PBDB Taxon

Basic info	Taxonomic history	Classification	Included Taxa
Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Archaeotherium

Mammalia - Entelodontidae

Taxonomy

Archaeotherium was named by Leidy (1850).

It was synonymized subjectively with Entelodon by Leidy (1853); it was synonymized subjectively with Elotherium by Leidy (1857) and Leidy (1873).

It was assigned to Entelodontidae by Leidy (1850), Peterson (1909), Scott (1940), Galbreath (1953), Wood (1960), Russell (1980), Carroll (1988), Effinger (1998), Thewissen et al. (2001), Foss (2007), Vislobokova (2008) and Spaulding et al. (2009).

Species

A. calkinsi, A. caninus, A. coarctatum (syn. Elotherium arctatum), A. crassum, A. imperator, A. marshi, A. mortoni (syn. Elotherium clavum, Rhinoceros americanus, Arctodon vetustum, A. robustum), A. palustris, A. scotti, A. superbum, A. trippensis, A. wanlessi, Choerodon calkinsi, Eotherium abeli, Eotherium markgrafi

Synonyms

Choerodon was named by Troxell (1920).

It was synonymized subjectively with Archaeotherium by Caroll (1988) and Foss and Fremd (1998).

It was assigned to Entelodontidae by Troxell (1920), Effinger (1998) and Vislobokova (2008).
Elotherium imperator was named by Leidy (1873). It is a 3D body fossil.

It was recombined as Entelodon imperator by Cope and Matthew (1915); it was considered a nomen vanum by Peterson (1909) and Troxell (1920); it was considered a nomen dubium by Foss and Fremd (1998).
Eotherium was named by Leidy (1853).

It was considered a nomen dubium by Osborn (1929); it was synonymized subjectively with Archaeotherium by Scott (1940).

It was assigned to Mammalia by Leidy (1853); and to Titanotheriidae by Palmer (1904).

Synonymy list

Year	Name and author
1850	Archaeotherium Leidy
1853	Eotherium Leidy p. 392
1873	Elotherium imperator Leidy p. 217
1902	Elotherium imperator Hay p. 655
1904	Eotherium Palmer p. 265
1909	Archaeotherium Peterson
1915	Entelodon imperator Cope and Matthew pp. Plate CIXa
1920	Choerodon Troxell p. 441
1940	Archaeotherium Scott p. 379 figs. Plates XXXVIII, XL, XLII, XLIII
1953	Archaeotherium Galbreath
1960	Archaeotherium Wood
1980	Archaeotherium Russell p. 5
1988	Archaeotherium Carroll
1998	Archaeotherium Effinger p. 378
1998	Choerodon Effinger p. 378
2001	Archaeotherium Thewissen et al. p. suppl.
2007	Archaeotherium Foss p. 126
2008	Archaeotherium Vislobokova
2008	Choerodon Vislobokova
2009	Archaeotherium Spaulding et al. p. e7062

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
—	Osteichthyes	()
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
subclass	Synapsida
—	Therapsida	()
infraorder	Cynodontia	()
—	Mammaliamorpha

Rank	Name	Author
—	Mammaliaformes
class	Mammalia
—	Theriamorpha	(Rowe 1993)
—	Theriiformes	()
—	Trechnotheria
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Boreoeutheria
—	Laurasiatheria
—	Scrotifera
—	Euungulata
—	Artiodactylamorpha
—	Artiodactyla	()
superfamily	Entelodontoidea	Lydekker 1883
family	Entelodontidae	Lydekker 1883
genus	Archaeotherium

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

G. †Archaeotherium Leidy 1850

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†Archaeotherium calkinsi Sinclair 1905

†Archaeotherium caninus Troxell 1920

†Archaeotherium coarctatum Cope 1889

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Invalid names: Elotherium arctatum Osborn 1891 [synonym]

†Archaeotherium crassum Marsh 1873

†Archaeotherium marshi Troxell 1920

†Archaeotherium mortoni Leidy 1850

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†Archaeotherium clavus darbyi Troxell 1920

Invalid names: Archaeotherium robustum Leidy 1852 [synonym], Arctodon vetustum Leidy 1852 [synonym], Elotherium clavum Marsh 1893 [synonym], Rhinoceros americanus Leidy 1852 [synonym]

