PBDB Taxon

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Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Equini (horse)

Mammalia - Perissodactyla - Equidae

Taxonomy

Equini was named by Quinn (1955). It is extant. It was considered monophyletic by Hulbert (1988) and Prado and Alberdi (1996) and MacFadden (1998).

It was assigned to Equidae by Quinn (1957) and Hulbert (1988); and to Equinae by Lance (1950), Quinn (1955), Prothero and Schoch (1989), Baskin (1991), Kelly (1995), Prado and Alberdi (1996), MacFadden (1998), Alberdi et al. (2014), Ferrusquía-Villafranca et al. (2014) and Dos Santos Avilla et al. (2015).

Subtaxa

Allohippus, Boreohippidion, Calippus, Dinohippus, Equus (syn. Onager, Hippotigris, Haringtonhippus, Neohippus, Allozebra, Sterrohippus, Asinus, Kolpohippus, Kraterohippus, Tomolabis, Dolichohippus, Equus (Grevya), Equus (Megacephalon), Equus (Ludolphozecora)), Equus proversus, Heteropliohippus, Hippidion (syn. Parahipparion, Onohippidium, Onohippidion), Parapliohippus, Plesippus, Pliohippina, Pliohippus, Protohippina, Protohippus (syn. Eoequus)

Synonyms

Pliohippus proversus was named by Merriam (1916). Its type specimen is UCMP 21330, a tooth (a superior molar, m1 or m2, of the left side), and it is a 3D body fossil.

It was recombined as Plesippus proversus by Matthew (1924), Hay (1930), Matthew and Stirton (1930), Russell and VanderHoof (1931), Gazin (1936), Schultz (1936) and Schultz (1937); it was recombined as Equus proversus by Stirton (1940); it was synonymized subjectively with Equus simplicidens by Savage (1951), Skinner et al. (1972) and Kurten and Anderson (1980); it was considered a nomen dubium by Winans (1989), Macdonald (1992), Kelly (1998) and Kelly and Secord (2011).

Synonymy list

Year	Name and author
1916	Pliohippus proversus Merriam
1918	Pliohippus proversus Osborn p. 170 figs. Text Figs. 137, 138
1924	Plesippus proversus Matthew p. 2
1930	Plesippus proversus Hay
1930	Plesippus proversus Matthew and Stirton
1931	Plesippus proversus Russell and VanderHoof
1936	Plesippus proversus Gazin
1936	Plesippus proversus Schultz
1937	Plesippus proversus Schultz
1940	Equus proversus Stirton p. 195
1950	Equini Lance
1955	Equini Quinn p. 42
1957	Equini Quinn p. 10
1988	Equini Hulbert, Jr.
1989	Equini Prothero and Schoch p. 532
1991	Equini Baskin p. 999
1995	Equini Kelly p. 3
1996	Equini Prado and Alberdi p. 676
1998	Equini MacFadden p. 549
2014	Equini Alberdi et al.
2014	Equini Ferrusquía-Villafranca et al. p. 204
2015	Equini Dos Santos Avilla et al. pp. 925909-3

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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
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Boreoeutheria
—	Laurasiatheria
—	Scrotifera
—	Euungulata
—	Panperissodactyla
superorder	Perissodactylamorpha
order	Perissodactyla	()
superfamily	Equoidea
family	Equidae
subfamily	Equinae
tribe	Equini
tribe	Equini

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.

Tr. Equini Quinn 1955 [horse]

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G. †Allohippus Kretzoi 1938

†Allohippus stenonis Cocchi 1867

†Equus stenonis mygdoniensis Koufos 1992

†Equus stenonis granatensis Bustos 1976

G. †Boreohippidion Dos Santos Avilla et al. 2015

†Boreohippidion galushai MacFadden and Skinner 1979

G. †Calippus Matthew and Stirton 1930

Subg. †Calippus (Calippus) Matthew and Stirton 1930

Subg. †Calippus (Grammohippus) Hulbert, Jr. 1988

†Calippus cerasinus Hulbert, Jr. 1988

†Calippus circulus Quinn 1955

†Calippus elachistus Hulbert, Jr. 1988

†Calippus hondurensis Olson and McGrew 1941

Invalid names: Calippus castilli Cope 1886 [synonym]

†Calippus maccartyi Hulbert, Jr. 1988

†Calippus martini Hesse 1936

Invalid names: Equus laparensis Quinn 1955 [synonym]

†Calippus placidus Leidy 1869

Invalid names: Calippus optimus Quinn 1955 [synonym]

†Calippus proplacidus Osborn 1918

Invalid names: Calippus francisi Hay 1924 [synonym]

†Calippus regulus Johnston 1937

Invalid names: Calippus anatinus Quinn 1955 [synonym]

