semonin pointed out that social degeneracy was an offensive concept to Anglo-American naturalists and that the American proboscidean fossils were used as political tools to inspire [[American nationalism]] and counter against the theory of American degeneracy.<ref name="monster5">{{cite book|last=Semonin|first=Paul|year=2000|title=American Monster: How the nation's first prehistoric creature became a symbol of national identity |chapter=Chapter&nbsp;5: The American ''incognitum'' in Paris |publisher=NYU Press |pages=111–135 }}</ref><ref>{{cite book |last=Semonin |first=Paul |year=2000 |title=American Monster: How the nation's first prehistoric creature became a symbol of national identity |chapter=Chapter&nbsp;11: “Monarch of the wilderness” |publisher=NYU Press |pages=263–287 }}</ref>

[[File:Skeleton Missouri Leviathan Drawing.jpg|thumb|left|Colored [[lithograph]] of the "''Missourium''" (= ''Mammut'') skeleton, {{circa|1845}}]]
In 1799, laborers recovered a thighbone while digging a [[marl]] pit at John Masten's farm in [[Newburgh (town), New York|Newburgh]], New York, and subsequent excavations were observed by a crowd of over a hundred people.<ref name="monster7">{{cite book |last=Semonin |first=Paul |year=2000 |title=American Monster: How the nation's first prehistoric creature became a symbol of national identity |chapter=Chapter&nbsp;13: Exhumation of the monster |publisher=NYU Press |pages=315–340 }}</ref> American painter and exhibitionist [[Charles Willson Peale]] visited the locality in 1801, where he first sketched the fossils then purchased excavation privileges and full ownership of the fossils from Masten and borrowed a loan from the [[American Philosophical Society]] (APS) in [[Philadelphia]], [[Pennsylvania]]. In addition to the first skeleton, the second was excavated using a mill-like device to drain a {{cvt|12|ft}} deep marl pit. Peale assembled a complete skeleton in his [[Peale's Philadelphia Museum|Philadelphia Museum]] in 1804, and its exhibit was open first to invited members of the American Philosophical Society on December&nbsp;24 then to the general public on December&nbsp;25 for an exhibit admission fee in addition to the general admission fee.<ref name="peale">{{cite journal|last=Zygmont|first=Brian J.|year=2015|title=Charles Willson Peale's ''The Exhumation of the Mastodon'' and the great chain of being: The interaction of religion, science, and art in early-federal America |journal=Text Matters |volume=5 |number=5 |pages=95–111 |doi=10.1515/texmat-2015-0008 |hdl=11089/15025 |hdl-access=free }}</ref>

The special exhibition attracted thousands of visitors, and the skeleton became a US national symbol.<ref>{{cite journal |last=Hoffman |first=Sheila K. |year=2018 |title=The origins of Puritan politics in U.S. museums: Nation building and "the arts" from 1776 to 1806 |journal=ICOFOM Study Series |volume=46 |issue=46 |pages=131–145 |doi=10.4000/iss.1025 }}</ref> Charles Peale's son [[Rembrandt Peale]] took the skeleton to Europe used to promote the fossil proboscidean and have it used as support for Jefferson's final rebuttals against Buffon's arguments for supposed inferiority of American faunas. Author Keith Stewart Thomson argued that the promotion of the "mastodon" skeleton made it a symbol of the strength of American nationalism and that "mammoth" as a term became associated with gigantism. Decades later, the museum bankrupted, and the first skeleton's specimens were sold to some German spectators in around 1848, who eventually sold it to [[Hessisches Landesmuseum Darmstadt]] in Germany where it is now displayed. The second skeleton's specimens landed eventually at the [[American Museum of Natural History]].<ref name="peale2">{{cite book|last=Thomson|first=Keith Stewart|year=2008|title=The Legacy of the Mastodon|chapter=Chapter&nbsp;6: Fossils and show business: Mr.&nbsp;Peale’s mastodon |publisher=Yale University Press |pages=46–54 }}</ref>

{{multiple image
 | align = right
 | image1= Burning Tree Mastodon excavation (mid-December 1989), Burning Tree Golf Course, Heath, east-central Ohio.jpg
 | image2= Mammut americanum - Burning Tree Mastodon (Upper Pleistocene, 11.39 ka; Burning Tree Golf Course, south of Heath, southern Licking County, central Ohio, USA) 1 (15276264887).jpg
 | total_width = 400
 | total_height= 400
 | footer = Excavation of a specimen in a [[golf course]] in [[Heath, Ohio]], 1989 (left) and a replica of the "[[Burning Tree mastodon]]" complete skeleton (right)
}}
Other skeletons of ''Mammut americanum'' were excavated within the United States in the first half of the 19th century. One of them was collected by American showman [[Albert C. Koch]] in what is today the [[Mastodon State Historic Site]] at [[Missouri]] in 1839. He hypothesized in 1840 that the proboscidean, which he classified as ''Missourium'', was much larger than an elephant, had horizontal tusks plus trunks, and occupied aquatic habitats.<ref name="koch">{{cite journal|last=McMillan|first=R. Bruce|year=2022|title=Albert C. Koch's Missourium and the debate over the contemporaneity of humans and the Pleistocene megafauna of North America|journal=Earth Sciences History|volume=41|issue=2|pages=410–439|doi=10.17704/1944-6187-41.2.410|bibcode=2022ESHis..41..410M }}</ref> He acquired additional fossils from a spring on the [[Pomme de Terre River (Missouri)|Pomme de&nbsp;Terre River]] to assemble a mounted skeleton of the "''Missouri Leviathan''" and briefly exhibited it at {{nobr|[[St. Louis]].}} After exhibiting the skeleton throughout Europe, he sold the skeleton to the [[British Museum of Natural History]]. [[Richard Owen]] then properly reassembled the skeleton, and it today is on display there.<ref name="koch2">{{cite journal|last=McMillan|first=R. Bruce|year=2010|title=The Discovery of Fossil Vertebrates on Missouri's Western Frontier|journal=Earth Sciences History|volume=29|issue=1|pages=26–51|doi=10.17704/eshi.29.1.j034662534721751|bibcode=2010ESHis..29...26M }}</ref><ref name="osborn"/>

In 1845, another skeleton was excavated from Newburgh by laborers hired by Nathaniel Brewster initially to remove [[lacustrine deposits]] to fertilize the neighboring fields. They were observed by a large amount of spectators and uncovered relatively complete fossil evidence of ''M.&nbsp;americanum''.<ref name="warren3">{{cite book|last=Warren|first=John Collin|year=1852|title=The Mastodon giganteus of North America|section=Discovery of the skeleton|publisher=John Wilson and Son|pages=4–7|url=https://www.biodiversitylibrary.org/item/126175#page/24/mode/1up}}</ref><ref name="AMNH">{{cite journal|last=Horenstein|first=Sidney|year=2008|title=New York City Mastodons: Big Apple Tusks|journal=Evolution: Education and Outreach|volume=1|issue=2 |pages=204–209|doi=10.1007/s12052-008-0042-y|doi-access=free}}</ref> The skeleton was exhibited in [[New York City]] and other New England towns then was acquired by [[John Collins Warren (surgeon, born 1778)|John Collins Warren]] for study.<ref name="warren2">{{cite book|last=Warren|first=John Collin|year=1852|title=The Mastodon giganteus of North America|section=Geological situation and causes of preservation|publisher=John Wilson and Son|pages=154–167|url=https://www.biodiversitylibrary.org/item/126175#page/174/mode/1up}}</ref><ref name="newyork">{{cite book|last1=Hartnagel|first1=Chris Andrew|last2=Bishop|first2=Sherman Chauncey|year=1922|title=The Mastodons, Mammoths and Other Pleistocene Mammals of New York State: Being a Descriptive Record of All Known Occurrences|publisher=University of the State of New York|url=https://books.google.com/books?id=9rxRAQAAIAAJ}}</ref> After Warren's death in 1856, the skeleton was sent to Warren's family but was traded to [[Harvard Medical School]] for John Warren's skeleton. The "Warren mastodon", under the request of American paleontologist [[Henry Fairfield Osborn]], was purchased by the American financier [[J. P. Morgan]] for $30,000 in 1906 and donated to the American Museum of Natural History where it is exhibited today.<ref name="monsterafter">{{cite book|last=Semonin|first=Paul|year=2000|title=American Monster: How the Nation's First Prehistoric Creature Became a Symbol of National Identity|chapter=Afterword: The Myth of Wild Nature|publisher=NYU Press|pages=392–411}}</ref><ref name="AMNH"/>

=== Early taxonomic history ===
[[File:Mastodon HLMD.jpg|thumb|left|''Mammut'' skeleton previously displayed by Charles Peale at his museum, now on display at [[Hessisches Landesmuseum Darmstadt]]]]
In the 1790s, the "''American incognitum''" was subject to research by multiple taxonomists. Scottish writer [[Robert Kerr (writer)|Robert Kerr]] erected the species name ''Elephas americanus'' in 1792 based on fossil tusks and "grinders" from the Big Bone Lick locality. He stated that the tusks were similar to elephants while the molars were completely different because they were covered with enamel and had a double row of high conical [[cusp (anatomy)|cusp]] processes. Kerr was unsure about the taxonomic affinities of the molars and referenced that [[Thomas Pennant]] supposed that they belong to an unknown species within the genus ''[[Elephas]]'', giving the common name "American elephant."<ref>{{cite book|last=Kerr|first=Robert|year=1792|title=The animal kingdom, or zoological system, of the celebrated Sir Charles Linnæus. containing a complete systematic description, arrangement, and nomenclature, of all the known species and varieties of the mammalia, or animals which give suck to their young Class&nbsp;I Mammalia|publisher=Edinburgh|pages=115–117|url=https://www.biodiversitylibrary.org/item/119041#page/169/mode/1up}}</ref>

German naturalist [[Johann Friedrich Blumenbach]] also followed up with more taxonomic descriptions of fossil proboscideans in 1799. The first fossil species, recovered from Germany, was described as belonging to the newly erected species ''Elephas primigenius''? (now known as ''[[Mammuthus primigenius]]''). The second was what he considered to be an unknown "colossal land monster of the prehistoric world," considering it to be the "mammoth." He created the genus ''Mammut'' and erected the species ''Mammut ohioticum'' based on fossil bones dug up from Ohio in North America. He said that the species was distinguished from other animals of the prehistoric world based on the unusual shapes of the large molars. The genus name "Mammut" refers to the German translation for "mammoth."<ref>{{cite book|last=Blumenbach|first=Johann Friedrich|year=1799|title=Handbuch der Naturgeschichte [6. ed.]|publisher=Göttingen|pages=695–698|url=https://www.deutschestextarchiv.de/book/view/blumenbach_naturgeschichte_1799?p=719}}</ref> The naming of the genus ''Mammut'' in 1799 makes it the second or third genus to be recognized with taxonomic authority given that ''[[Megalonyx]]'' had been named the same year.<ref>{{cite journal|last=Hooker|first=Jerry J.|year=2007|title=Bipedal browsing adaptations of the unusual Late Eocene–earliest Oligocene tylopod Anoplotherium (Artiodactyla, Mammalia)|journal=Zoological Journal of the Linnean Society|volume=151|issue=3|pages=609–659|doi=10.1111/j.1096-3642.2007.00352.x|doi-access=free}}</ref>

French naturalist [[Georges Cuvier]] also described known fossil proboscidean species back in 1796, although his account was later published in 1799. He considered that the remains uncovered from Siberia were true "mammoths" that had similar dentitions to extant elephants but had some morphological differences. He mentioned the fossil remains that were brought back by Longueil from Ohio back in 1739 and several researchers from previous decades who noted the unusual molars and thought that they belonged to different animals like hippopotamuses. He followed recognition in the previously established species "''Elephas americanus''" and argued that the species was different from elephants and mammoths and cannot be found amongst living animals due to extinction from [[catastrophism]].<ref>{{cite journal|last=Cuvier|first=Georges|year=1799|title=Mémoire sur les espèces d'éléphans vivantes et fossiles|journal=Mémoires de l'Institut des Sciences et Arts|pages=1–22|url=https://www.biodiversitylibrary.org/page/16303001#page/175/mode/1up}}</ref><ref name="arctic">{{cite journal|last=Froese|first=Duane|year=2014|title=The curious case of the Arctic mastodons|journal=Proceedings of the National Academy of Sciences|volume=111|number=52|pages=18405–18406|doi=10.1073/pnas.1422018112|doi-access=free |pmid=25535342 |pmc=4284541}}</ref>

The proboscidean species was subject to several other species names given by other taxonomists within the earliest 18th century as well as the genus name ''Harpagmotherium'' by the Russian naturalist [[Gotthelf Fischer von Waldheim]] in 1808.<ref name="osborn">{{cite book|last=Osborn|first=Harry Fairfield|year=1936|title=Proboscidea: a monograph of the discovery, evolution, migration and extinction of the mastodonts and elephants of the world|volume=1|publisher=J. Pierpont Morgan Fund by the trustees of the American Museum of Natural History|url=https://www.biodiversitylibrary.org/item/44913#page/1/mode/1up}}</ref>

=== Cuvier's taxonomy ===
[[File:Mammut Mastodonte Skeleton Cuvier 1806.png|thumb|Sketch of the skeleton of ''Mammut'', labeled as "Mastodonte"]]
In 1806, Cuvier wrote multiple extended research articles on fossil proboscideans of Eurasia and the Americas. He stated that the bones that Buffon previously described from North America were not of elephants but another animal that he referred to as the "''mastodonte''," or the "''animal of Ohio''."<ref>{{cite journal|last=Cuvier|first=Georges|year=1806|title=Sur les éléphans vivans et fossiles|journal=Annales du Muséum d'histoire naturelle|volume=8|pages=1–68|url=https://www.biodiversitylibrary.org/item/93165#page/4/mode/1up}}</ref> He reinforced the idea that the extinct "mastodon" was an animal close in relationship to elephants that differed by jaws with large tubercles. He suggested that "mammoth" and "carnivorous elephant" be discontinued as names for the species and that it receive a new genus name instead. Cuvier said that for "''mastodonte''," he derived the name's etymology (compound {{lang|grc|μαστός}} ({{transliteration|grc|mastós}}, "breast") + {{lang|grc|ὀδούς}} ({{transliteration|grc|odoús}}, "tooth") from [[Ancient Greek]] to mean "nipple tooth," since he thought that it expressed the characteristic form of the teeth.<ref>{{cite journal|last=Cuvier|first=Georges|year=1806|title=Sur le grand mastodonte|journal=Annales du Muséum d'histoire naturelle|volume=2|pages=270–312|url=https://www.biodiversitylibrary.org/item/51185#page/312/mode/1up}}</ref>

In 1817, the French naturalist officially established the genus name ''Mastodon'', reaffirming that it is extinct and has left no living descendants. He established that it had an overall body form similar to elephants but had molars more similar to hippopotamuses and pigs that did not serve to grind meat. The first species he erected within ''Mastodon'' was ''Mastodon giganteum'', giving it the informal name "great mastodon" and writing that that it is designated to the Ohio proboscidean with abundant fossil evidence, equal size but greater proportions to modern elephants, and diamond-shaped points of the molars. The naturalist also created the second species name ''Mastodon angustidens'' and gave it the informal name "narrow-toothed mastodon," diagnosing it as having narrower molars, smaller sizes compared to ''M. giganteum'', and range distributions in Europe and South America.<ref name="cuvier1">{{cite book|last=Cuvier|first=Georges|year=1817|title=Le règne animal distribué d'après son organisation : pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée|chapter=Sixié ordre des mammiféres. Les pachydermes|publisher=Chez Déterville|pages=227–245|url=https://www.biodiversitylibrary.org/item/18030#page/269/mode/1up}}</ref> Cuvier also erected several other species of ''Mastodon'' originating from other continents in 1824.<ref name="cuvier2">{{cite book|last=Cuvier|first=Georges|year=1824|title=Recherches sur les ossemens fossiles, où l'on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces|section=Résumé général: Des Animaux dont les caractères ont été indiqués ou rectifiés, ou dont l'Ostéologie a été décrite dans cet ouvrage|volume=5|publisher=G. Dufour and E. d'Ocagne|pages=527–536|url=https://www.biodiversitylibrary.org/item/214698#page/535/mode/1up}}</ref> Despite Cuvier's genus name being younger than multiple other genus names, ''Mastodon'' became the most commonly used genus name for the 19th century.<ref name="mammut">{{cite book|last=Perry Hay|first=Oliver|year=1902|title=Bibliography and catalogue of the fossil vertebrata of North America|publisher=Washington Government Printing Office|pages=707–712|url=https://www.biodiversitylibrary.org/item/59973#page/713/mode/1up}}</ref><ref name="osborn"/>

=== Taxonomic problems ===
[[File:Em - Mammut americanum - 3.jpg|thumb|''M. americanum'' skeleton, [[Natural History Museum, London]]. The skeleton was initially assembled by [[Albert C. Koch]] as "''Missourium''" or "''Leviathan''", both now synonymous with ''Mammut''.]]
"''Mastodon''" was riddled with major taxonomic problems since species now determined as belonging to other proboscidean genera were classified to ''Mastodon'' on the basis of similar dentitions to that of "''Mastodon giganteum''" (= ''Mammut americanum''), effectively making it a [[wastebasket taxon]].<ref name="cuvier1"/><ref name="cuvier2"/><ref>{{cite journal|last1=Mazo|first1=A.V.|last2=van der Made|first2=Jan|year=2012|title=Iberian mastodonts: Geographic and stratigraphic distribution|journal=Quaternary International|volume=255|pages=239–256|doi=10.1016/j.quaint.2011.07.047|bibcode=2012QuInt.255..239M }}</ref> Various fossil proboscidean species were classified into ''Mastodon'' in the 19th century before eventually being reclassified into distinct genera.<ref name="osborn"/> In addition to still-valid species names, several synonymous or dubious species names ultimately belonging to different genera were erected within the Americas as well throughout the 19th century.<ref name="notiomastodon">{{cite journal|last1=Mothé|first1=Dimila|last2=Avilla|first2=Leonardo S.|last3=Cozzuol|first3=Mário|last4=Winck|first4=Gisele R.|year=2012|title=Taxonomic revision of the Quaternary gomphotheres (Mammalia: Proboscidea: Gomphotheriidae) from the South American lowlands|journal=Quaternary International|volume=276–277|pages=2–7|doi=10.1016/j.quaint.2011.05.018|bibcode=2012QuInt.276....2M }}</ref><ref name="rhynchotherium">{{cite journal|last1=Lucas|first1=Spencer G.|last2=Morgan|first2=Gary S.|year=2008|title=Taxonomy of Rhynchotherium (Mammalia, Proboscidea) from the Miocene-Pliocene of North America|journal=New Mexico Museum of Natural History and Science Bulletin|volume=44|pages=71–87|url=https://www.researchgate.net/publication/281863115}}</ref><ref>{{cite journal|last=Dalquest|first=Walter W.|year=1975|title=Vertebrate fossils from the Blanco local fauna of Texas|journal=Occasional Papers of the Museum, Texas Tech University|number=30|pages=1–52|url=https://www.biodiversitylibrary.org/item/241967#page/1/mode/1up}}</ref> Also, many species names erected based on ''M.&nbsp;americanum'' remains were erected. As a result, ''M.&nbsp;americanum'' has many synonymous names. The issue of synonymous species names were especially apparent in the first half of the 19th century.<ref name="osborn"/>