†Archaeotherium palustris Schlaikjer 1935

†Archaeotherium scotti Sinclair 1922

†Archaeotherium trippensis Skinner et al. 1968

†Archaeotherium wanlessi Sinclair 1922

Invalid names: Archaeotherium imperator Leidy 1873 [nomen dubium], Archaeotherium superbum Leidy 1868 [nomen dubium], Choerodon Troxell 1920 [synonym], Eotherium Leidy 1853 [synonym]

Diagnosis

Reference	Diagnosis
L. S. Russell 1980	Entelodonts of large but not largest size. Diastema present between first and second premolars and to a lesser extent between second and third premolars; premolars double-rooted except P^, which is triple-rooted, and P\ which may be single-rooted; P"* trianguloid, due to anterad bulge of anterolabial portion; lower molars with trigonid higher than talonid. Lower margin of jugals produced as a long, flat process, projecting ventrolaterad and more or less posterad. Mandible with sloping symphysis; prominent mental process projecting ventrolaterad from ventral margin of ramus below canine root; most but not all species have a second, similar process below P4; angular margin broadly rounded, projecting ventrad and somewhat laterad, not thickened.

Measurements

No measurements are available

Composition:

phosphaticsubp

Environment:

terrestrialo

Locomotion:

actively mobilec

Life habit:

ground dwellingf

Diet:

omnivoref

Reproduction:

viviparoussubc

Created:

2005-08-31 14:31:11

Modified:

2005-08-31 16:31:11

Source: f = family, o = order, subc = subclass, c = class, subp = subphylum

References: Carroll 1988, Effinger 1998, Hendy et al. 2009, Nowak 1999, Lillegraven 1979

Age range: base of the Chadronian to the top of the Arikareean or 37.20000 to 18.50000 Ma

Collections (59 total)

Time interval	Ma	Country or state	Original ID and collection number
Chadronian	37.2 - 33.9	Canada (Saskatchewan)	A. coarctatum (16893 16919) A. sp. (16979) Elotherium arctatum, Menodus americanus (101961)
Chadronian	37.2 - 33.9	USA (Nebraska)	A. crassum (17018) A. mortoni (16918 16930) A. sp. (16917 16940)
Chadronian	37.2 - 33.9	USA (Wyoming)	A. coarctatum (16962 16963 16964 16965) A. mortoni (16922) A. sp. (16911 17011 17045)
Chadronian	37.2 - 33.9	USA (Texas)	A. mortoni (16894 16931)
Chadronian	37.2 - 33.9	USA (Colorado)	A. crassum, A. mortoni (16977)
Chadronian	37.2 - 33.9	USA (South Dakota)	A. coarctatum, A. mortoni (16885) A. crassum (16978) A. marshi (16969) A. scotti (17006)
Middle Chadronian - Late/Upper Chadronian	37.2 - 33.9	USA (Colorado)	A. sp. (156988)
Orellan	33.9 - 33.3	USA (Oregon)	Entelodon sp. (17070)
Orellan	33.9 - 33.3	USA (South Dakota)	A. mortoni (17133 17174 17296) A. mortoni, A. wanlessi (17094 17180) A. sp. (17089 17102 17188 163487) A. sp., A. mortoni (17092) A. wanlessi (180329) Elotherium mortoni (17141 17142 17153)
Orellan	33.9 - 33.3	USA (Colorado)	A. mortoni (17081 17082)
Orellan	33.9 - 33.3	USA (Nebraska)	A. mortoni (17098 17175)
Orellan	33.9 - 33.3	USA (North Dakota)	A. mortoni (17101)
Orellan	33.9 - 33.3	USA (Wyoming)	A. mortoni, A. palustris (17117)
Orellan	33.9 - 33.3	Canada (Saskatchewan)	A. mortoni (17055)
Whitneyan	33.3 - 30.8	USA (Oregon)	A. caninus (17349)
Geringian	30.8 - 26.3	USA (Oregon)	A. sp. (17508 17537 93078)
Arikareean	29.5 - 18.5	USA (Nebraska)	A. sp. (17514)
Arikareean	29.5 - 18.5	USA (Oregon)	Elotherium calkinsi, Entelodon imperator (189114) Elotherium imperator (180202)
Chattian	28.1 - 23.03	USA (Oregon)	A. caninus (93079) A. sp. (17603)
Monroecreekian	26.3 - 24.8	USA (South Dakota)	A. trippensis (17723)
Early/Lower Miocene	23.03 - 15.97	USA (Oregon)	Choerodon caninus (157001)
Early/Lower Hemingfordian	20.43 - 15.97	USA (Oregon)	A. caninus (17925)