Today, the genera that include species formerly classified into ''Mastodon'' include ''[[Gomphotherium]]'' (''G. angustidens'', ''G. pyrenaicum'', ''G. productum'', ''G. libycum'', ''G. subtapiroideum'', ''G. steinheimense''),<ref>{{cite journal|last1=Wang|first1=Shi-Qi|last2=Duangkrayom|first2=Jaroon|last3=Yang|first3=Xiang-Wen|year=2015|title=Occurrence of the Gomphotherium angustidens group in China, based on a revision of Gomphotherium connexum (Hopwood, 1935) and Gomphotherium shensiensis Chang and Zhai, 1978: continental correlation of Gomphotherium species across the Palearctic|journal=Paläontologische Zeitschrift|volume=89|issue=4 |pages=1073–1086|doi=10.1007/s12542-015-0270-8|bibcode=2015PalZ...89.1073W }}</ref><ref>{{cite journal|last=Göhlich|first=Ursula B.|year=2010|title=The Proboscidea (Mammalia) from the Miocene of Sandelzhausen (southern Germany)|journal=Paläontologische Zeitschrift|volume=84|number=1|pages=163–204|doi=10.1007/s12542-010-0053-1|bibcode=2010PalZ...84..163G }}</ref><ref>{{cite book|last=Sanders|first=William J.|year=2023|title=Evolution and Fossil Record of African Proboscidea|publisher=CRC Press}}</ref>  ''[[Zygolophodon]]'' (''Z. turicensis'', ''Z. proavus''),<ref>{{cite journal|last1=Duangkrayom|first1=Jaroon|last2=Wang|first2=Shi-Qi|last3=Deng|first3=Tao|last4=Jintasakul|first4=Pratueng|year=2016|title=The first Neogene record of Zygolophodon (Mammalia, Proboscidea) in Thailand: implications for the mammutid evolution and dispersal in Southeast Asia|journal=Journal of Paleontology|volume=91|number=1|pages=179–193|doi=10.1017/jpa.2016.143}}</ref><ref name="neogene">{{cite journal|last1=von Koenigswald|first1=Wighart|last2=Wigda|first2=Chris|last3=Göhlich|first3=Ursula B.|year=2023|title=New mammutids (Proboscidea) from the Clarendonian and Hemphillian of Oregon – a survey of Mio-Pliocene mammutids from North America|journal=The Bulletin of the Museum of Natural History of the University of Oregon|volume=30 |number=30|url=https://journals.oregondigital.org/nat_history/article/view/6004}}</ref> ''[[Cuvieronius]]'' (''C. hyodon''),<ref>{{cite journal|last1=Mead|first1=Jim I.|last2=Arroyo-Cabrales|first2=Joaquin|last3=Swift|first3=Sandra L.|year=2019|title=Late Pleistocene Mammuthus and Cuvieronius (proboscidea) from Térapa, Sonora, Mexico|journal=Quaternary Science Reviews|volume=223|doi=10.1016/j.quascirev.2019.105949|bibcode=2019QSRv..22305949M }}</ref> ''[[Stegodon]]'' (''S. elephantoides''),<ref>{{cite journal|last1=Nanda|first1=A.C.|last2=Sehgal|first2=Ramesh Kumar|last3=Chauhan|first3=Parth R.|year=2018|title=Siwalik-age faunas from the Himalayan Foreland Basin of South Asia|journal=Journal of Asian Earth Sciences|volume=162|pages=54–68|doi=10.1016/j.jseaes.2017.10.035|bibcode=2018JAESc.162...54N }}</ref> ''[[Stegolophodon]]'' (''S. latidens'', ''S. cautleyi''),<ref>{{cite journal|last=Rai|first=R.C.|year=2004|title=Fossil elephants from the Indian sub-continent and their tusks: A review|journal=Journal of the Palaeontological Society of India|volume=49|pages=169–188|url=https://palaeontologicalsociety.in/vol49/v8.pdf}}</ref> ''[[Anancus]]'' (''A. avernensis'', ''A. sivalensis'', ''A. perimensis''),<ref>{{cite journal|last1=Hautier|first1=Lionel|last2=Mackaye|first2=Hassane Taisso|last3=Lihoreau|first3=Fabrice|last4=Tassy|first4=Pascal|last5=Vignaud|first5=Patrick|last6=Brunet|first6=Michel|year=2009|title=New material of Anancus kenyensis (proboscidea, mammalia) from Toros-Menalla (Late Miocene, Chad): Contribution to the systematics of African anancines|journal=Journal of African Earth Sciences|volume=53|issue=4–5|pages=171–176|doi=10.1016/j.jafrearsci.2009.01.003|bibcode=2009JAfES..53..171H }}</ref> ''[[Tetralophodon]]'' (''T. longirostris''),<ref>{{cite journal|last1=Wang|first1=Shi-Qi|last2=Saegusa|first2=Haruo|last3=Duangkrayom|first3=Jaroon|last4=He|first4=Wen|last5=Chen|first5=Shan-Qin|year=2017|title=A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China|journal=Palaeoworld|volume=26|issue=4|pages=703–717|doi=10.1016/j.palwor.2017.03.005}}</ref> ''[[Choerolophodon]]'' (''C. pentelici''),<ref>{{cite journal|last1=Konidaris|first1=George|last2=Koufos|first2=George D.|last3=Kostopoulos|first3=Dimitris S.|last4=Merceron|first4=Gildas|year=2016|title=Taxonomy, biostratigraphy and palaeoecology of Choerolophodon (Proboscidea, Mammalia) in the Miocene of SE Europe-SW Asia: Implications for phylogeny and biogeography|journal=Journal of Systematic Palaeontology|volume=14|issue=1|pages=1–27|doi=10.1080/14772019.2014.985339|bibcode=2016JSPal..14....1K }}</ref> ''[[Stegomastodon]]'' (''S. mirificus''),<ref name="stegomastodon">{{cite book|editor-last1=Sullivan|editor-first1=Robert M.|editor-last2=Lucas|editor-first2=Spencer G.|editor-last3=Spielmann|editor-first3=Justin A.|last1=Morgan|first1=Gary S.|last2=Lucas|first2=Spencer G.|year=2011|title=Fossil Record 3|section=Stegomastodon (Mammalia: Proboscidea: Gomphotheriidae) from the Blancan and Irvingtonian (Pliocene and early Pleistocene) of New Mexico|publisher=Bulletin of the New Mexico Museum of Natural History and Science|pages=570–582|url=https://www.researchgate.net/publication/283079006}}</ref> ''[[Rhynchotherium]]'' ("''R.''" ''euhypodon''),<ref name="rhynchotherium"/> ''[[Stenobelodon]]'' (''S. floridanus''),<ref name="stenobelodon">{{cite journal|last=Lambert|first=W. David|year=2023|title=Implications of discoveries of the shovel-tusked gomphothere Konobelodon (Proboscidea, Gomphotheriidae) in Eurasia for the status of Amebelodon with a new genus of shovel-tusked gomphothere, Stenobelodon|journal=Journal of Vertebrate Paleontology|volume=43|issue=1|doi=10.1080/02724634.2023.2252021}}</ref> and ''[[Notiomastodon]]'' (''N. platensis'').<ref name="notiomastodon"/>

In 1830, American naturalist [[John Davidson Godman]] created the genus ''Tetracaulodon'' plus its species ''T. Mastodontoideum'' based on what he determined to be differences between it and ''Mastodon'' based on the skull and dentition.<ref>{{cite journal|last=Godman|first=John Davidson|year=1830|title=Description of a New Genus and New Species of Extinct Mammiferous Quadruped|journal=Transactions of the American Philosophical Society|volume=3|url=https://www.biodiversitylibrary.org/page/24785763#page/532/mode/1up}}</ref> Both [[Richard Harlan]] and [[William Cooper (conchologist)|William Cooper]] pointed out that except for the tusks, all other characteristics of the specimens were consistent with ''M. giganteum''. They therefore argued that there was no reason to assume that the tusks were not just individual variations, a view followed also by [[George William Featherstonhaugh]]. Isaac Hays comparatively defended Godman's taxon, which led to a bitter debate regarding the validity of the genus amongst American naturalists.<ref name="tetracaulodon">{{cite journal|last=Gerstner|first=Patsy A.|year=1970|title=Vertebrate Paleontology, an Early Nineteenth-Century Transatlantic Science|journal=Journal of the History of Biology|volume=3|number=1|pages=137–148|doi=10.1007/BF00569310 |jstor=4330534 |url=https://www.jstor.org/stable/4330534}}</ref>

The validities of both ''Tetracaulodon'' and ''Missourium'' were rejected by Owen in 1842, although he retained the former name informally.<ref>{{cite journal|last=Owen|first=Richard|year=1842|title=Report on the Missourium now exhibiting at the Egyptian Hall|journal=Proceedings of the Geological Society of London|volume=3|number=2|pages=689–695|url=https://www.biodiversitylibrary.org/item/96958#page/717/mode/1up}}</ref> By 1869, American paleontologist [[Joseph Leidy]] determined that ''Mastodon americanus'' is the senior species synonym and listed ''M. giganteum'' as a junior synonym. He also listed ''Mammut'', ''Harpagmotherium'', ''Mastotherium'', ''Missourium'', and ''Leviathan'' as synonyms of ''Mastodon''. He also noted that ''M.&nbsp;americanum'' as a species was highly variable in morphology.<ref>{{cite book|last=Leidy|first=Joseph|year=1869|title=The extinct mammalian fauna of Dakota and Nebraska : Including an account of some allied forms from other localities, together with a synopsis of the mammalian remains of North America|publisher=J.B. Lippincott|url=https://www.biodiversitylibrary.org/item/60918#page/398/mode/1up}}</ref><ref name="utah">{{cite journal|last=Miller|first=Wade E.|year=1987|title=Mammut americanum, Utah's First Record of the American Mastodon|journal=Journal of Paleontology|volume=61|number=1|pages=168–183|doi=10.1017/S0022336000028316 |jstor=1305142 |bibcode=1987JPal...61..168M |url=https://www.jstor.org/stable/1305142}}</ref>

In 1902, American paleontologist [[Oliver Perry Hay]] listed ''Mammut'' as the prioritized genus name given its status as the oldest genus name, making ''Mastodon'', ''Tetracaulodon'', and ''Missourium'' classified as junior synonyms. He also established ''M.&nbsp;americanum'' as the type species.<ref name="mammut"/> The genus name ''Mastodon'' was subsequently abandoned by many American paleontologists in favor of ''Mammut'' within the early 20th century.<ref name="etymology">{{cite journal|last=Palmer|first=Theodore Sherman|year=1904|title=A List of the Genera and Families of Mammals|journal=North American Fauna|issue=23|doi=10.3996/nafa.23.0001 |url=https://www.biodiversitylibrary.org/item/83341#page/405/mode/1up|doi-access=free}}</ref><ref>{{cite journal|last=Lull|first=Richard Swann|year=1908|title=The Evolution of the Elephant|journal=American Journal of Science|series=4|volume=25|issue=147 |pages=169–212|doi=10.2475/ajs.s4-25.147.169 |bibcode=1908AmJS...25..169L |url=https://www.biodiversitylibrary.org/page/40227522#page/193/mode/1up}}</ref><ref>{{cite book|last=Hay|first=Oliver P.|year=1923|title=The Pleistocene of North America and its vertebrated animals from the states east of the Mississippi River and from the Canadian provinces east of longitude 95°|publisher=Carnegie Institution of Washington|number=322|url=https://www.biodiversitylibrary.org/item/66297#page/4/mode/1up}}</ref><ref name="osborn"/> In 1942, American paleontologist [[George Gaylord Simpson]] said that for his study, he prioritized the historic plus taxonomically correct name ''Mammut'' over ''Mastodon''.<ref name="beginnings">{{cite journal|last=Simpson|first=George Gaylord|year=1942|title=The Beginnings of Vertebrate Paleontology in North America|journal=Proceedings of the American Philosophical Society|volume=86|number=1|pages=130–188|jstor=985085 |url=https://www.jstor.org/stable/985085}}</ref> He continued prioritizing ''Mammut'' in 1945, stating that people were generally aware of its taxonomic priorities over ''Mastodon'' and that people had refused to use it. He stated that he did not want to either but reluctantly set aside his personal preferences to follow taxonomic rules.<ref>{{cite book|last=Simpson|first=George Gaylord|year=1945|title=The Principles of Classification and a Classification of Mammals|publisher=Bulletin of the American Museum of Natural History|volume=85|url=https://books.google.com/books?id=28TPAAAAMAAJ}}</ref>

=== Additional species ===
[[File:Pliomastodon Mammut vexillarius skull drawing.png|thumb|left|Sketch of the reconstructed skull of "''Pliomastodon vexillarius''" (= ''Mammut vexillarius''), 1930]]
In 1921, Osborn created the species name ''Mastodon matthewi'' based on distinct molars from the [[Snake Creek Formation]] of western [[Nebraska]], naming it in honor of [[William Diller Matthew]]. He also erected another species ''M. merriami'' from the [[Thousand Creek Formation]] in [[Nevada]], which was eventually synonymized with ''Zygolophodon proavus''.<ref name="matthewi">{{cite journal|last=Osborn|first=Henry Fairfield|year=1921|title=First appearance of the true mastodon in America|journal=American Museum Novitates|number=10|pages=1–6|doi=10.1126/science.54.1388.108 |pmid=17734372 |bibcode=1921Sci....54..108F |url=https://www.biodiversitylibrary.org/page/26890426#page/135/mode/1up}}</ref><ref name="neogene"/> Osborn in 1926 followed up for ''Mastodon matthewi'' by establishing the genus ''Pliomastodon'' for the species based on cranial differences from "''Miomastodon''" (= ''Zygolophodon'').<ref>{{cite journal|last=Osborn|first=Henry Fairfield|year=1926|title=Additional new genera and species of the mastodontoid proboscidea|journal=American Museum Novitates|number=238|pages=1–16|url=https://digitallibrary.amnh.org/items/94c50ee5-2dc1-4788-a440-cd135a90bffe}}</ref>

In 1930, Matthew erected a second species for ''Pliomastodon'' named ''P. vexillarius'' based on fossil material from the locality of [[Elephant Hill (California)|Elephant Hill]] in [[California]], determining that it differs from ''Mammut'' by differences in the skull and that the etymology of the species name was made in honor of paleontological contributions by the [[Standard Oil Company]] of California.<ref name="vexillarius">{{cite journal|last=Matthew|first=William Diller|year=1930|title=A Pliocene mastodon skull from California: Pliomastodon vexillarius n. sp|journal=University of California Publications in Geological Sciences|volume=19|issue=16|pages=336–348}}</ref><ref name="neogene"/>

In 1933, [[Childs Frick]] named the species ''Mastodon raki'' from the locality of [[Truth or Consequences, New Mexico|Truth or Consequences]], [[New Mexico]] based on differences on the [[heel]] and M<sub>3</sub> tooth from ''M.&nbsp;americanus'', otherwise having proportions similar to it.<ref>{{cite journal|last=Frick|first=Childs|year=1933|title=New remains of trilophodont-tetrabelodont mastodonts|journal=Bulletin of the American Museum of Natural History|volume=59|pages=505–652}}</ref><ref name="neogene"/> In 1936, [[Chester Stock]] published the species name ''Pliomastodon nevadanus'' based on fossils from the Thousand Creek Beds of northwestern Nevada.<ref name="nevadanum">{{cite journal|last=Stock|first=Chester|year=1936|title=A Pliomastodon skull from the Thousand Creek beds, northwestern Nevada|journal=Contributions to Palaeontology|volume=3|number=473|pages=35–39|url=https://www.biodiversitylibrary.org/item/322843#page/57/mode/1up}}</ref> In 1937, John R. Schultz created the species name ''Pliomastodon? cosoensis'', naming it after the [[Coso Range|Coso Mountains]] in [[Inyo County]], California where skull fossils were recovered.<ref name="cosoensis">{{cite journal|last=Schultz|first=John R.|year=1937|title=A late Cenozoic vertebrate fauna from the Coso Mountains, Inyo County, California|journal=Carnegie Institution of Washington Publications|pages=77–109|url=https://www.biodiversitylibrary.org/item/322907#page/95/mode/1up}}</ref>

In 1963, J. Arnold Shotwell and Donald E. Russell created another species ''Mammut (Pliomastodon) furlongi'', assigning it to fossils collected from the [[Juntura Formation]] of Oregon. The species name was created in honor of [[Eustace L. Furlong]], who made early fossil collections from the western side of the Juntura Basin.<ref name="furlongi">{{cite journal|last1=Shotwell|first1=J. Arnold|last2=Russell|first2=Donald E.|year=1963|title=Mammalian fauna of the upper Juntura Formation, the Black Butte local fauna|journal=Transactions of the American Philosophical Society|volume=53|pages=42–69}}</ref>

The genus ''Pliomastodon'' was synonymized with ''Mammut'' while ''Miomastodon'' was synonymized with ''Zygolophodon'' by [[Jeheskel Shoshani]] and [[Pascal Tassy]] in a 1996 appendix,<ref>{{cite book|editor-last1=Shoshani|editor-first1=Jeheskel|editor-last2=Tassy|editor-first2=Pascal|year=1996|title=The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives|section=Appendix B|publisher=Oxford University Press|pages=352–353|isbn=978-0-19-854652-8}}</ref> a view that was followed by other authors in later years.<ref name="tertiary">{{cite book|editor-last1=Janis|editor-first1=Christine M.|editor-last2=Scott|editor-first2=Kathleen M.|editor-last3=Jacobs|editor-first3=Louis L.|last1=Lambert|first1=W. David|last2=Shoshani|first2=Jeheskel|year=1998|title=Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate like Mammals|section=Proboscidea|publisher=Cambridge University Press, New York|pages=606–621}}</ref><ref name="pacificum">{{cite journal|last1=Dooley Jr.|first1=Alton C.|last2=Scott|first2=Eric|last3=Green|first3=Jeremy|last4=Springer|first4=Kathleen B.|last5=Dooley|first5=Brett S.|last6=Smith|first6=Gregory James|year=2019|title=Mammut pacificus sp. nov., a newly recognized species of mastodon from the Pleistocene of western North America|journal=PeerJ|volume=7|pages=e6614 |doi=10.7717/peerj.6614|doi-access=free|pmid=30944777 |pmc=6441323 }}</ref><ref name="neogene"/>

In 2019, Alton C. Dooley Jr. et al. established ''Mammut pacificus'' based on fossils collected from the [[Diamond Valley Lake]] in [[Hemet, California|Hemet]], California. They also stated that ''M. oregonense'' is a ''[[nomen dubium]]'' and that further analysis needs to be done to confirm whether or not ''M. furlongi'' belongs to ''Zygolophodon'' instead.<ref name="pacificum"/>

In 2023, Wighart von Koenigswald et al. reviewed the North American species of ''Zygolophodon'' and ''Mammut''. They synonymized ''P. adamsi'' and ''P. sellardsi'' with ''Mammut matthewi'' and emended ''M. nevadanus'' and ''M. pacificus'' to ''M. nevadanum'' and ''M. pacificum'', respectively. They also said that they were uncertain of the taxonomic status of ''M. furlongi'', specifically whether or not it was a variant of [[sexual dimorphism]] of ''Z. proavus''. Some authors have considered ''M. nevadanum'' to be synonymous with ''M. matthewi'' while others had retained validity of the species name.<ref name="neogene"/><ref name="pacificum"/>

Several mammutid species outside of North America are classified to ''Mammut'' (or "''Pliomastodon''"), namely ''M. borsoni'', ''M. obliquelophus'', ''M. zhupengensis'', and ''M. lufugense'' (possibly synonymous with ''M. obliquelophus'').<ref name="borsoni">{{cite journal|last1=von Koenigswald|first1=Wighart|last2=Březina|first2=Jakub|last3=Werneburg|first3=Ralf|last4=Göhlich|first4=Ursula B.|year=2022|title=A partial skeleton of "Mammut" borsoni (Proboscidea, Mammalia) from the Pliocene of Kaltensundheim (Germany)|journal=Palaeontologia Electronica|number=25.1.a10|doi=10.26879/1188|doi-access=free}}</ref><ref name="obliquelophus">{{cite journal|last1=Yaghoubi|first1=Sadaf|last2=Ashouri|first2=Ali Reza|last3=Ataabadi|first3=Majid Mirzaie|last4=Ghaderi|first4=Abbas|year=2023|title=First true mastodon from the Late Miocene of Western Asia|journal=Research Square|doi=10.21203/rs.3.rs-3046011/v1}}</ref><ref>{{cite journal|last1=Shiqi|first1=Wang|last2=Chun-Xiao|first2=Li|last3=Xiao-Xiao|first3=Zhang|year=2021|title=On the scientific names of mastodont taxa: nomenclature, Chinese translation, and taxonomic problems|journal=Vertebrata PalAsiatica|volume=59|issue=4|pages=295–332|doi=10.19615/j.cnki.2096-9899.210728}}</ref><ref>{{cite journal|last=Wang|first=Shiqi|year=2023|title=中国新近纪大型植食性哺乳动物演化和生物地层|journal=Quaternary Studies|volume=43|number=3|pages=637–672|doi=10.11928/j.issn.1001-7410.2023.03.01}}</ref> Recent research such as that of von Koenigswald et al. in 2023 warned that the genus ''Mammut'' should be carefully used for non-North American species.<ref name="neogene"/>

=== Classification and evolution ===
[[File:Johann Friedrich Blumenbach.jpg|thumb|left|Portrait of [[Johann Friedrich Blumenbach]], who erected the genus ''Mammut'' in 1799]]
''Mammut'' is the [[type genus]] of the [[Mammutidae]], the sole family of the [[elephantimorph]] clade [[Mammutida]] (the other elephantimorph clade is [[Elephantida]]). The Mammutidae is characterized by molars with zygodont-form crests, which have remained morphologically conservative throughout the evolutionary history of the family. ''Mammut'' is considered to be a derived genus of the family because of strong zygodont development.<ref name="greece">{{cite book|editor-last=Vlachos|editor-first=Evangelos|last1=Konidaris|first1=George E.|last2=Tsoukala|first2=Evangelia|year=2021|title=Fossil Vertebrates of Greece Vol. 1: Basal vertebrates, Amphibians, Reptiles, Afrotherians, Glires, and Primates|chapter=The Fossil Record of the Neogene Proboscidea (Mammalia) in Greece|publisher=Springer Cham|volume=1|pages=299–344|doi=10.1007/978-3-030-68398-6_12|isbn=978-3-030-68397-9 }}</ref> As a family of the Elephantimorpha clade, it is only distantly related to the [[Deinotheriidae]] due to major differences in dentition and emergence of adult teeth.<ref name="sanders"/> The Mammutidae is identified as a [[monophyletic]] clade, meaning that it did not leave any derived descendant groups in its evolutionary history.<ref>{{cite journal|last1=Shi-Qi|first1=Wang|last2=Yu|first2=Li|last3=Duangkrayom|first3=Jaroon|last4=Shao-Kun|first4=Chen|last5=Wen|first5=He|last6=Shan-Qui|first6=Shen|year=2017|title=Early Mammut from the Upper Miocene of northern China, and its implications for the evolution and differentiation of Mammutidae|journal=Vertebrata PalAsiatica|volume=55|issue=3|pages=233–256|url=https://chinaxiv.org/user/view.htm?uuid=ea7f7df31b0a4d62a991311874964ed9&filetype=pdf}}</ref> The monophyly of the Mammutidae makes it differ from the Elephantida, where the [[Gomphotheriidae]] is [[paraphyletic]] (or ancestral to more derived descendant groups in the cladistic sense) in relation to the derived [[elephantoid]] families [[Stegodontidae]] and [[Elephantidae]] (elephants, mammoths, and relatives).<ref>{{cite journal|last1=Mothé|first1=Dimila|last2=Avilla|first2=Leonardo S.|last3=Cozzuol|first3=Mario A.|year=2012|title=The South American Gomphotheres (Mammalia, Proboscidea, Gomphotheriidae): Taxonomy, Phylogeny, and Biogeography|journal=Journal of Mammalian Evolution|volume=20|pages=23–32|doi=10.1007/s10914-012-9192-3}}</ref>

Although the separation of the Mammutida and Elephantida is strongly supported based on morphological differences, their origins within the late [[Paleogene]] remain uncertain. One hypothesis asserts that the Elephantimorpha is monophyletic if the primitive [[Elephantiformes]] genus ''[[Phiomia]]'' was truly ancestral to both the Elephantida and Mammutida. An alternate hypothesis suggests that the Elephantimorpha is diphyletic because ''Phiomia'' is ancestral to gomphotheres while ''[[Palaeomastodon]]'' is ancestral to mammutids.<ref name="sanders">{{cite book|last=Sanders|first=William J.|year=2023|title=Evolution and Fossil Record of African Proboscidea|chapter=Chapter 1: Context of African Proboscidean Evolution|publisher=CRC Press|pages=1–17|doi=10.1201/b20016-1}}</ref> The earliest undisputed mammutid genus ''[[Losodokodon]]'' is recorded in [[Kenya]], Africa and firmly establishes the earliest presence of mammutids in the late [[Oligocene]] (~27-24 Ma). The Mammutidae, like other Paleogene proboscideans, was therefore an endemic radiation within the continent akin to other endemic mammals like [[arsinoithere]]s, [[hyracoid]]s, and [[catarrhine]] [[primates]] plus non-endemics such as [[anthracothere]]s and [[hyaenodont]]s.<ref>{{cite book|last=Sanders|first=William J.|year=2023|title=Evolution and Fossil Record of African Proboscidea|chapter=Chapter 3:Late Paleogene: First Major Diversification and Adaptive Radiation of Proboscideans|publisher=CRC Press|pages=45–99|doi=10.1201/b20016-3}}</ref>

In the early [[Neogene]] phase of evolution, ''[[Eozygodon]]'' made an appearance in the earliest [[Miocene]] (~23-20 Ma) of Africa after ''Losodokodon''. ''Eozygodon'' was subsequently succeeded by ''Zygolophodon'' by the early Miocene, and the latter dispersed into Eurasia by around 19-18 million years ago, and into North America by the middle Miocene. The dispersal of mammutids between Africa and Eurasia may have occurred multiple times. The Mammutidae eventually went extinct in Africa prior to the late Miocene.<ref>{{cite book|last=Sanders|first=William J.|year=2023|title=Evolution and Fossil Record of African Proboscidea|chapter=Chapter 3: Early and Middle Miocene Diversification of Proboscideans and Dominance of Elephantimorphs|publisher=CRC Press|pages=101–148|doi=10.1201/b20016-4}}</ref><ref>{{cite journal|last1=Jiangzuo|first1=Qigao|last2=Wang|first2=Shi-Qi|year=2023|title=Northeastern Asia humidification at the end of the Miocene drives the boost of mammalian dispersals from the Old to New World|journal=Journal of Palaeogeography|volume=12|issue=1|pages=50–68|doi=10.1016/j.jop.2022.09.002|doi-access=free|bibcode=2023JPalG..12...50J }}</ref><ref name="borsoni" />

''Mammut'' as currently defined ''sensu lato'' (in a broad sense) is most likely [[polyphyletic]] (comprising several unrelated groups). This is because the inclusion of Eurasian mammutid species into ''Mammut'' implies that they share a common origin with North American ''Mammut'', but this relationship has been doubted. As a result, these Eurasian species may belong to either other existing mammutid genera or entirely new genera. ''[["Mammut" borsoni]],'' the last Eurasian mammutid, became extinct during the earliest [[Pleistocene]], around 2.5-2&nbsp;million years ago.<ref name="borsoni" />

[[File:Mastodon mother & child.jpg|thumb|Skeletons of an adult and calf ''M.&nbsp;americanum'', [[La Brea Tar Pits|George C. Page Museum]]]] 
The oldest evidence of mammutids in North America is of a fragmentary molar of ''Zygolophodon'' sp. from [[Massacre Lake]], Nevada, dating to 16.5-16.4&nbsp;Ma (during the [[Hemingfordian]] stage of the [[North American land mammal age]]s (NALMA)). The only definitively defined species of ''Zygolophodon'' from North America is ''Z.&nbsp;proavus'', which occurs in the [[Barstovian]] and [[Clarendonian]] stages. ''M? furlongi'' from the Black Butte in Oregon also dates back to the Clarendonian stage, but the affinities of the species remains unclear. If it truly is a species of ''Mammut'', then its earliest temporal range is recorded at about 10&nbsp;Ma. The earliest undisputed appearance of ''Mammut'' is of ''M.&nbsp;nevadanum'' from Thousand Creek Beds, dating back to the early [[Hemphillian]], or 8.0-7.1&nbsp;Ma. Historically, North American paleontologists considered that North American ''Zygolophodon'' evolved into ''Mammut'' in an endemic fashion while European workers generally thought that ''Mammut'' was a Eurasian immigrant that replaced North American ''Zygolophodon'' during the Miocene or [[Pliocene]]. Current evidence supports an endemic origin of North American ''Mammut'' from ''Zygolophodon'' without later migration because of the gradual appearance of ''Mammut'' morphologies and a lack of solid evidence that ''Mammut'' ''sensu stricto'' (in a strict sense) ever dispersed outside of North America.<ref name="neogene"/>

''M. matthewi'' is recorded from the late Hemphillian to early [[Blancan]] stages. Mammutid specimens of the Hemphillian and Blancan had typically previously been assigned to ''M.&nbsp;matthewi'', but this is seemingly the result of overreliance on stratigraphic positions to define taxa. ''M.&nbsp;vexillarius'', ''M.&nbsp;raki'', and ''M.&nbsp;cosoensis'' are definitively recorded from the Blancan, and ''M.&nbsp;raki'' specifically is thought to not be synonymous with ''M.&nbsp;pacificum''.<ref name="neogene"/> ''M.&nbsp;americanum'' (known popularly as an "American mastodon" or simply "mastodon") is also stratigraphically recorded first from the early Blancan of the [[Ringold Formation]], [[Washington (state)|Washington]]. The age of the formation where the mammutid specimen was found dates to about 3.75&nbsp;Ma. It is also known from multiple other Blancan sites such as Fish Springs Flat in Nevada.<ref name="neogene"/><ref>{{cite journal|last=Pasenko|first=Michael|year=2011|title=A Specimen of Mammut americanum (Proboscidea, Mammalia) from Yavapai County, West-Central Arizona|journal=Journal of the Arizona-Nevada Academy of Science|volume=42|issue=2|pages=61–64|doi=10.2181/036.042.0201}}</ref><ref>{{cite thesis |last=Ruez |first=Dennis Russell, Jr. |year=2007 |title=Effects of climate change on mammalian fauna composition and structure during the advent of North American continental glaciation in the Pliocene |publisher=[[University of Texas at Austin|University of Texas]] |place=Austin, TX |url=https://www.proquest.com/docview/304831808|id={{ProQuest|304831808}} }}</ref> From the [[Irvingtonian]] to the [[Rancholabrean]] (from around 1.6&nbsp;million to 11,000&nbsp;years ago), only ''M.&nbsp;americanum'' and the newly appearing ''M.&nbsp;pacificum'' are recorded, the former having an exceptional level of diversity based on abundant skeletal evidences from the late Pleistocene that is unusual for the typical mammutid fossil record.<ref name="pacificum"/><ref name="neogene"/>

The following cladogram defines the phylogeny of certain proboscideans, a majority known from [[endocasts]], including ''M.&nbsp;americanum'':<ref name="endocast">{{cite book |editor1-last=Dozo |editor1-first=María Teresa |editor2-last=Paulina-Carabajal |editor2-first=Ariana|editor3-last=Macrini|editor3-first=Thomas E. |editor4-last=Walsh |editor4-first=Stig |last1=Benoit|first1=Julien|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 |display-authors=6 |year=2022 |title=Paleoneurology of Amniotes: New directions in the study of fossil endocasts |chapter=Paleoneurology of the Proboscidea (Mammalia, Afrotheria): Insights from their brain endocast and labyrinth |publisher=Springer Cham |pages=579–644 |doi=10.1007/978-3-031-13983-3_15 |isbn=978-3-031-13982-6 |chapter-url=https://hal.umontpellier.fr/hal-04295685/file/Benoit-et-al-TEM.pdf }}</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]]&nbsp;
                     |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]]
                                    }}
                                 }}
                              }}
                           }}
                        }}
                     }}
                  }}
               }}
            }}
         }}
      }}
   }}
}}

== Description ==
=== Skull ===
{{multiple image
 | align = right
 | image1= Mastodon skull 3-26-14 116.jpg
 | image2= Mammut pacificus holotype skull Dooley et al 2019.png
 | total_width = 400
 | total_height= 400
 | footer = Articulated ''M.&nbsp;americanum'' skull at the [[Porter County Museum]] (left) and an unarticulated [[cranium]] plus tusks of ''M.&nbsp;pacificum'' (right)
}}
''Mammut'' is diagnosed and differentiated in terms of the skull from ''Zygolophodon'' as having a shortened bottom skull base (basicranium) and a high-domed [[cranium]]. It is also diagnosed as having an "elephantoid" [[mandible]] with a shortened [[mandibular symphysis]] (or "brevirostrine") and a protruding angular process in the mandible. The diagnosis accounts for both true ''Mammut'' species and ''Mammut'' species pending reassessments.<ref name="tobien">{{cite book|editor-last1=Shoshani|editor-first1=Jeheskel|editor-last2=Tassy|editor-first2=Pascal|last=Tobien|first=Heinz|year=1996|title=The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives|chapter=Chapter 9: Evolution of zygodons with emphasis on dentition|publisher=Oxford University Press|pages=76–85|doi=10.1093/oso/9780198546528.003.0009|isbn=978-0-19-854652-8}}</ref><ref>{{cite journal|last1=Konidaris|first1=George E.|last2=Aytek|first2=Ahmet I.|last3=Yavuz|first3=Alper Y.|last4=Tarhan|first4=Erhan|last5=Alçiçek|first5=M. Cihat|year=2023|title=First Report of "Mammut" (Mammalia, Proboscidea) from the Upper Miocene of Turkey|journal=Journal of Vertebrate Paleontology|volume=42|issue=6|doi=10.1080/02724634.2023.2222784}}</ref> The shortening of the symphysis is one of the major evolutionary trends observed in Neogene mammutids, making it critical in understanding the evolutionary transition from ''Zygolophodon'' to ''Mammut''. However, mandibular remains with characteristics of ''Mammut'' are not known from any anywhere within the Hemphillian, thus making the transition poorly understood.<ref name="neogene"/> It differs from ''[[Sinomammut]]'' by the shortened mandibular symphysis, although ''Mammut'' sometimes retained lower tusks unlike the other genus.<ref>{{cite journal|last1=Mothé|first1=Dimila|last2=Avilla|first2=Leonardo dos Santos|last3=Zhao|first3=Desi|last4=Xie|first4=Guangpu|last5=Sun|first5=Boyang|year=2016|title=A new Mammutidae (Proboscidea, Mammalia) from the Late Miocene of Gansu Province, China|journal=Anais da Academia Brasileira de Ciências|volume=88|issue=1 |pages=65–74|doi=10.1590/0001-3765201520150261|pmid=26839998 }}</ref>

''M. americanum'' is diagnosed as having a long plus low skull and a shortened mandible.<ref>{{cite journal|last1=Bravo-Cuevas|first1=Victor M.|last2=Morales-García|first2=Nuria M.|last3=Cabral-Perdomo|first3=Miguel A.|year=2015|title=Description of mastodons (Mammut americanum) from the late Pleistocene of southeastern Hidalgo, central Mexico|journal=Boletín de la Sociedad Geológica Mexicana|volume=67|number=2|pages=337–347 |doi=10.18268/BSGM2015v67n2a14|doi-access=free}}</ref> The [[frontal bone]] (or forehead) gives off a flattened appearance compared to extant elephants.<ref>{{cite journal|last1=Knox|first1=S. Cragin|last2=Pitts|first2=Sue|year=1984|title=Excavation of a Mastodon at Vicksburg, Mississippi|journal=Mississippi Geology|volume=4|number=4|pages=1–12|url=https://geology.deq.ms.gov/Publications/Mississippi_Geology/Vol_4_4.pdf}}</ref> The skull of ''M. americanum'' has many [[plesiomorphies]] (or ancestral traits) that can be observed, namely the low and flat brain case, a slightly vertical basicranium, a narrow nasal aperture inlet of the nose with no step-like perinasal fossa, and a backside [[infraorbital foramen]]. At least some of these features are thought to have been acquired from ''Phiomia''. The nasal aperture of ''M.&nbsp;americanum'' is oval, whereas that of the skull of "''M.''" cf. ''obliquelophus'' is more trapezoidal. ''M.&nbsp;americanum'' is also more derived based on the lack of a strong proximal constriction of the incisive fossa of the [[incisive foramen]].<ref>{{cite journal|last1=Shi-Qi|first1=Wang|last2=Yu|first2=Li|last3=Duangkrayom|first3=Jaroon|last4=Shao-Kun|first4=Chen|last5=Wen|first5=He|last6=Shan-Qin|first6=Chen|year=2017|title=Early Mammut from the Upper Miocene of northern China, and its implications for the evolution and differentiation of Mammutidae|journal=Vertebrata PalAsiatica|volume=55|issue=3|pages=233–256|url=https://www.researchgate.net/publication/318588129}}</ref> ''M. americanum'' also has a high and narrow [[orbit (anatomy)|orbit]] with a somewhat rectangular outline, but it is less rectangular than that of ''Eozygodon''. The North American mammutid retains a primitive trait in the form of the orbit containing a [[lacrimal bone]] with a hole known as the lacrimal foramen. Unlike elephantidans, it has another primitive trait of a short and high-positioned [[temporal fossa]], a trait shared with ''Eozygodon''.<ref>{{cite journal|last=Tassy|first=Pascal|year=2018|title=Remarks on the cranium of Eozygodon morotoensis (Proboscidea, Mammalia) from the early Miocene of Africa, and the question of the monophyly of Elephantimorpha|journal=Revue de Paléobiologie, Genève|volume=37|issue=2|pages=593–607|url=http://institutions.ville-geneve.ch/fileadmin/user_upload/mhn/documents/Museum/Revue_de_Paleo/593-607_Tassy.pdf}}</ref>

=== Endocast anatomy ===
[[File:Mastodon Mammut americanum brain endocast.png|upright=0.85|thumb|left|Illustration of the [[endocast]] of ''M.&nbsp;americanum'' without any visible [[olfactory bulb]]s, 1906]]
''M.&nbsp;americanum'' is known by several brain endocasts stored in American museums, although they are seldom subjected to studies. In 1973, neuroscientist Harry J. Jerison studied an endocast of ''Mammut'', recording that it was elephantlike in both size and shape.<ref>{{cite book|last=Jerison|first=Harry J.|year=1973|title=Evolution of the Brain and Intelligence |chapter=Chapter&nbsp;15: Special topics |publisher=Elsevier|pages=340–362|isbn=978-0-323-14108-6 |url=https://books.google.com/books?id=20tlZXXWX-MC}}</ref> According to Shoshani et al. in 2006, the endocast of ''M.&nbsp;americanum'' features the [[olfactory bulb]]s protruding in front of the [[frontal lobe]]. They also drew several proboscidean brains to scale, in which the brain of ''M.&nbsp;americanum'' was much larger than that of ''[[Moeritherium]] lyonsi'' but smaller than that of the [[Asian elephant]] (''Elephas maximus'').<ref>{{cite journal |last1=Shoshani |first1=Jeheskel |last2=Kupsky |first2=William J. |last3=Marchant|first3=Gary H. |year=2006 |title=Elephant brain: Part&nbsp;I: Gross morphology, functions, comparative anatomy, and evolution |journal=Brain Research Bulletin|volume=70|issue=2|pages=124–157|doi=10.1016/j.brainresbull.2006.03.016|pmid=16782503 }}</ref>

Julien Benoit et al. in 2022 explained that while the front tips of the olfactory bulbs of "''M.''"&nbsp;''borsoni'' are partially visible in the brain's back (or dorsal) area, its visibility in ''M.&nbsp;americanum'' is debated. Some authors had argued that the olfactory bulbs are visible in the brain's back area while some other authors did not portray them as being visible. The researchers confirmed based on one specimen that the olfactory bulbs are only partially visible in the brain's back area. They also observed that "''M.''"&nbsp;''borsoni'', despite weighing twice as much as ''M.&nbsp;americanum'', had a 30% lower [[encephalization quotient]] (EQ) compared to the other mammutid species, supporting the idea that the evolution of proboscidean encephalization is tied with phylogeny.<ref name="endocast"/> The Mammutida, as the most basal clade of the Elephantimorpha, has an EQ twice that of ''Moeritherium'' and ''Palaeomastodon''. The endocast volume and brain size of the brain ''M.&nbsp;americanum'' are larger than those of ''Stegodon'' but smaller than those of derived elephantids. It has an EQ that is higher than those of Paleogene proboscideans and "''M.''"&nbsp;''borsoni'' but lower than those of elephantids (extant and extinct) and stegodonts.<ref>{{cite journal|last1=Benoit|first1=Julien|last2=Legendre|first2=Lucas J.|last3=Tabuce|first3=Rodolphe|last4=Obada|first4=Theodor|last5=Mararescul|first5=Vladislav|last6=Manger|first6=Paul|year=2019|title=Brain evolution in Proboscidea (Mammalia, Afrotheria) across the Cenozoic|journal=Scientific Reports|volume=9|number=9323|page=9323 |doi=10.1038/s41598-019-45888-4|pmid=31249366 |pmc=6597534|bibcode=2019NatSR...9.9323B }}</ref>

The type species is also known from endocasts of [[Petrous part of the temporal bone|ear petrosals]].<ref name="endocast"/> According to Eric G. Ekdale, the ear petrosals of ''Mammut'' cannot automatically be distinguished from ''Mammuthus'' alone. The [[subarcuate fossa]] is absent from the cerebellar surface of the inner ear. The ear petrosals of ''Mammut'' are relatively incomplete, leaving several traits to be unable to be observed.<ref>{{cite thesis|last=Ekdale|first=Eric Gregory|year=2009|title=Variation within the bony labyrinth of mammals|publisher=University of Texas at Austin|url=https://www.researchgate.net/publication/44794693}}</ref><ref>{{cite journal|last=Ekdale|first=Eric Gregory|year=2011|title=Morphological variation in the ear region of pleistocene elephantimorpha (Mammalia, Proboscidea) from central Texas|journal=Journal of Morphology|volume=272|issue=4|pages=452–464|doi=10.1002/jmor.10924|pmid=21284018 }}</ref>

=== Dentition ===
[[File:Aurora Mastodon Lower Jaw and Tooth.jpg|thumb|''M.&nbsp;americanum'' lower jaw and molars, [[Phillips Park (Aurora, Illinois)]]]]
[[File:American Mastodon (Mammut americanum) (cropped).jpg|thumb|253x253px|Front view of the "Warren mastodon" (''M.&nbsp;americanum''). Note the presence of a single vestigial mandibular tusk.]]
The family Mammutidae is defined by zygolophodont molars with compressed and sharp transverse ridges plus lack of accessory conules (smaller cusps). The intermediate molars, or the first two molars, are consistently trilophodont, or three-cusped. The dental morphologies of the clade Mammutida contrast strongly with most members of both the Elephantida ([[bunodont]] molars that evolutionarily convert to being thin and platelike) and the Deinotheriidae ([[tapir]]-like [[lophodont]] to bilophodont molars).<ref name="greece"/> The zygodont morphologies of the molars of mammutids were conservative, meaning that they hardly changed in the evolutionary history of the family.<ref name="neogene"/> Mammutids also exhibited evidences of horizontal tooth displacement where milk teeth were gradually replaced by permanent molars, mirroring elephantidans in an instance of [[parallel evolution]].<ref>{{cite journal|last=Sanders|first=William J.|year=2017|title=Horizontal tooth displacement and premolar occurrence in elephants and other elephantiform proboscideans|journal=Historical Biology|volume=30 |issue=1–2|pages=137–156|doi=10.1080/08912963.2017.1297436|bibcode=2018HBio...30..137S }}</ref> The Mammutidae was not the only proboscidean family to have acquired zygodont crested molars, as Neogene species of the gomphothere ''[[Sinomastodon]]'' display moderate to weak zygodont crests. Pleistocene species of ''Sinomastodon'' do not display zygodont crests, however.<ref>{{cite journal|last1=Parray|first1=Khursheed A.|last2=Jukar|first2=Advait M.|last3=Paul|first3=Abdul Qayoom|last4=Ahmad|first4=Ishfaq|last5=Patnaik|first5=Rajeev|year=2022|title=A gomphothere (Mammalia, Proboscidea) from the Quaternary of the Kashmir valley, India|journal=Papers in Palaeontology|volume=8|issue=2|doi=10.1002/spp2.1427|bibcode=2022PPal....8E1427P }}</ref>

The dentition of ''Mammut'' is diagnosed as being strongly zygodont and having no conules. The lophs extend to the long axis of the molars. The first two molars in the dental row have no more than three lophs while the third molars have four lophs plus a [[cingulum (tooth)|cingulum]]. The upper tusks (or upper [[incisor]]s) of ''Mammut'' differ from those of ''Zygolophodon'' by the generally larger sizes, tendency to either straighten or curve up, and the typical lack of any enamel band, although ''M.&nbsp;vexillarius'' retains a very narrow strip of enamel in the upper tusks. The lower (or mandibular) tusks tend to be reduced in comparison. ''M. nevadanum'' represents the earliest case of a North American mammutid species without any enamel band, although the possibility of it being worn off by wear cannot automatically be eliminated.<ref name="tobien"/><ref name="neogene"/> It differs from ''M.&nbsp;americanum'' and ''M.&nbsp;pacificum'' by the nearly straight but downward-facing upper tusk, whereas males of the latter two species have large and upward-facing upper tusks while females had upward or straight but frontward-directed upper tusks.<ref name="pacificum"/> The reduction to loss of the lower tusks plus reduction of the mandibular symphysis of the derived Mammutidae and Elephantida is an instance of [[convergent evolution]], correlating potentially with the need to reduce heat loss due to the decrease of global temperature and humidity during the late Miocene and Pliocene.<ref name="endocast"/> Despite the reductions of the lower tusks, they were still present in Neogene species of ''Mammut''. Pleistocene ''M.&nbsp;americanum'' comparatively often lacks mandibular tusks, and ''M.&nbsp;pacificum'' is always devoid of them.<ref name="neogene"/> The presence of lower tusks in ''M.&nbsp;raki'' separates it as a species from ''M.&nbsp;pacificum''. ''M.&nbsp;pacificum'' differs from ''M.&nbsp;americanum'' in part by the narrower molars. Both species have broader molars compared to the "narrow-toothed" ''M.&nbsp;nevadanum'', ''M.&nbsp;raki'', and ''M.&nbsp;cosoensis''.<ref name="pacificum"/>

Like its relative "''M.''"&nbsp;''borsoni'', ''M.&nbsp;americanum'' had very large tusks, with some records suggesting lengths of {{cvt|3|m}} and diameters exceeding {{cvt|200|mm}} were not unusual.<ref>{{cite journal|last=Larramendi|first=Asier|year=2023|title=Estimating tusk masses in proboscideans: a comprehensive analysis and predictive model|journal=Historical Biology|pages=1–14|doi=10.1080/08912963.2023.2286272}}</ref> In the skull of the earlier-appearing ''M.&nbsp;matthewi'', its [[dental alveolus]] of the right tusk from the locality of [[Hermiston]], Oregon suggests a tusk diameter of approximately {{cvt|200|mm}}.<ref name="neogene"/> Similar to modern elephants, ''M.&nbsp;americanum'' also has degrees of sexual dimorphism indicated by the sizes of the upper tusks. Adult males have tusks 1.15–1.25&nbsp;times as large as those of adult females, also reflecting general body size differences between the two sexes. The sizes of the tusk also depend on the ages of the individuals, as older individuals have larger tusk circumferences than younger ones. Adult individuals of comparable ages have similar tusk sizes, but older individuals do not necessarily have larger tusk sizes. Tusk sizes may have depended on external factors like nutritional stress, geographic location, and reproductive status.<ref>{{cite journal|last1=Smith|first1=Kathlyn M.|last2=Fisher|first2=Daniel C.|year=2011|title=Sexual dimorphism of structures showing indeterminate growth: tusks of American mastodons (Mammut americanum)|journal=Paleobiology|volume=37|issue=2|pages=175–194|doi=10.1666/09033.1|bibcode=2011Pbio...37..175S }}</ref> The tusks of ''M.&nbsp;pacificum'' are thought to have been smaller in length and circumstance than that of ''M.&nbsp;americanum'' and may have similarly exhibited degrees of sexual dimorphism.<ref>{{cite conference|last1=Smith|first1=Kathlyn M.|last2=Stoneburg|first2=Brittney E.|last3=Dooley|first3=Alton C.|year=2023|title=Tusk morphology and sexual dimorphism in the Pacific mastodon (''Mammut pacificus'')|conference=Society of Vertebrate Paleontology 83rd Annual Meeting|pages=402|url=https://vertpaleo.org/wp-content/uploads/2023/10/2023_SVP_Program-Final-10032023.pdf}}</ref>

=== Postcranial skeleton ===
[[File:Cohoes Mastodon, New York State Museum.jpg|thumb|left|"Cohoes Mastodon" skeleton, [[New York State Museum]]]]
As a result of proboscidean diagnoses focusing mostly on dentition, the postcranial anatomies of fossil proboscideans like ''Mammut'' are underrepresented in academic literature. Jennifer A. Hodgson ''et al''. compared the anatomies of ''Mammut'' and ''Mammuthus'', mentioning that their postcranial anatomies were studied previously by Stanley John Olsen in 1972 and recognizing that the two genera were only distantly related to each other.<ref name="osteology">{{cite book|editor-last1=Allmon|editor-first1=Warren D.|editor-last2=Nester|editor-first2=Peter L.|last1=Hodgson|first1=Jennifer A.|last2=Allmon|first2=Warren D.|last3=Nester|first3=Peter L.|last4=Sherpa|first4=James M.|last5=Chiment|first5=John J.|year=2008|title=Mastodon Paleobiology, Taphonomy, and Paleoenvironment in the Late Pleistocene of New York State: Studies on the Hyde Park, Chemung, and North Java Sites|chapter=Comparative osteology of late Pleistocene mammoth and mastodon remains from the Watkins Glen site, Chemung County, New York|publisher=Palaeontographica Americana|number=61|pages=301–367|url=https://www.researchgate.net/publication/269094378}}</ref><ref name="olsen">{{cite journal|last=Olsen|first=Stanley J.|year=1972|title=Osteology for the archaeologist: the American mastodon and the woolly mammoth|journal=Papers of the Peabody Museum of Archaeology and Ethnology, Harvard University, Cambridge|volume=56|number=3|pages=1–47|isbn=978-0-87365-197-4 |url=https://books.google.com/books?id=PoP_SFdFgQUC}}</ref> ''M. americanum'' is typically depicted as stocky based on postcranial evidence.<ref name="paleoart">{{cite journal|last1=Davis|first1=Matt|last2=Nye|first2=Benjamin D.|last3=Sinatra|first3=Gale M.|last4=Swartout|first4=William|last5=Sjӧberg|first5=Molly|last6=Porter|first6=Molly|last7=Nelson|first7=David|last8=Kennedy|first8=Alana A.U.|last9=Herrick|first9=Imogen|last10=Weeks|first10=Danaan DeNeve|last11=Lindsey|first11=Emily|display-authors=6|year=2022|title=Designing scientifically-grounded paleoart for augmented reality at La Brea Tar Pits|journal=Palaeontologia Electronica|number=25.1.a9|doi=10.26879/1191|doi-access=free}}</ref>

The [[vertebral column]] (also known as the backbone or spine) of ''Mammut'' is documented as having a highest point located in the shoulder's front like ''Mammuthus'', but the spines gradually decrease in length then increase slightly in the rear area. The number of ribs and vertebrae of ''Mammut'' is not well-documented in paleontological literature and may vary by individual. ''Mammut'' usually has 20&nbsp;[[thoracic vertebrae]] whereas ''Mammuthus'' usually has 19, but both have documented individuals with 18 of them. The reduction of thoracic vertebrae in ''Mammuthus'' is considered a derived trait also present in modern elephants. The "Watkins Glen mastodon," for example, has 7&nbsp;[[cervical vertebrae]], 20&nbsp;thoracic vertebrae, 3&nbsp;[[lumbar vertebrae]], and 5&nbsp;[[sacral vertebrae]]. They believed that ''Mammut'' could have had as many as 20&nbsp;[[rib]]s and that the back ribs were shorter and broader than that of ''Mammuthus''.<ref name="osteology"/> The tail of ''Mammut'' may have been made up of as many as up to 27&nbsp;[[caudal vertebrae]], suggesting that it had a long tail compared to gomphotheres and elephantids.<ref name="weight">{{cite journal |last=Larramendi |first=Asier |year=2015 |title=Shoulder height, body mass, and shape of proboscideans |journal=Acta Palaeontologica Polonica |volume=61 |issue=3 |pages=537–574 |doi=10.4202/app.00136.2014|doi-access=free}}</ref>

[[File:Age of the mastodon - side looking at cases - 27 FEB 0222 copy.jpg|thumb|''M.&nbsp;americanum'' skeleton, [[Nova Scotia Museum of Natural History]]]]
The [[scapula]] (or shoulder blade) of ''Mammut'' has a straight vertebral border, contrasting with a more concave vertebral border of ''Mammuthus''. Hodgson ''et al''. disagreed with the claim by Olsen in 1972 that the neck of the scapula is more constricted in ''Mammuthus primigenius'' than ''Mammut americanum'', since neither of the two ''M.&nbsp;americanum'' scapulae observed by the researchers have any high constriction there. The [[pelvis]] allows for identification of the sex of the species, as male ''Mammut'' individuals have a smaller [[pelvic outlet]] and wider [[ilium (bone)|ilium]] than female individuals.<ref name="osteology"/>

''Mammut'' has shorter and more robust limb bones compared to those of derived elephantids, probably the result of it retaining primitive anatomical traits. Both the [[humerus]] and [[radius (bone)|radius]] of the mammutid genus are robust for instance. The [[ulna]] has a slightly more developed [[olecranon process]] and a deeper [[trochlear notch]]. The [[femur]] is somewhat thick, short, and appears to have more expanded [[condyle]]s. Possibly, sexual dimorphism could be a factor behind the size of the femur itself. The [[tibia]] does not appear much different in both ''Mammut'' and ''Mammuthus'', whereas the [[fibula]] may have only had subtle and complex differences within the two genera. The bones within both the front feet and back feet have their own subtle and complex differences by genus, but both have smaller and more narrow hind feet than fore feet so that the latter bears more weight of the proboscideans.<ref name="osteology"/> In terms of postcranial anatomy, ''M.&nbsp;pacificum'' differs from ''M. americanum'' by the presence of six as opposed to five sacral vertebrae and the femur having a larger diameter of the middle shaft (or main cylindrical area).<ref name="pacificum"/>

=== External features ===
[[File:Mammut americanum Sergiodlarosa.jpg|thumb|left|Restoration of a mastodon with fur. The hypothesis that ''Mammut'' had thick coats of fur has been questioned.]]
The American mastodon (''M.&nbsp;americanum'') has typically been depicted as having shaggy and brown-colored fur in reconstructions, especially in over a century of [[paleoart]]. Despite this, there is little direct evidence supporting the idea that ''Mammut'' was actually covered in hair. Supposedly, only one find of fur belonging to the mastodon is of a skull with two small hairy patches of skin from the state of [[Wisconsin]] near the city of [[Milwaukee]]. These have only been described briefly in the original literature and have never been figured beyond one hair from a [[scanning electron microscope]] (SEM). K.F.&nbsp;Hallin and D.&nbsp;Gabriel in 1981 speculated that mastodons were indeed hairy but were more suited for semiaquatic lifestyles than tolerance of colder climates. Matt Davis ''et al''. in 2022 were tentative in accepting the source as evidence for hairiness, as they questioned whether ''Mammut'' needed thick coats for body warmth for their upper ranges at the [[Arctic]] and [[Subarctic]] and mentioned that it would not have needed them in subtropical climates like in [[Florida]].<ref name="paleoart"/><ref>{{cite conference|last1=Hallin|first1=K.F.|last2=Gabriel|first2=D.|year=1981|title=The first specimen of mastodon hair|conference=Geological Society of America 34th Annual Meeting of the Rocky Mountain Section, Abstracts with Program|volume=13|number=4|pages=199}}</ref><ref>{{cite journal|last=Hallin|first=K.F.|year=1983|title=Hair of the American mastodon indicates an adaptation to a semiaquatic habitat|journal=American Zoologist|volume=23|pages=949}}</ref>

Davis ''et al''. referenced that because [[Columbian mammoth]]s (''Mammuthus columbi'') were not thought to be hairy, it is unclear why mastodons would need thick coats in comparison. The former was typically depicted as hairless and the latter as hairy in paleoart, but the mastodon's preferences for closed or mixed habitats puts the speculations into question. They felt the need to portray the latter as hairy so that the average person could differentiate between the two species.<ref name="paleoart"/>

The concept of ''M.&nbsp;americanum'' having thick coats of fur was also subjected to study by Asier Larramendi in 2015. He acknowledged that hair is important for thermoregulation in extant elephants but that there is a negative correlation between body size and hair density in mammals. Some mammals have broken this trend before, however, as woolly mammoths (''Mammuthus primigenius'') evolved to have thick coats of hair and a very short tail in response to cold climates. The idea that the American mastodon had hair is possible because of the seasonal climates, but there are few preserved soft tissues to support this idea, referencing the hairs found in Wisconsin. The supposed evidence of hair reported in the 19th&nbsp;century were actually just [[green algae]] filaments. He concluded that the long tail and large body mass both contradict the hypothesis that ''M.&nbsp;americanum'' was covered with thick coats of fur, considering it to be probably exaggerated.<ref name="weight"/>

=== Size and weight ===
[[File:Male & female mastodons, front.jpg|thumb|''M. americanum'' male ("Beusching mastodon," left) and female ("Owosso mastodon," right), [[University of Michigan Museum of Natural History]]]]
According to Larramendi, the mammutids of the genus ''Mammut'' were amongst the largest proboscideans to have ever existed. This was especially the case with "''M.''"&nbsp;''borsoni'', which had a body mass of {{cvt|14–16|tonnes}} and probably exceptionally large body sizes. ''M.&nbsp;americanum'' in comparison to its relative was much smaller, but it was still large in its own right compared to extant elephants. The American mastodon did not grow taller than living elephants but it was much more robust in body build than them, in part due to its very broad pelvis. The Warren mastodon produces a body mass of nearby {{cvt|7.8|tonnes}} and had a shoulder height measuring {{cvt|289|cm}}. This robustness is so pronounced that ''M.&nbsp;americanum'' individuals could have been up to 80% heavier than an elephant with the same shoulder height. Larger than average individuals may have possibly had a shoulder height of {{cvt|325|cm}} and weighed up to {{cvt|11|tonnes}}. At mean calculations, ''M.&nbsp;americanum'' ranged at {{cvt|275|cm}} to {{cvt|305|cm}} at shoulder height and {{cvt|6.8|tonnes}} to {{cvt|9.2|tonnes}} in body mass. The average measurements of ''M.&nbsp;americanum'' are {{cvt|2.9|m}} in shoulder height and {{cvt|8|tonnes}} in body mass. These average estimates are larger than those of the Asian elephant. ''M.&nbsp;americanum'' had a smaller average shoulder height and a larger body mass compared to the [[African bush elephant]] (''Loxodonta africana'').<ref name="weight"/>
[[File:Warren mastodon size comparison.jpg|thumb|Skeletal diagram of the "Warren mastodon" specimen, an adult bull of ''M.&nbsp;americanum'' compared to a human]]
The size of the "Overmyer Mastodon," an individual skeleton recovered from the farm of Robert Overmyer northwest of [[Rochester, Indiana|Rochester]], [[Indiana]] in 1976, was estimated by Neal Woodman and Jon W. Branstrator in 2008. They estimated based on the length of the humerus ({{cvt|829|mm}}) that the shoulder height of the individual was {{cvt|230.2|cm}}, which they said was close to the average shoulder height of the species and comparable to a large female or small male. Similar to extant elephants, male American mastodon individuals tended to be larger than female individuals and tend to have larger and more strongly curved tusks, although the degree to which the body size is a factor in molar size is unclear.<ref name="overmyer">{{cite journal|last1=Woodman|first1=Neal|last2=Branstrator|first2=Jon W.|year=2008|title=The Overmyer Mastodon (Mammut Americanum) from Fulton County, Indiana|journal=The American Midland Naturalist|volume=159|issue=1|pages=125–146|doi=10.1674/0003-0031(2008)159[125:TOMMAF]2.0.CO;2}}</ref>

A relatively complete skeleton of ''Mammut'' sp. from the [[Gray Fossil Site]] in [[Tennessee]], which was first uncovered in 2015, dates to the latest Hemphillian, and has an elongated mandibular symphysis and large mandibular tusks, is thought to have been several tonnes larger than ''M.&nbsp;americanum'' and even several species of ''Mammuthus''. The specimens are still being prepared for further studies.<ref name="neogene"/><ref>{{cite conference|last=Hart|first=Brenna|year=2020|title=Manus biomechanics of a giant mastodon from the Gray Fossil Site suggests the ability to transverse uneven terrain in a karstic and mountainous refugium|conference=Society of Vertebrate Paleontology 80th Annual Meeting|pages=166|url=https://vertpaleo.org/wp-content/uploads/2021/03/SVP_2020_Program-Abstracts-Volume-FINAL-for-Publishing-1.27.2021.pdf}}</ref>

== Paleobiology ==
=== Diet ===
[[File:Mastodon color.jpg|thumb|left|Restoration of an American mastodon without fur by [[Heinrich Harder]]]]
The zygodont molar morphologies of mammutids suggest that they consistently occupied adaptations to [[folivore|folivorous]] diets throughout their evolutionary history. This means that mammutids such as ''Mammut'', because they retained zygodont molars, were built to browse on higher vegetation and did not shift towards grazing specializations or consistent mixed feeding. The stomach contents of ''M.&nbsp;americanum'' indicate that the species consumed [[spruce needle]]s, [[pine cone]]s, grass, and occasionally [[gourds]] plus [[vine leaves]]. Of note is that whereas mammutids of Eurasia went extinct by the early Pleistocene in association with more seasonal climates, ''Mammut'' survived in North America and became abundant, although the reason for the latter faunal trend does not have any offered explanation.<ref>{{cite book|editor-last1=Höhne|editor-first1=D.|editor-last2=Schwarz|editor-first2=W.|last=van der Made|first=Jean|year=2010|title=Elefantenreich: Eine Fossilwelt in Europa|chapter=The evolution of the elephants and their relatives in the context of a changing climate and geography|publisher=Landesamt für Denkmalpflege und Archälogie Sachsen-Anhalt & Landesmuseum für Vorgeschichte, Halle|pages=341–360|url=https://www.researchgate.net/publication/260869040}}</ref> The browsing specialization of ''Mammut'' is supported further by the [[coprolite]]s (or fossil dung) of ''M.&nbsp;americanum'', which are large-sized similar to extant elephants and predominantly consist of consumed woody contents but no grass.<ref>{{cite book|editor-last=Webb|editor-first=S. David|last1=Newsom|first1=Lee A.|last2=Mihlbachler|first2=Matthew C. |year=2006 |title=First Floridians and Last Mastodons: The Page-Ladson site in the Aucilla river |chapter=Chapter&nbsp;10: Mastodons (Mammut americanum) Diet Foraging Patterns Based on Analysis of Dung Deposits|publisher=Springer|pages=263–331|doi=10.1007/978-1-4020-4694-0_10}}</ref> Of the Pleistocene New World proboscideans, the American mastodon appears to have been the most consistent in browsing rather than grazing, consuming [[C3 carbon fixation|C<sub>3</sub>]] as opposed to [[C4 carbon fixation|C<sub>4</sub>]] plants, and occupying closed forests versus more open habitats. This dietary inflexibility may have prevented them from invading South America during the [[Great American Interchange]], due to the need to cross areas of grassland to do so.<ref>{{cite journal|last1=Pérez-Crespo|first1=Victor A.|last2=Prado|first2=José L.|last3=Alberdi|first3=Maria T.|last4=Arroyo-Cabrales|first4=Joaquín|last5=Johnson|first5=Eileen|year=2016|title=Diet and Habitat for Six American Pleistocene Proboscidean Species Using Carbon and Oxygen Stable Isotopes|journal=Ameghiniana |volume=53|issue=1|pages=39–51|doi=10.5710/AMGH.02.06.2015.2842|s2cid=87012003}}</ref>

The mastodon commonly browsed on woody plants (i.e. twigs) and fruits, occupying dense [[coniferous forest]]s made up of spruces (''[[Picea]]'') and pines (''[[Pinus]]'') within most of eastern North America. In Florida, it consumed twigs of the genus ''[[Taxodium]]'' as well as other woody plants and fruits. Based on [[isotopes of carbon|carbon isotopic analyses]] of mastodons in Florida, they had low δ13C values which indicate C<sub>3</sub> browsing specialization.<ref>{{cite journal|last1=Green|first1=Jeremy L.|last2=Semprebon|first2=Gina M.|last3=Solounias|first3=Nikos|year=2005|title=Reconstructing the palaeodiet of Florida ''Mammut americanum'' via low-magnification stereomicroscopy|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=223|issue=1–2|pages=34–48|doi=10.1016/j.palaeo.2005.03.026
|bibcode=2005PPP...223...34G }}</ref> The dietary preferences of North American ''Mammut'' are thought to have mirrored those of the older ''Zygolophodon'', which may have preferred living in closed forests and consuming conifers to avoid active competition with the bunodont gomphotheres and lophodont deinotheres in the Miocene of Europe.<ref>{{cite journal|last1=Březina|first1=Jakub|last2=Alba|first2=David M.|last3=Ivanov|first3=Martin|last4=Hanáček|first4=Martin|last5=Luján|first5=Àngel H.|year=2021|title=A middle Miocene vertebrate assemblage from the Czech part of the Vienna Basin: Implications for the paleoenvironments of the Central Paratethys|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=575|doi=10.1016/j.palaeo.2021.110473|bibcode=2021PPP...57510473B |url=https://ddd.uab.cat/record/241122 }}</ref> Most accounts of gut contents have identified coniferous twigs as the dominant element in their diet.<ref>{{cite journal|last1=Lepper|first1=Bradley T.|last2=Frolking|first2=Tod A.|last3=Fisher|first3=Daniel C.|last4=Goldstein|first4=Gerald|last5=Sanger|first5=Jon E.|last6=Wymer|first6=Dee Anne |last7=Ogden|first7=J. Gordon, III |last8=Hooge |first8=Paul E. |display-authors=6 |year=1991 |title=Intestinal contents of a late Pleistocene Mastodont from mid-continental North America |journal=Quaternary Research |volume=36 |issue=1|pages=120–125|bibcode=1991QuRes..36..120L|doi=10.1016/0033-5894(91)90020-6|hdl=2027.42/29243|s2cid=56160892 |url=https://deepblue.lib.umich.edu/bitstream/2027.42/29243/1/0000299.pdf|hdl-access=free}}</ref> In addition to twigs and leaves, as indicated by the "Heisler mastodon" of [[Michigan]] and the "[[Burning Tree mastodon]]" of Ohio, mastodons may have also consumed swamp grasses (''[[Glyceria]]'' and ''[[Zizania]]'') as well as semiaquatic and aquatic plants such as sedge marshes (''[[Carex]]'') that surrounded lakes. They may have additionally ingested other aquatic plants and aquatic invertebrates while consuming more than {{cvt|100|L}} of water from lakes a day.<ref>{{cite journal|last1=Birks|first1=Hilary H.|last2=van Geel|first2=Bas|last3=Fisher|first3=Daniel C.|last4=Grimm|first4=Eric C.|last5=Kuijper|first5=Wim J.|last6=van Arkel|first6=Jan|last7=van Reenen|first7=Guido B.A.|year=2019|title=Evidence for the diet and habitat of two late Pleistocene mastodons from the Midwest, USA|journal=Quaternary Research|volume=91|issue=2|pages=792–812|doi=10.1017/qua.2018.100|bibcode=2019QuRes..91..792B }}</ref> The temporal shifts in molar and limb bone sizes in mastodon populations from Missouri and Florida as well as apparent differences in body size between western and eastern populations suggest that ''M.&nbsp;americanum'' was an adaptable species for local environmental shifts. Regardless, it depended heavily on forested environments similar to tapirs, so significant closed vegetation losses of any sort could have impacted them.<ref>{{cite journal|last1=Green|first1=Jeremy L.|last2=DeSantis|first2=Larisa R.G.|last3=Smith|first3=Gregory James|year=2017|title=Regional variation in the browsing diet of Pleistocene Mammut americanum (Mammalia, Proboscidea) as recorded by dental microwear textures|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=487|pages=59–70|doi=10.1016/j.palaeo.2017.08.019|doi-access=free|bibcode=2017PPP...487...59G }}</ref>

As a result of the consistent browsing specializations of the genus, ''Mammut'' occupied an ecological niche that allowed it to actively [[niche partition]] (or occupy similar but niche ecological spaces) with other proboscideans of North America in the Neogene-[[Quaternary]]. In the Blancan, ''M.&nbsp;raki'' showed few morphological changes. In stark contrast, the contemporary gomphothere ''Stegomastodon'' showed progressive developments in response to increasingly arid and extensive grasslands from the Blancan up to the early Irvingtonian, with molar complexities resembling those of ''Mammuthus''.<ref name="stegomastodon"/> The morphology of ''Stegomastodon'' suggests thus that it was grazing-specialized.<ref name="stegomastodon2">{{cite journal|last1=Lucas|first1=Spencer G.|last2=Morgan|first2=Gary S.|last3=Spielmann|first3=Justin A.|last4=Pasenko|first4=Michael R.|last5=Aguilar|first5=Ricardo Hernán|year=2011 |title=Taxonomy and evolution of the Plio-Pleistocene proboscidean Stegomastodon in North America |journal=Current Research in the Pleistocene|volume=28|pages=173–175|url=https://www.researchgate.net/publication/362887774}}</ref> A more well-known example of niche partitioning occurred between mastodons and mammoths within the later Pleistocene (Irvingtonian-Rancholabrean). Mammoths had a broader range of diets that allow them to occupy mixed feeding to specialized grazing habits whereas mastodons were specialized browsers that nonetheless still could have consumed a variety of plants. Mammoth diets varied by region whereas those of mastodons remain unclear still. Both at times overlapped in C<sub>3</sub> resource usages, although whether this represents browsing or grazing in the case of mammoths remains unclear.<ref>{{cite journal|last1=Pardi|first1=Melissa I.|last2=DeSantis|first2=Larisa R.G.|year=2022|title=Interpreting spatially explicit variation in dietary proxies through species distribution modeling reveals foraging preferences of mammoth (''Mammuthus'') and American mastodon (''Mammut americanum'')|journal=Frontiers in Ecology and Evolution|volume=10|doi=10.3389/fevo.2022.1064299|doi-access=free}}</ref>

=== Social behaviors ===
[[File:Mastdon Wheaton College.jpg|thumb|American mastodon ("Perry mastodon") skeleton with silhouette in back including the trunk, [[Wheaton College (Illinois)]]]]
American mastodons may have lived in herds, and it is possible that they were smaller than mammoth herds on average.<ref>{{cite journal|last1=Bonhof|first1=Wouter J.|last2=Pryor|first2=Alexander J.E.|year=2022|title=Proboscideans on Parade: A review of the migratory behaviour of elephants, mammoths, and mastodons|journal=Quaternary Science Reviews|volume=277|number=107304|doi=10.1016/j.quascirev.2021.107304|bibcode=2022QSRv..27707304B |hdl=10871/128047|hdl-access=free}}</ref> Based on the characteristics of mastodon bone sites and strontium and oxygen isotopes from tusks, it can be inferred that, as in modern proboscideans, the mastodon social group consisted of adult females and young, living in bonded groups called mixed herds. The males abandoned the mixed herds once reaching sexual maturity and lived either alone or in male bond groupings.<ref name="buesching">{{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.|year=2022|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|pmid=35696566|pmc=9231495 |bibcode=2022PNAS..11918329M |issn=0027-8424}}</ref><ref name="Haynes">{{cite journal|last1=Haynes|first1=G.|last2=Klimowicz|first2=J.|year=2003|title=Mammoth (''Mammuthus'' spp.) and American mastodont (''Mammut americanum'') bonesites: what do the differences mean?|journal=Advances in Mammoth Research|volume=9|pages=185–204|url=http://natuurtijdschriften.nl/record/538680}}</ref> As in modern elephants,<ref>{{cite book|author= Sukumar, R.|title= The Living Elephants: Evolutionary Ecology, Behaviour, and Conservation|url=https://archive.org/details/livingelephantse00suku_0|url-access=registration|pages=[https://archive.org/details/livingelephantse00suku_0/page/262 262]|date= September 11, 2003|publisher= Oxford University Press, USA|isbn= 978-0-19-510778-4 |oclc= 935260783}}</ref> there probably was no seasonal synchrony of mating activity, with both males and females seeking out each other for mating when sexually active.<ref name="Haynes"/> Mastodons and other Pleistocene proboscideans may have used landscapes seasonally then migrated to suitable areas to mate or give birth. It is estimated that it may have taken 9 to 12 years for American mastodon females to become mature enough for reproduction, and they may have slowly reproduced single calves at a time.<ref name="buesching"/>

The social behaviors of male mastodon were inferred from one individual skeleton known as the "Buesching mastodon" (known informally as "Fred"),<ref>{{cite news|last=McNamee|first=Kai|date=7 July 2022|title=The story of Fred the mastodon, who died looking for love|work=National Public Radio|url=https://www.npr.org/2022/07/07/1109839726/research-news-science-nature-mastodon|access-date=2 February 2024}}</ref> which was recovered from a peat farm near [[Fort Wayne]], Indiana in 1998. The mastodon individual lived during the later part of the [[Bølling–Allerød warming]] period when human populations were present. The Buesching mastodon's tusks grew for about 30 years, and he lived for 34 years total, an approximate lifespan comparable to other males. He may have had engaged in aggressive behavior from [[musth]], although it may have been season-specific compared to living elephants given climatic conditions in North America. He likely engaged in [[intraspecific competition]] late in his life with other males during the spring or early summer, and he had tusk fractures and may have been severely wounded from a {{cvt|4|cm}} to {{cvt|5|cm}} puncture to the right-sided temporal fossa. Multiple other males are recorded to have had severe wounds resulting from male-male musth fighting.<ref name="buesching"/> The Buesching mastodon likely considered central Indiana his main home but went on seasonal migrations in his lifetime. He could have traveled hundreds of kilometers in the process and engaged with mates outside of the herd he was born from. Around his last moments, he probably wandered around in vagabondlike behaviors and spent little time in the area where his skeleton was found. His inferred behavior is quite similar to extant elephants.<ref>{{cite journal|last=Price|first=Gilbert J.|year=2022|title=Wandering mastodons reveal the complexity of Ice Age extinctions|journal=Proceedings of the National Academy of Sciences|volume=119|issue=25|pages=e2118329119 |doi=10.1073/pnas.2118329119|doi-access=free |pmid=35696566 |pmc=9231495 |bibcode=2022PNAS..11918329M }}</ref>

== Paleoecology ==
=== Distribution ===
[[File:Mammut pacificus Mammut americanum fossil distribution.jpg|thumb|North American map of the distributions of ''M. americanum'' (blue) and ''M. pacificum'' (red) fossil localities of the [[Irvingtonian]]-[[Rancholabrean]]]]
The range of most species of ''Mammut'' is unknown as their occurrences are restricted to few localities, the exception being the American mastodon (''M.&nbsp;americanum''), which is one of the most widely distributed Pleistocene proboscideans in North America. ''M. americanum'' fossil sites range in time from the [[Blancan]] to [[Rancholabrean]] faunal stages and in locations from as far north as Alaska, as far east as Florida, and as far south as the state of Puebla in central Mexico.<ref>{{cite journal|last1=Lucas|first1=Spencer G.|last2=Guillermo|first2=Alvarado Induni|year=2010|title=Fossil Proboscidea from the upper Cenozoic of Central America: taxonomy, evolutionary and paleobiogeographic significance|journal=Revista Geológica de América Central|volume=42|issue=42 |pages=9–42|doi=10.15517/rgac.v0i42.4169}}</ref><ref>{{cite book|last1=Polaco|first1=O. J.|last2=Arroyo-Cabrales|first2=J.|last3=Corona-M.|first3=E.|last4=López-Oliva|first4=J. G.|editor1-last=Cavarretta|editor1-first=G. |editor2-last=Gioia |editor2-first=P. |editor3-last=Mussi |editor3-first=M.|editor4-last=Palombo|editor4-first=M. R.|date=2001|title=The World of Elephants – Proceedings of the 1st International Congress, Rome October 16–20, 2001|chapter=The American Mastodon ''Mammut americanum'' in Mexico|publisher=Consiglio Nazionale delle Ricerche|pages=237–242|jstor=30055281 |isbn=88-8080-025-6|url=https://www.jstor.org/stable/30055281}}</ref><ref name="neogene"/> ''M. americanum'' was most common in the eastern United States but rarer in the western US in comparison. ''M. pacificum'' is known across California and present as far north as southern [[Idaho]], but it was apparently absent from both the [[Sonoran Desert]] and [[Mojave Desert]] regions. The elevated-controlled distributions of coniferous forests within the [[Rocky Mountain]] region may have limited populations of ''Mammut'' compared to the other Plio-Pleistocene proboscideans.<ref name="pacificum"/> The easternmost range of the species was in what is now [[Montana]] in the Irvingtonian but may have been extirpated from the area as a result of [[Illinoian (stage)|Illinoian glaciation]].<ref>{{cite journal|last1=McDonald|first1=Andrew T.|last2=Atwater|first2=Amy L.|last3=Dooley Jr.|first3=Alton C.|last4=Hohman|first4=Charlotte J.H.|year=2020|title=The easternmost occurrence of Mammut pacificus (Proboscidea: Mammutidae), based on a partial skull from eastern Montana, USA|journal=PeerJ|volume=8|pages=e10030 |doi=10.7717/peerj.10030|doi-access=free|pmid=33240588 |pmc=7676352}}</ref> An isolated record of ''M. americanum'' is known from [[Honduras]], where the genus is not recorded to have extended beyond.<ref>{{cite journal|last1=Arroyo-Cabrales|first1=Joaquín|last2=Polaco|first2=Oscar J.|last3=Laurito|first3=César|last4=Johnson|first4=Eileen|last5=Alberdi|first5=María Teresa|last6=Zamora|first6=Ana Lucía Valerio|year=2007|title=The proboscideans (Mammalia) from Mesoamerica|journal=Quaternary International|volume=169–170|pages=17–23|doi=10.1016/j.quaint.2006.12.017|bibcode=2007QuInt.169...17A }}</ref>

''M. matthewi'' is known by a wide distribution range, its westernmost range being in California from the [[Horned Toad Formation]] in the late Hemphillian.<ref name="neogene"/> It has also apparently been identified from the latest Hemphillian based on skull material from the [[Pascagoula Formation]] in [[Tunica Hills]], [[Louisiana]]. This suggests that ''Mammut'' already had an eastern range in the United States by the latest Miocene or earliest Pliocene.<ref>{{cite conference |last=White |first=Connor D. |year=2023 |title=Partial cranium and associated tusks of Mio-Pliocene ''Mammut'' (Mammalia, Proboscidea) from Pascagoula Formation in Tunica Hills, Louisiana |url=https://vertpaleo.org/wp-content/uploads/2023/10/2023_SVP_Program-Final-10032023.pdf |conference=Society of Vertebrate Paleontology 83rd Annual Meeting |pages=443–444}}</ref> Similarly, the same species is recorded from the Palmetto Fauna locality ([[Bone Valley Formation]]) in [[Brewster, Florida|Brewster]], Florida in the latest Hemphillian while ''Mammut'' sp. is recorded from the Gray Fossil Site in Tennessee.<ref name="neogene"/>

The American mastodon was only present in the far north of North America during [[interglacial]] periods, with mitochondrial genome analysis suggesting that separate populations repeatedly colonised the region before becoming [[extirpated]] during glacial periods.<ref name="genomes">{{cite journal|last1=Karpinski|first1=Emil|last2=Hackenberger|first2=Dirk|last3=Zazula|first3=Grant|last4=Widga|first4=Chris|last5=Duggan|first5=Ana T.|last6=Golding|first6=G. Brian|last7=Kuch|first7=Melanie|last8=Klunk|first8=Jennifer|last9=Jass|first9=Christopher N.|last10=Groves|first10=Pam|last11=Druckenmiller|first11=Patrick|last12=Schubert|first12=Blaine W.|last13=Arroyo-Cabrales|first13=Joaquin|last14=Simpson|first14=William F.|last15=Hoganson|first15=John W.|last16=Fisher|first16=Daniel C.|last17=Ho|first17=Simon Y.W.|last18=MacPhee|first18=Ross D.E.|last19=Poinar|first19=Hendrick N.|year=2020|title=American mastodon mitochondrial genomes suggest multiple dispersal events in response to Pleistocene climate oscillations|journal=Nature Communications|volume=11|issue=1|page=4048|bibcode=2020NatCo..11.4048K|doi=10.1038/s41467-020-17893-z|pmc=7463256|pmid=32873779|doi-access=free}}</ref> A 2022 study of ancient  [[environmental DNA]] from the [[Kap Kobenhavn Formation]] of northern [[Greenland]], dating the [[Early Pleistocene]], 2 million years ago, identified preserved DNA fragments of mastodons. This suggests that the mammutids ranged as far north as Greenland during optimal conditions. Around this time, northern Greenland was 11–19 °C warmer than the [[Holocene]], with a [[Taiga|boreal forest]] hosting a species assemblage with no modern analogue. These are among the oldest DNA fragments ever sequenced.<ref>{{cite journal|last1=Kjær|first1=Kurt H.|last2=Winther Pedersen|first2=Mikkel|last3=De Sanctis|first3=Bianca|last4=De Cahsan|first4=Binia|last5=Korneliussen|first5=Thorfinn S.|last6=Michelsen|first6=Christian S.|last7=Sand|first7=Karina K.|last8=Jelavić|first8=Stanislav|last9=Ruter|first9=Anthony H.|last10=Schmidt|first10=Astrid M. A.|last11=Kjeldsen|first11=Kristian K.|last12=Tesakov|first12=Alexey S.|last13=Snowball|first13=Ian|last14=Gosse|first14=John C.|last15=Alsos|first15=Inger G.|date=December 2022|title=A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA|journal=Nature|language=en|volume=612|issue=7939|pages=283–291|doi=10.1038/s41586-022-05453-y|pmid=36477129|pmc=9729109|bibcode=2022Natur.612..283K|issn=1476-4687}}</ref><ref>{{cite web|last=Pappas|first=Stephanie|title=World's Oldest DNA Discovered, Revealing Ancient Arctic Forest Full of Mastodons|url=https://www.scientificamerican.com/article/worlds-oldest-dna-discovered-revealing-ancient-arctic-forest-full-of-mastodons/|access-date=2022-12-08|website=Scientific American|language=en}}</ref>

=== Late Neogene-Quaternary North America ===
[[File:Natural History Museum of LA Teleoceras.jpg|thumb|''[[Teleoceras]] fossiger'' skeleton, [[Natural History Museum of Los Angeles County]]. ''Mammut'' coexisted with [[rhinocerotid]]s up to the Pliocene.]]
The overall paleontological record of the Neogene of North America is relatively incomplete compared to other areas of the world. This is the result of a greater fossil record bias of western North America compared to eastern North America, meaning that the western half is better understood in terms of evolutionary and climatic trends while the eastern half is poorly understood. During the late Neogene (8-5 Ma), C<sub>4</sub> grasslands spread throughout the North American continent and replaced woodland habitats. In eastern North America were relict woodlands in an increasingly drier climate followed by a large faunal turnover.<ref>{{cite thesis|type=MS|last=Baumgartner|first=Kyrie A.|year=2014|title=Neogene Climate Change in Eastern North America: A Quantitative Reconstruction|publisher=East Tennessee State University|url=https://core.ac.uk/download/pdf/214070254.pdf}}</ref> There was a long-term decline of genus-level faunal diversity, with many large-sized herbivores going extinct. Many of the surviving herbivorous faunas were thus adapted for drier and more open habitats resulting from cooling and increase in seasonality.<ref>{{cite journal|last=Fox|first=David L.|year=2000|title=Growth increments in Gomphotherium tusks and implications for late Miocene climate change in North America|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=156|issue=3–4|pages=327–348|doi=10.1016/S0031-0182(99)00148-0|bibcode=2000PPP...156..327F }}</ref>

[[File:Megalonyx jeffersonii - Natural History Museum of Utah - DSC07263.JPG|thumb|left|''[[Megalonyx]] jeffersonii'' skeleton, [[Natural History Museum of Utah]]. ''Megalonyx'' mostly likely descended from ''[[Pliometanastes]]'' and was present in North America since the late Hemphillian.<ref>{{cite journal|last1=McDonald|first1=H. Gregory|last2=Carranza-Castañeda|first2=Oscar|year=2017|title=Increased xenarthran diversity of the Great American Biotic Interchange: a new genus and species of ground sloth (Mammalia, Xenarthra, Megalonychidae) from the Hemphillian (late Miocene) of Jalisco, Mexico|journal=Journal of Paleontology|volume=91|issue=5|pages=1069–1082|doi=10.1017/jpa.2017.45|bibcode=2017JPal...91.1069M }}</ref>]]
The earliest undisputed record of ''Mammut'' ''sensu stricto'' was of ''M. nevadanum'' in the Thousand Creek Formation in Nevada.<ref name="neogene"/> Coexistent with the mammutid species were a large variety of other mammals, namely those of the [[Artiodactyla]] ([[antilocaprid]]s, [[camelid]]s, [[tayassuid]]s), [[Carnivora]] ([[canid]]s, [[felid]]s, [[mustelid]]s, [[Ursidae|ursid]]s), [[Eulipotyphla]] ([[talpid]]s), [[Lagomorpha]] ([[leporid]]s), [[Perissodactyla]] ([[equid]]s, [[rhinocerotid]]s), and [[Rodentia]] ([[aplodontiid]]s, [[castorid]]s, [[geomyid]]s, [[heteromyid]]s, [[cricetid]]s, [[mylagaulid]]s, and [[sciurid]]s).<ref>{{cite book|last1=Prothero|first1=Donald R.|last2=Davis|first2=Edward Byrd|year=2008|title=Neogene Mammals: Bulletin 44|chapter=Magnetic stratigraphy of the Upper Miocene (Early Hemphillian) Thousand Creek Formation, Northwestern Nevada|volume=44|pages=233–238|chapter-url=https://books.google.com/books?id=vW_aBwAAQBAJ&pg=PA233}}</ref> The latest Hemphillian of Florida based on the Palmetto Fauna of the Bone Valley Formation records the coexistence of ''M. matthewi'' with similar types of faunas, namely [[Pilosa]] ([[megalonychid]]s), Eulipotyphla (talpids), Lagomorpha (leporids), Carnivora ([[borophagine]] canids, [[Caninae|canine]] canids, ursids, [[procyonid]]s, mustelids including [[lutrine]]s, [[Felinae|feline]] felids, [[machairodontine]] felids), Proboscidea (gomphotheres), Perissodactyla (tapirs, rhinocerotids, [[hipparionine]] equids), and Artiodactyla (tayassuids, [[protoceratid]]s, camelids, "[[pseudoceratine]]s," [[cervid]]s, antilocaprids).<ref>{{cite book|editor-last1=Wang|editor-first1=Xiaoming|editor-last2=Barnes|editor-first2=Lawrence G.|last1=Webb|first1=S. David|last2=Hulbert Jr.|first2=Richard C.|last3=Morgan|first3=Gary S.|last4=Evans|first4=Helen F.|year=2008|title=Geology and Vertebrate Paleontology of Western and Southern North America|chapter=Terrestrial mammals of the Palmetto Fauna (early Pliocene, latest Hemphillian) from the Central Florida Phosphate District|publisher=Natural History Museum Los Angeles County Science|volume=41|pages=293–312|url=https://www.researchgate.net/publication/257618973}}</ref> North America in the late Neogene is understood to have undergone a long-term decline in large mammal diversity (i.e. the [[Dromomerycidae]], "[[Blastomerycinae]]," Rhinocerotidae) as a result of C<sub>4</sub> grassland expansion, cooler climates, and increased seasonality.<ref>{{cite journal|last1=Figueirido|first1=Borja|last2=Janis|first2=Christine M.|last3=Pérez-Claros|first3=Juan A.|last4=De Renzi|first4=Miquel|last5=Palmqvist|first5=Paul|year=2012|title=Cenozoic climate change influences mammalian evolutionary dynamics|journal=Proceedings of the National Academy of Sciences|volume=109|issue=3|pages=722–727|doi=10.1073/pnas.1110246108|doi-access=free |pmid=22203974 |pmc=3271923|bibcode=2012PNAS..109..722F }}</ref><ref>{{cite journal|last1=Wang|first1=Bian|last2=Secord|first2=Ross|year=2020|title=Paleoecology of Aphelops and Teleoceras (Rhinocerotidae) through an interval of changing climate and vegetation in the Neogene of the Great Plains, central United States|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=542|doi=10.1016/j.palaeo.2019.109411|doi-access=free|bibcode=2020PPP...54209411W }}</ref>

The Blancan fossil record suggests a maximum known diversity of four species of ''Mammut'' (''M. americanum'', ''M. vexillarius'', ''M. raki'', and ''M. cosoensis'').<ref name="neogene"/> However, the Blancan record of ''Mammut'' is relatively rare.<ref>{{cite journal|last1=Lucas|first1=Spencer G.|last2=Morgan|first2=Gary S.|year=1999|title=The oldest Mammut (Mammalia: proboscidea) from New Mexico|journal=New Mexico Geology|volume=21|number=1|pages=10–12|doi=10.58799/NMG-v21n1.10}}</ref> ''M. raki'' from the [[Palomas Formation]] of Truth or Consequences in New Mexico is recorded with a few other mammalian faunas, namely the megalonychid [[ground sloth]] ''Megalonyx'', the pocket gopher ''[[Geomys]]'', the cricetid ''[[Sigmodon]]'', the equin ''[[Equus (genus)|Equus]]'', the hipparionine ''[[Nannippus]]'', and the camelid ''[[Camelops]]''.<ref>{{cite journal|last1=Morgan|first1=Gary S.|last2=Harris|first2=Arthur H.|year=2015|title=Pliocene and Pleistocene vertebrates of New Mexico|journal=New Mexico Museum of Natural History and Science Bulletin|volume=68|pages=233–427|url=https://books.google.com/books?id=S--oDQAAQBAJ&pg=PA233}}</ref> A late Blancan locality known as the Fish Springs Flat Fauna in Nevada reveals that fossils of ''M. americanum'' were found with those of the leporid ''[[Hypolagus]]'', lutrine ''[[Satherium]]'', equid ''Equus'', camelid ''[[Gigantocamelus]]'', gopher ''[[Thomomys]]'', and the ground squirrel ''[[Spermophilus]]''.<ref name="stratigraphy">{{cite book|editor-last=Woodburne|editor-first=Michael|last1=Bell|first1=Christopher J.|last2=Lundelius Jr.|first2=Ernest L.|last3=Barnosky|first3=Anthony D.|last4=Graham|first4=Russell W.|last5=Lindsay|first5=Everett H.|last6=Ruez|first6=Dennis R.|last7=Semken|first7=Holmes A.|last8=Webb|first8=S. David|last9=Zakrzewski|first9=Richard J.|year=2004|title=Late Cretaceous and Cenozoic Mammals of North America|chapter=Chapter 7: The Blancan, Irvingtonian, and Rancholabrean Mammal Ages|publisher=Columbia University Press|pages=232–314|doi=10.7312/wood13040-009}}</ref>

In the Irvingtonian, only ''M. americanum'' is recorded to have crossed past the Blancan while ''M. pacificum'' replaced the other Blancan species.<ref name="pacificum"/> By this time, ''Mammut'' would have coexisted with the elephantid ''Mammuthus'' and the gomphotheres ''Cuvieronius'' and ''Stegomastodon'', although the latter failed to survive past the early Irvingtonian.<ref>{{cite journal|last1=Lucas|first1=Spencer G.|last2=Morgan|first2=Gary S.|last3=Estep|first3=John W.|last4=Mack|first4=Greg H.|last5=Hawley|first5=John W.|year=1999|title=Co-Occurrence of the Proboscideans Cuvieronius, Stegomastodon, and Mammuthus in the Lower Pleistocene of Southern New Mexico|journal=Journal of Vertebrate Paleontology|volume=19|number=3|pages=595–597|doi=10.1080/02724634.1999.10011169|jstor=4524020 |bibcode=1999JVPal..19..595L |url=https://www.jstor.org/stable/4524020}}</ref><ref name="stegomastodon2"/> The Middle Pleistocene sites are scarce in North America compared to the Late Pleistocene sites,<ref>{{cite journal|last=Schultz|first=Gerald E.|year=2010|title=Pleistocene (Irvingtonian, Cudahyan) vertebrates from the Texas Panhandle, and their geographic and paleoecologic significance|journal=Quaternary International|volume=217|issue=1–2|pages=195–224|doi=10.1016/j.quaint.2009.12.012|bibcode=2010QuInt.217..195S }}</ref> but from the Irvingtonian to the Rancholabrean, repeated glacial events occurred that led to repeated formations of major ice sheets in northern North America.<ref>{{cite journal|last1=Hughes|first1=Philip D.|last2=Gibbard|first2=Philip L.|last3=Ehlers|first3=Jürgen|year=2020|title=The "missing glaciations" of the Middle Pleistocene|journal=Quaternary Research|volume=96|pages=161–183|doi=10.1017/qua.2019.76|bibcode=2020QuRes..96..161H |url=https://pure.manchester.ac.uk/ws/files/144687057/Hughesetal_MissingGlaciations_FINAL_withFigs.pdf }}</ref> The [[Port Kennedy Bone Cave]] of Pennsylvania is of Irvingtonian age (Middle Pleistocene) and reveals that during this time, ''M. americanum'' was present with the megalonychid ''Megalonyx wheatleyi'', the [[Tremarctinae|tremarctine]] bear ''[[Arctodus|Arctodus pristinus]]'', the [[jaguar]] (''Panthera onca''), the felid ''[[Miracinonyx|Miracinonyx inexpectatus]]'', and the machairodontine ''[[Smilodon|Smilodon gracilis]]''.<ref name="stratigraphy"/> The Big Bone Lick locality in Kentucky, which dates to the latest Pleistocene (Rancholabrean), indicates the coexistence of the American mastodon with the extant [[reindeer]] (''Rangifer tarandus'') along with various other extinct [[megafauna]] like ancient [[bison]] (''[[Bison antiquus]]''), the [[Caprinae|caprine]] [[bovid]] ''[[Bootherium|Bootherium bombifrons]]'', [[mylodontid]] ground sloth ''[[Paramylodon|Paramylodon harlani]]'', megalonychid ''Megalonyx jeffersoni'', true deer ''[[Cervalces|Cervalces scotti]]'', equid ''[[Equus complicatus]]'', and the Columbian mammoth.<ref>{{cite journal|last1=Storrs|first1=Glenn W.|last2=McDonald|first2=H. Gregory|last3=Scott|first3=Eric|last4=Genheimer|first4=Robert A.|last5=Hedeen|first5=Stanley E.|last6=Schwalbach|first6=Cameron E.|year=2023|title=Field Guide to Big Bone Lick, Kentucky: Birthplace of American Vertebrate Paleontology|journal=Kentucky Geological Survey|series=13|issue=2 |pages=1–54|doi=10.13023/kgs13sp22023|url=https://uknowledge.uky.edu/kgs_sp/1/}}</ref>

== Relationship with humans ==
[[File:Clovis spearpoints - Cleveland Museum of Natural History.jpg|thumb|left|[[Clovis culture|Clovis]] spearpoints, [[Cleveland Museum of Natural History]]]]
The exact timing of [[human]] (''Homo sapiens'') arrival to temperate North America is unclear, but they likely arrived to North America ∼19,000–14,000 [[radiocarbon calibration|calibrated]] years [[Before Present]]. They are known within the archeological record as [[Paleoindian]]s and eventually gave rise to modern-day Native Americans.<ref>{{cite journal|last1=White|first1=John T.|last2=Henry|first2=Auréade|last3=Kuehn|first3=Stephen|last4=Loso|first4=Michael G.|last5=Rasic|first5=Jeffrey T.|year=2022|title=Terminal Pleistocene human occupation of the upper Copper River basin, southern Alaska: Results of test excavations at Nataeł Na'|journal=Quaternary International|volume=640|pages=23–43|doi=10.1016/j.quaint.2022.08.012|bibcode=2022QuInt.640...23W |url=https://hal.science/hal-03780826/file/1-s2.0-S1040618222002749-main.pdf }}</ref> Of interest is that in the [[Clovis culture]] phase, there is evidence that Clovis hunters targeted contemporary proboscideans based on archeological "kill sites." Clovis projectile points and other artifacts have been found in association with both mammoths and mastodons. The former has more frequent evidence of having been hunted by Clovis hunters while mastodons have much fewer in comparison. Todd A. Surovell and Nicole M. Waguespack in 2008 hypothesized that Clovis hunters in North America hunted proboscideans more often than those in any other continent. They addressed that preservation biases of larger mammals in archeological sites may have caused higher representations of proboscidean kill sites but suggested that regardless, Clovis hunters were likely specialized in hunting large game.<ref>{{cite journal|last1=Surovell|first1=Todd A.|last2=Waguespack|first2=Nicole M.|year=2008|title=How many elephant kills are 14?: Clovis mammoth and mastodon kills in context|journal=Quaternary International|volume=191|issue=1|pages=82–97|doi=10.1016/j.quaint.2007.12.001|bibcode=2008QuInt.191...82S }}</ref>

As of present, 2 definite ''Mammut'' kill sites compatible with Clovis [[lithic technology]] have been recorded compared to 15 of ''Mammuthus'' and 1 of ''Cuvieronius''. These two kill sites are thought to be from [[Kimmswick]], Missouri and Pleasant Lake in [[Washtenaw County]], Michigan.<ref>{{cite journal|last1=Grayson|first1=Donald K.|last2=Meltzer|first2=David J.|year=2015|title=Revisiting Paleoindian exploitation of extinct North American mammals|journal=Journal of Archaeological Science|volume=56|pages=177–193|doi=10.1016/j.jas.2015.02.009|bibcode=2015JArSc..56..177G }}</ref><ref name="site">{{cite journal|last=Haynes|first=Gary|year=2022|title=Sites in the Americas with Possible or Probable Evidence for the Butchering of Proboscideans|journal=PaleoAmerica|volume=8|issue=3|pages=187–214|doi=10.1080/20555563.2022.2057834}}</ref><ref name="storage">{{cite book|editor-last1=Konidaris|editor-first1=George Dimitri|editor-last2=Barkai|editor-first2=Ran|editor-last3=Tourloukis|editor-first3=Vangelis|editor-last4=Harvati|editor-first4=Katerina|last=Fisher|first=Daniel C.|year=2021|title=Human-Elephant Interactions: From Past to Present|chapter=Chapter 16: Underwater carcass storage and processing of marrow, brains, and dental pulp: Evidence for the role of proboscideans in human subsistence|publisher=Tübingen University Press|pages=407–435|doi=10.15496/publikation-55583}}</ref> Whether various other sites can be confirmed as proboscidean butchery sites appear subjective, largely depending on the views of different authors.<ref>{{cite journal|last1=Mackie|first1=Madeline E.|last2=Haas|first2=Randall|year=2021|title=Estimating the frequency of coincidental spatial associations between Clovis artifacts and proboscidean remains in North America|journal=Quaternary Research|volume=103|pages= 182–192|doi=10.1017/qua.2021.1|bibcode=2021QuRes.103..182M }}</ref> It is uncertain if Clovis people had hunting strategies of proboscideans similar to tribal Africans, but the Clovis points likely indicate usage as spears for thrusting or throwing at proboscideans (there are disagreements to whether they indicate multiple other usages, however).<ref>{{cite journal|last1=Kilby|first1=J. David|last2=Surovell|first2=Todd A.|last3=Huckell|first3=Bruce B.|last4=Ringstaff|first4=Christopher W.|last5=Hamilton|first5=Marcus J.|last6=Haynes Jr.|first6=C. Vance|year=2022|title=Evidence supports the efficacy of Clovis points for hunting proboscideans|journal=Journal of Archaeological Science: Reports|volume=45|doi=10.1016/j.jasrep.2022.103600|bibcode=2022JArSR..45j3600K }}</ref><ref>{{cite journal|last1=Eren|first1=Metin I.|last2=Meltzer|first2=David J.|last3=Story|first3=Brett|last4=Buchanan|first4=Briggs|last5=Yeager|first5=Don|last6=Bebber|first6=Michelle R.|year=2022|title=Not just for proboscidean hunting: On the efficacy and functions of Clovis fluted points|journal=Journal of Archaeological Science: Reports|volume=45|doi=10.1016/j.jasrep.2022.103601|doi-access=free|bibcode=2022JArSR..45j3601E }}</ref>

According to the American paleontologist [[Daniel Fisher (paleontologist)|Daniel C. Fisher]], the "Heisler mastodon" site in [[Calhoun County, Michigan|Calhoun County]], Michigan, which recovered about 50% of the skeleton, was proof of meat caching in a pond by Paleoindians in the late Pleistocene. This hypothesis opposes the notion that proboscideans ended up unable to disentangle themselves in marsh wetlands, which he said there is no evidence of. His hypothesis was based on his experiment with partial carcasses of a horse that was preserved in a shallow lake then extracted as well as a [[Moravian Church|Moravian]] missionary's testimony of [[Inuit]] retrieving caribou carcasses from lakes that they probably placed as storage in the cases of excess meat or future limited hunting successes. Fisher said that if his theory is true, then Paleoindian interactions with megafauna (hunting and scavenging) are far more complex than initially thought.<ref name="storage"/><ref name="site"/>

[[File:Manis-Mastodon-rib-embedded-object-Sequim-Museum-and-Arts-Center.jpg|thumb|Cast of a right rib of the "Manis mastodon" with an embedded object and healed wound, [[Sequim Museum & Arts]]. The wound has been hypothesized to be the result of pre-Clovis hunting from several sources.]]
In 2023, [[Michael R. Waters]] et al. suggested that the [[Manis Mastodon site]] in [[Washington (state)|Washington]] state supported evidence of a mastodon hunt ~13,900 cal. years BP, some 900 years before Clovis culture. Their study was a continuation of a 2011 anatomical study that proposed that osseous (bone) pieces found in a right rib of a mastodon represented fragmented tips of a projectile point, but it had been repeatedly challenged by other authors. Based on anatomical reevaluations, they determined that the bone fragments were embedded in the Manis mastodon rib while it was alive, as evident by the visible healing around the wounded area. Waters and his colleagues stated that the bone pieces were from an external source, explainable by human-made projectile points. They rejected alternate explanations for why bone fragments ended up in the Manis mastodon rib. Based on this, they envisioned that the mastodon individual was wounded by pre-Clovis hunters and got away, giving it time to heal. Afterwards, it died either by natural causes and was scavenged by humans, or it was killed by them on another attack then butchered. This site proves the existence of pre-Clovis hunting technology that the earliest people brought with them when dispersing to North America and made localized adaptations of.<ref>{{cite journal|last1=Waters|first1=Michael R.|last2=Newell|first2=Zachary A.|last3=Fisher|first3=Daniel C.|last4=McDonald|first4=H. Gregory|last5=Han|first5=Jiwan|last6=Moreno|first6=Michael|last7=Robbins|first7=Andrew|year=2023|title=Late Pleistocene osseous projectile point from the Manis site, Washington—Mastodon hunting in the Pacific Northwest 13,900 years ago|journal=Science Advances|volume=9|issue=5|pages=eade9068 |doi=10.1126/sciadv.ade9068|pmid=36724281 |pmc=9891687|bibcode=2023SciA....9E9068W }}</ref><ref>{{cite journal|last1=Waters|first1=Michael R.|last2=Stafford Jr.|first2=Thomas W.|last3=McDonald|first3=H. Gregory|last4=Gustafson|first4=Carl|last5=Rasmussen|first5=Morten|last6=Cappelini|first6=Enrico|last7=Olsen|first7=Jesper V.|last8=Szklarczyk|first8=Damian|last9=Jensen|first9=Lars Juhl|last10=Gilbert|first10=M. Thomas P.|last11=Willerslev|first11=Eske|year=2011|title=Pre-Clovis Mastodon Hunting 13,800 Years Ago at the Manis Site, Washington|journal=Science|volume=334|issue=6054|pages=351–353|doi=10.1126/science.1207663|pmid=22021854 |bibcode=2011Sci...334..351W }}</ref>

In 2017, Steven R. Holen et al. published an article arguing that the [[Cerutti Mastodon site]], located in [[San Diego County]] in California, is an archeological site involving ''M. americanum'' that dates to approximately 130,000 years ago. If true, they stated, the site would imply evidence of now-extinct species of ''[[Homo]]'' in North America during the [[Marine Isotope Stage 5]] (MIS 5e) temporal range of the early late Pleistocene.<ref>{{cite journal|last1=Holen|first1=Steven R.|last2=Deméré|first2=Thomas A.|last3=Fisher|first3=Daniel C.|last4=Fullagar|first4=Richard|last5=Paces|first5=James B.|last6=Jefferson|first6=George T.|last7=Beeton|first7=Jared M.|last8=Cerutti|first8=Richard A.|last9=Rountrey|first9=Adam N.|last10=Vescera|first10=Lawrence|last11=Holen|first11=Kathleen A.|year=2017|title=A 130,000-year-old archaeological site in southern California, USA|journal=Nature|volume=544|issue=7651 |pages=479–483|doi=10.5066/F7HD7SW7|pmid=28447646 }}</ref> The proposal was highly controversial, as many archeologists were skeptical about the claim that the bones of ''M. americanum'' were broken by hominins, and alternate explanations have been offered.<ref name="site"/> For instance, in the same year the article was published, Gary Haynes expressed concern of it being published in the journal ''[[Nature (journal)|Nature]]'' due to how highly prolific it is. Reporters from print presses and digital media published reactions of the article from various North American archeologists, with [[Donald K. Grayson]] stating that it was astonishingly bad, [[Jon M. Erlandson]] arguing that the site was non-credible, and various other archeologists arguing that the claim is insufficiently supported. Haynes pointed out that the article's claim was "extraordinary" and must therefore be met with rigorous skepticism. He wrote that there were no traces of archeological structures typically built by archaic species of ''Homo'' (i.e. ''[[H. erectus]]'', [[Neanderthal]]s, or [[Denisovan]]s) in the Cerutti site. Additionally, he brought up the possibilities of the fossil bones being affected by sediment pressures or damage done by earth-moving construction equipments despite the original authors denying the latter possibility.<ref>{{cite journal|last=Haynes|first=Gary|year=2017|title=The Cerutti Mastodon|journal=PaleoAmerica|volume=3|issue=3|pages=196–199|doi=10.1080/20555563.2017.1330103}}</ref>

Multiple [[petroglyph]]s suggested to have depicted prehistoric proboscideans in North America like mastodons are known within the United States, but they are either fraudulent or depict entities other than mastodons. As a result, suggested rock art of mammoths and mastodons within North America are not sufficiently credible.<ref>{{cite journal|last=Bednarik|first=Robert G.|year=2014|title=Pleistocene Palaeoart of the Americas|journal=Arts|volume=3|number=2|pages=190–206|doi=10.3390/arts3020190|doi-access=free}}</ref>

== Extinction ==
[[File:United States megafauna human SPDs.webp|thumb|left|Summed probability distributions (SPDs) of ''[[Mammuthus]]'', ''Mammut'', ''[[Nothrotheriops]]'', ''[[Equus (genus)|Equus]]'', ''[[Smilodon]]'', and humans in the latest Pleistocene of the United States]]
''Mammut'', or more specifically the American mastodon, experienced an initial decline in geographical range when it was extirpated from the northernmost ranges of North America ~75,000 years ago. ''Mammut'' initially occupied the region during the [[Last Interglacial]] (~125,000-75,000 years ago) back when suitable forested habitats were present there but was subsequently extirpated in correlation with environmental changes from the [[Wisconsin glaciation]] (MIS 4). The local extirpation, occurring long before human arrival, caused the mastodon range to be limited to areas south of North American ice sheets. The steppe-tundra faunas thrived there during the event whereas boreal forest-adapted faunas underwent declines.<ref>{{cite journal|last1=Zazula|first1=Grant D.|last2=MacPhee|first2=Ross|last3=Metcalfe|first3=Jessica|last4=Reyes|first4=Alberto V.|last5=Brock|first5=Fiona|last6=Druckenmiller|first6=Patrick S.|last7=Groves|first7=Pamela|last8=Harington|first8=C. Richard|last9=Hodgins|first9=Gregory|last10=Kunz|first10=Michael L.|last11=Longstaffe|first11=Fred John|last12=Mann|first12=Dan|last13=McDonald|first13=H. Gregory|year=2014|title=American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change|journal=Proceedings of the National Academy of Sciences|volume=111|issue=52|pages=18460–18465 |doi=10.1073/pnas.1416072111|doi-access=free |pmid=25453065 |pmc=4284604|bibcode=2014PNAS..11118460Z }}</ref><ref name="arctic"/> The trend of recolonization and extirpation appears to have had been a recurring trend in the Pleistocene correlated with repeated returns of forests and wetlands, but what is unclear is why faunas that were able to repeatedly recolonize northern North America during previous interglacial periods were unable to do so again after the [[Last Glacial Maximum]].<ref name="genomes"/>

The latest Pleistocene of North America records a [[Late Pleistocene extinctions|large extinction phase]] that resulted in the disappearances of over 30 genera of mammals, the majority of which are considered "megafauna" (~{{cvt|45|kg}} or larger). ''Mammut'' was one of the many genera recorded within North America whose extinction causes are currently unresolved.<ref>{{cite journal|last=Meltzer|first=David J.|year=2020|title=Overkill, glacial history, and the extinction of North America's Ice Age megafauna|journal=Proceedings of the National Academy of Sciences|volume=117|issue=46|pages=28555–28563|doi=10.1073/pnas.2015032117|doi-access=free |pmid=33168739 |pmc=7682371|bibcode=2020PNAS..11728555M }}</ref> During the latest Pleistocene of North America, two major events occurred: the development of Clovis culture from 13,200 to 12,800 years ago and the onset of the [[Younger Dryas]] cold phase from 12,900 to 11,700 years ago.<ref name="stuart">{{cite book|last=Stuart|first=Anthony J.|title=Vanished Giants: The Lost World of the Ice Age|chapter=Chapter 6. North America: mastodon, ground sloths, and sabertooth cats|date=August 20, 2022 |publisher=University of Chicago Press|pages=67–112 |isbn=978-0-226-82403-1}}</ref> The extinctions of mammalian megafauna in North America are particularly high akin to those of South America and Australia rather than Eurasia and Africa.<ref name="debate">{{cite journal|last1=Koch|first1=Paul L.|last2=Barnosky|first2=Anthony D.|year=2006|title=Late Quaternary Extinctions: State of the Debate|journal=Annual Review of Ecology, Evolution, and Systematics|volume=37|pages=215–250|doi=10.1146/annurev.ecolsys.34.011802.132415}}</ref> As a result, the extinctions that occurred in the latest Pleistocene of North America have been mainly attributed to human hunting, climate change, or some combination of the two (there are alternate but lesser-supported hypotheses). Many researchers have struggled to explained the North American extinctions, with both human hunting and climate change explanations alone being challenged.<ref>{{cite journal|last=Scott|first=Eric|year=2010|title=Extinctions, scenarios, and assumptions: Changes in latest Pleistocene large herbivore abundance and distribution in western North America|journal=Quaternary International|volume=217|issue=1–2|pages=225–239|doi=10.1016/j.quaint.2009.11.003|bibcode=2010QuInt.217..225S }}</ref> In recent years, research has shifted towards studying the extinctions of North American faunas by individual taxon and/or region rather as a homogenous group. The results vary in regions such as the northeast, with some authors suggesting that there was minimal evidence for Clovis hunting being the major factor behind proboscidean population drops and some others arguing that environmental shifts prior to human arrival were not detrimental enough to the proboscideans.<ref>{{cite journal|last1=Boulanger|first1=Matthew T.|last2=Lyman|first2=R. Lee|year=2014|title=Northeastern North American Pleistocene megafauna chronologically overlapped minimally with Paleoindians|journal=Quaternary Science Reviews|volume=85|pages=35–46|doi=10.1016/j.quascirev.2013.11.024|bibcode=2014QSRv...85...35B }}</ref><ref>{{cite journal|last1=Feranec|first1=Robert S.|last2=Kozlowski|first2=Andrew|year=2016|title=Implications of a Bayesian radiocarbon calibration of colonization ages for mammalian megafauna in glaciated New York State after the Last Glacial Maximum|journal=Quaternary Research|volume=85|issue=2|pages=262–270|doi=10.1016/j.yqres.2016.01.003|bibcode=2016QuRes..85..262F }}</ref>

Paul L. Koch and Anthony D. Barnosky in 2006 suggested that ''Mammuthus'' was well-associated with archeological sites of North America. In comparison, ''Mammut'' and the peccary ''[[Platygonus]]'' were far less frequently associated with human sites, potentially suggesting that Paleoindians hunted them less than mammoths. They stated that the current understanding of ''Mammut'' associations with humans could shift if the supposed butchery sites were better understood while that of ''Platygonus'' is stable and therefore unlikely to change.<ref name="debate"/> In 2018, Jack M. Broughton and Elic M. Weitzel calculated populated dynamics of some of the North American late Pleistocene megafauna based on summed probability distributions (SPDs) using calibrated [[radiocarbon date]]s. They determined based on the data that the declines of ''Mammuthus'', ''Equus'', and ''Smilodon'' were correlated with Clovis culture hunting while ''Mammut'' and the [[nothrotheriid]] ground sloth ''[[Nothrotheriops]]'' did not exhibit any significant population bust until after Clovis culture and during the Younger Dryas at ~12,650 years ago. They concluded that the declines of megafauna are of mixed causes and that the extinction processes and causes therefore vary by individual taxon and region.<ref>{{cite journal|last1=Broughton|first1=Jack M.|last2=Weitzel|first2=Elic M.|year=2018|title=Population reconstructions for humans and megafauna suggest mixed causes for North American Pleistocene extinctions|journal=Nature Communications|volume=9|number=5441|page=5441 |doi=10.1038/s41467-018-07897-1|pmid=30575758 |pmc=6303330|bibcode=2018NatCo...9.5441B }}</ref>

Of note is that there is a recorded latest survival of the American mastodon in the early [[Holocene]]. The Overmyer Mastodon individual, recovered from northern Indiana with 41-48% complete remains recovered, exhibits no evidence of weathering or gnawing by other animals. The individual dates from 11,795 to 11,345 years Before Present for a median of 11,576 calibrated years BP, therefore having a secure calibrated radiocarbon date dating to the early Holocene unlike most other extinct North American genera of the terminal Pleistocene. Neal Woodman and Nancy Beavan Athfield stressed that although the early Holocene survival of the species does not eliminate the possibilities that Clovis hunters and/or Younger Dryas impacted their populations in the long term, its survival meant that the genus was not immediately brought to extinction by either factor.<ref>{{cite journal|last1=Woodman|first1=Neal Woodman|last2=Athfield|first2=Nancy Beavan|year=2009|title=Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America|journal=Quaternary Research|volume=72|issue=3|pages=359–363|doi=10.1016/j.yqres.2009.06.009|bibcode=2009QuRes..72..359W }}</ref><ref name="stuart"/>

== Cultural significance ==
[[File:Winsor McCay 1922-03-19 Oblivion's Cave.jpg|thumb|Political cartoon "Oblivion's Cave—Step Right In, Please" by [[Winsor McCay]], 1922]]
Late Pleistocene proboscideans of the Americas such as the American mastodon could have been recognized in Native American oral histories, but they are unlikely to have referenced any specific species. Typically, they may have been depicted in Native American oral history as aggressive and antagonistic beasts.<ref>{{cite thesis|type=MA|last=Landol|first=Nicholas|year=2022|title=The Role of the Pleistocene in Native American Oral Traditions|chapter=Chapter 4: Analysis|publisher=Binghamton University|pages=21–53|url=https://www.researchgate.net/publication/368392074}}</ref> Mastodons may have played ancient roles in [[Indigenous peoples of the Pacific Northwest Coast|Native American cultures of the Pacific Northwest]]. In 1987, Carl E. Gustafson recovered fossil evidence of a late Pleistocene mastodon far away from where the species would typically roam, the radiocarbon dating confirming a date of about 13,800 years ago. The local tribal members identified the remains as being of game pieces for [[slahal]], a gambling game for dispute settlements and entertainment.<ref>{{cite news|last1=Nose|first1=Renee Roman|year=2012|title=An Oral History of the Ancient Game of Sla-Hal: Man Versus Animals|work=ICT News|url=https://ictnews.org/archive/an-oral-history-of-the-ancient-game-of-sla-hal-man-versus-animals|archive-url=https://web.archive.org/web/20230425025130/https://ictnews.org/archive/an-oral-history-of-the-ancient-game-of-sla-hal-man-versus-animals|archive-date=25 April 2023|access-date=20 February 2024}}</ref> The bone sticks, carved from mastodon bones, are not easily interpretable archeologically, but tribal members saw the recovery of the items as evidence of the endurance of ancient cultural practices like slahal.<ref>{{cite news|last=Mapes|first=Lynda V.|year=2012|title=Tribal gathering celebrates unifying culture of an ancient game|work=The Seattle Times|url=https://www.seattletimes.com/seattle-news/tribal-gathering-celebrates-unifying-culture-of-an-ancient-game/|archive-url=https://web.archive.org/web/20210922002712/https://www.seattletimes.com/seattle-news/tribal-gathering-celebrates-unifying-culture-of-an-ancient-game/|archive-date=22 September 2021|access-date=20 February 2024}}</ref>

The American mastodon had long been a stand-in within the United States for American nationalism since early American history,<ref name="peale2"/> and Thomas Jefferson was famously known for having hoped that the [[Lewis and Clark Expedition]] would eventually yield evidence of living mastodons in the western frontier of the United States.<ref>{{cite journal|last=Thomson|first=Keith|year=2011|title=Jefferson's old bones: did the so-called father of American vertebrate paleontology believe in fossils?|journal=American Scientist|volume=99|issue=3|doi=10.1511/2011.90.200 |url=https://www.americanscientist.org/article/jeffersons-old-bones}}</ref><ref>{{cite journal|last=Currie|first=Philip J.|year=2023|title=Celebrating dinosaurs: their behaviour, evolution, growth, and physiology|journal=Canadian Journal of Earth Sciences|volume=60|number=3|pages=263–293 |doi=10.1139/cjes-2022-0131|bibcode=2023CaJES..60..263C }}</ref> It was a defining symbol of museums according to Brett Barney as evident by a mention of it by [[Walt Whitman]] in a passage of the 1855 poem "[[Song of Myself]]."<ref>{{cite book|editor-last=Kummings|editor-first=Donald D.|last=Barney|first=Brett|year=2006|title=A Companion to Walt Whitman|chapter=Chapter 15: Nineteenth-century Popular Culture|publisher=Blackwell Publishing|pages=233–256|url=https://digitalcommons.unl.edu/libraryscience/111/}}</ref>

[[File:Nova Scotia DSC07369 - Mastodon Ridge (35913143965).jpg|thumb|left|Mastodon replica at the [[Mastodon Ridge]] park in [[Stewiacke]], [[Nova Scotia]], Canada]]
The mastodon became the subject of a Michigan political campaign in 2000 when [[Washtenaw Community College]] geology instructor David P. Thomas Sr. aimed to make it the state fossil of Michigan. He, assisted by the [[Slauson Middle School (Ann Arbor, Michigan)|Slauson Middle School]] science teacher Jeffrey Bradley, was sponsored by the state senator [[Thaddeus McCotter]], arranged petition drives that collected thousands of signatures, and attended state hearings. Bradley's students participated in the "Mastodon for Michigan" campaign, which built a life-sized replica out of paper and raised $1,000 for the [[University of Michigan Museum of Natural History]] to built a mastodon exhibit. In 2002, the mastodon became the state fossil, making it the fourteenth [[Lists of United States state symbols|state symbol]].<ref>{{cite web|year=2002|title=STATE FOSSIL: MASTODON|work=Michigan Legislature|url=https://www.legislature.mi.gov/documents/2001-2002/billanalysis/House/htm/2001-HLA-0397-a.htm|archive-url=https://web.archive.org/web/20240129001956/https://www.legislature.mi.gov/documents/2001-2002/billanalysis/House/htm/2001-HLA-0397-a.htm|archive-date=29 January 2024|access-date=21 February 2024}}</ref><ref>{{cite web|title=Mastodon|work=State Symbols USA|date=10 October 2014 |url=https://statesymbolsusa.org/symbol-official-item/michigan/state-dinosaur-fossil/mastodon|archive-url=https://web.archive.org/web/20231001081701/https://statesymbolsusa.org/symbol-official-item/michigan/state-dinosaur-fossil/mastodon|archive-date=1 October 2023|access-date=21 February 2024}}</ref> Similarly, the mastodon became the state fossil of Indiana as recently as 2022 due to House Bill 1013, authored by the representative [[Randy Frye]], passing unanimously.<ref>{{cite news|title=Indiana lawmakers name mastodon as first state fossil|work=WFYI|url=https://www.wfyi.org/news/articles/indiana-lawmakers-name-mastodon-as-first-state-fossil|archive-url=https://web.archive.org/web/20230922112045/https://www.wfyi.org/news/articles/indiana-lawmakers-name-mastodon-as-first-state-fossil|archive-date=22 September 2023|access-date=21 February 2024}}</ref>

In January 2024, Indiana senator [[Mike Braun]] and Michigan senator [[Gary Peters]] introduced a bipartisan bill to make the mastodon the US national fossil is what is called the "National Fossil Act." Section 1 aims to define the bill's name, Section 2 would investigate the roles of the mastodon in American public life, and Section 3 would designate it as the national fossil under [[Title 36 of the United States Code]]. Peters justified that the mastodon represents a unique aspect of Michigan's history and American history, stating that he hoped that its establishment as the national fossil would preserve the histories and encourage new generations of scientists and other researchers to pursue their goals.<ref>{{cite news|title=Senators Braun and Peters Introduce Bill to Name Mastodon America's National Fossil|work=Mike Braun: U.S. Senator Indiana|url=https://www.braun.senate.gov/news/press-releases/25802-2/|archive-url=https://web.archive.org/web/20240220235406/https://www.braun.senate.gov/news/press-releases/25802-2/|archive-date=20 February 2024|access-date=21 February 2024}}</ref><ref>{{cite news|last=Davidson|first=Kyle|year=2024|title=Peters introduces bipartisan proposal to designate the first national fossil|work=Michigan Advance|url=https://michiganadvance.com/briefs/peters-introduces-bipartisan-proposal-to-designate-the-first-national-fossil/|archive-url=https://web.archive.org/web/20240127193610/https://michiganadvance.com/briefs/peters-introduces-bipartisan-proposal-to-designate-the-first-national-fossil/|archive-date=27 January 2024|access-date=21 February 2024}}</ref>

Located in the [[Mastodon Ridge]] park in the Canadian town of [[Stewiacke]], [[Nova Scotia]] is a large-sized replica of a mastodon based on a skeleton recovered from Nova Scotia. It was sculpted as a clay model, has a weight of ~{{cvt|1400|kg}}, is {{cvt|3.5|m}} in shoulder height, and measures {{cvt|7.5|m}} long. The sculpture took about 8 weeks to be constructed and was sent to the Mastodon Ridge in January 1995.<ref>{{cite web|title=Replica|work=Mastodon Ridge|url=https://mastodonridge.ca/mastodon/replica/|archive-url=https://web.archive.org/web/20240116153106/https://mastodonridge.ca/mastodon/replica/|archive-date=16 January 2024|access-date=21 February 2024}}</ref>

The name "mastodon" was adopted in different contexts within the United States. For instance, [[4-8-0]] [[locomotive]]s of the late 19th century were originally named "''[[Mastodon (steam locomotive)|Mastodons]]''" before the name was eventually replaced with "12-wheeler." The name was a reference to the American mastodon. The [[4-10-0]] locomotive later became known also as "''Mastodon''."<ref>{{cite book|last=Morrison|first=Tom|year=2018|title=The American Steam Locomotive in the Twentieth Century|chapter=Chapter 4: Locomotive Construction, 1895–1905|publisher=McFarland|pages=133–182}}</ref><ref>{{cite journal|last=Gaskell|first=G.H.|year=1952|title=The Origin of Locomotive Class Names|journal=The Railway and Locomotive Historical Society Bulletin|number=87|pages=83–95|jstor=43517676 |url=https://www.jstor.org/stable/43517676}}</ref> In the 1993-1995 show ''[[Mighty Morphin Power Rangers]]'', the Black Ranger [[Zack Taylor]] had the mastodon ability and controlled the Mastodon Dinozord machine.<ref>{{cite thesis|type=MA|last=Wilhelmi|first=Cynthia J.|year=1996|title=The content of the Mighty Morphin Power Rangers as the source of antisocial and prosocial learning|publisher=University of Nebraska at Omaha|url=https://digitalcommons.unomaha.edu/studentwork/3018/}}</ref> The name "Mastodon" was also adopted by a [[heavy metal music|heavy metal]] band when guitarist [[Bill Kelliher]] was asked by the guitarist-singer [[Brent Hinds]] asked him about the name of the "fossil elephant" after seeing his tattoo of a [[Bantha]] skull from the [[Star Wars]] franchise, in which the members then agreed to it being the [[Mastodon (band)|band's name]].<ref>{{cite web|last=Marchese|first=David|year=2010|title=How They Became... Mastodon|work=Spin|url=https://www.spin.com/2010/04/how-they-became-mastodon/|archive-url=https://web.archive.org/web/20220629191437/https://www.spin.com/2010/04/how-they-became-mastodon/|archive-date=29 June 2022|access-date=21 February 2024}}</ref> "Mastodon" is also the name of a blogging [[social network]] site that also acquired its name from the extinct proboscidean species.<ref>{{cite magazine|last=Perrigo|first=Billy|year=2020|title=Thousands Have Joined Mastodon Since Twitter Changed Hands. Its Founder Has a Vision for Democratizing Social Media|magazine=Time|url=https://time.com/6229230/mastodon-eugen-rochko-interview/|archive-url=https://web.archive.org/web/20240121220657/https://time.com/6229230/mastodon-eugen-rochko-interview/|archive-date=21 January 2024|access-date=21 February 2024}}</ref>

==See also==
{{Portal|Paleontology}}
*[[Coats–Hines site]]
*[[List of museums and colleges with mastodon fossils on display]]
*[[Manis Mastodon site]]
*[[Snowmastodon site]]
*[[Cerutti Mastodon site]]
*[[Big Bone Lick State Park]]

==References==
{{Reflist}}

==External links==
{{Wikispecies|Mammut}}
{{Commons category|Mammut}}
{{EB1911 poster|Mastodon}}
* [https://web.archive.org/web/20080706165529/http://www.rmsc.org/MuseumAndScienceCenter/exhibits/GlaciersAndGiants/ The Rochester Museum of Science – Expedition Earth Glaciers & Giants]
* [http://www.museum.state.il.us/exhibits/larson/mammut.html Illinois State Museum – Mastodon]
* [https://web.archive.org/web/20170410210536/http://www.calvin.edu/academic/geology/mastodon/calvin_c.htm Calvin College Mastodon Page]
* [http://www.amnh.org/exhibitions/permanent-exhibitions/fossil-halls/paul-and-irma-milstein-hall-of-advanced-mammals/warren-mastodon American Museum of Natural History – Warren Mastodon]
* [https://web.archive.org/web/20090618001229/http://www.bbc.co.uk/nature/wildfacts/factfiles/3004.shtml BBC Science and Nature:Animals – American mastodon Mammut americanum]
* [http://news.bbc.co.uk/1/hi/world/europe/6913366.stm BBC News – Greek mastodon find 'spectacular']
* [https://web.archive.org/web/20060424085647/http://www.mostateparks.com/mastodon.htm Missouri State Parks and Historic Sites – Mastodon State Historic Site]
* [http://www.slfp.com/Mastodon.htm Saint Louis Front Page – Mastodon State Historic Site]
* [http://www.earlham.edu/joseph-moore-museum/history/randolph-mastodon Story of the Randolph Mastodon (Earlham College)] {{Webarchive|url=https://web.archive.org/web/20151220203859/http://www.earlham.edu/joseph-moore-museum/history/randolph-mastodon/ |date=2015-12-20 }}
* [http://www.flmnh.ufl.edu/natsci/vertpaleo/aucilla/arpp01.htm The Florida Museum of Natural History Virtual Exhibit – The Aucilla River Prehistory Project:When The First Floridians Met The Last Mastodons]
* [http://westerncentermuseum.org Western Center for Archaeology & Paleontology, home of the largest mastodon ever found in the Western United States]
* [http://www.smithsonianmag.com/science-nature/Mammoths-and-Mastodons-All-American-Monsters.html Smithsonian Magazine Features Mammoths and Mastodons]
* [https://www.photospherix.com/3d-view/mastodon-skull/ 360 View of a Mastodon Skull from Indiana State Museum]
* 3-D Viewers of [http://umorf.ummp.lsa.umich.edu/wp/wp-content/3d/bonePicker.html?name=Buesching male] and [https://umorf.ummp.lsa.umich.edu/wp/wp-content/3d/viewer.html?name=1335&extension=ctm female] mastodon skeletons at the University of Michigan [https://umorf.ummp.lsa.umich.edu/wp/mammutidae2/ Mammutidae digital fossil repository]
* ''[[Scientific American]]'', "[https://books.google.com/books?id=6ok9AQAAIAAJ The Chicago Mastodon]", 18 September 1880, p.&nbsp;175

{{Proboscidea Genera}}
{{Taxonbar|from=Q192272}}
{{Authority control}}

[[Category:Mastodons| ]]
[[Category:Extinct animals of Canada]]
[[Category:Fossil taxa described in 1799]]
[[Category:Mammutidae]]
[[Category:Messinian first appearances]]
[[Category:Miocene mammals of North America]]
[[Category:Miocene proboscideans]]
[[Category:Paleontology in Michigan]]
[[Category:Pleistocene extinctions]]
[[Category:Pleistocene mammals of North America]]
[[Category:Pleistocene proboscideans]]
[[Category:Pliocene mammals of North America]]
[[Category:Pliocene proboscideans]]
[[Category:Ringold Formation Miocene Fauna]]
[[Category:Symbols of Indiana]]
[[Category:Symbols of Michigan]]