G. †Dinohippus Quinn 1955

†Dinohippus interpolatus Cope 1893

†Dinohippus leardi Drescher 1941

†Dinohippus leidyanus Osborn 1918

Invalid names: Pliohippus edensis Frick 1921 [synonym]

†Dinohippus mexicanus Lance 1950

Invalid names: Equus (Dolichohippus) mesamexicanus Mooser 1973 [synonym], Hippotigris ocotensis Mooser 1958 [synonym], Protohippus muelleri Mooser 1964 [synonym]

†Dinohippus osborni Frick 1921

†Dinohippus spectans Cope 1880

†Dinohippus subvenus Quinn 1955

G. Equus Linnaeus 1758 [horse]

†Equus (Asinus) cumminsi Cope 1893

Subg. Equus (Hemionus) Stehlin and Graziosi 1935

Equus (Hemionus) hemionus Pallas 1775 [onager]

Subg. †Equus (Hesperohippus) Hibbard 1955

†Equus (Hesperohippus) mexicanus Hibbard 1955

Invalid names: Equus midlandensis Quinn 1957 [synonym], Onager oviedoi Mooser 1959 [synonym]

Subg. †Equus (Sussemionus) Eisenmann 2010

†Equus (Sussemionus) suessenbornensis Wüst 1901

Equus africanus Heuglin and Fitzinger 1866 [African wild ass]

Equus africanus africanus Heuglin and Fitzinger 1866 [Nubian wild ass]

Equus africanus somaliensis Noack 1884 [Somali wild ass]

Invalid names: Equus africanus somalicus Sclater 1884 [synonym]

Invalid names: Equus asinus aethiopicus Denman 1957 [synonym]

†Equus alaskae Winans 1989

Invalid names: Equus lambei Hay 1917 [synonym]

Equus asinus Linnaeus 1758 [donkey]

†Equus australis Moreno 1888

Equus caballus Linnaeus 1758 [horse]

Invalid names: Equus (Amerhippus) neogeus Lund 1840 [synonym], Equus hippagrus Smith 1841 [synonym]

Equus caballus ferus Boddaert 1785

†Equus calobatus Troxell 1915

†Equus capensis Broom 1909

†Equus cedralensis Alberdi et al. 2014

†Equus coliemensis Lazarev 1980

†Equus complicatus Leidy 1858

Invalid names: Equus americanus Leidy 1847 [replaced], Equus eous Cope 1895 [synonym], Equus major DeKay 1842 [synonym]

†Equus conversidens Owen 1869

Invalid names: Equus barcenaei Cope 1884 [synonym], Onager zoyatalis Mooser 1959 [synonym]

†Equus eisenmannae Qiu et al. 2004

†Equus excelsus Leidy 1858

Invalid names: Asinus aguascalentensis Mooser 1959 [synonym], Onager arellanoi Mooser 1959 [synonym], Onager hibbardi Mooser 1959 [synonym]

†Equus francisci Hay 1915

Invalid names: Equus (Asinus) calobatus Troxell 1915 [synonym], Equus arrelanoi Mooser 1958 [synonym], Equus quinni Slaughter et al. 1962 [synonym]

†Equus fraternus Leidy 1858

†Equus fromanius Repenning et al. 1995

†Equus giganteus Gidley 1901

†Equus holmesi Hay 1920

†Equus intermedius Cope 1895

†Equus intermedius Rütimeyer 1877

†Equus jubatus Hay 1927

†Equus laurentius Hay 1913

†Equus mexicanus Hibbard 1955

Invalid names: Equus occidentalis Leidy 1865 [synonym], Equus pacificus Leidy 1868 [synonym], Equus scotti Gidley 1900 [synonym]

†Equus nalaikhaensis Kuznetsova and Zhegallo 1996

†Equus nearcticus Blake 1863

†Equus nevadanus Hay 1927

†Equus niobrarensis Hay 1913

†Equus niobrarensis alaskae Winans 1989

Invalid names: Equus hatcheri Hay 1915 [synonym]

†Equus nobisi Pichardo 2004

†Equus pectinatus Cope 1901

Equus przewalskii Poliakov 1881 [Przewalski's horse]

†Equus pseudaltidens Hulbert, Jr. 1995

Invalid names: Onager altidens Quinn 1957 [replaced]

Equus quagga Boddaert 1785 [plains zebra]

Equus quagga borensis Lönnberg 1922

Equus quagga burchelli Gray 1824 [Burchell's zebra]

Equus quagga chapmani Layard 1865

Equus quagga crawshayi De Winton 1896

Equus quagga quagga Boddaert 1785

Equus quagga boehmi Matschie 1892

†Equus sanmeniensis Teilhard de Chardin and Piveteau 1930

†Equus santaeelenae Spillmann 1938

†Equus sivalensis Falconer and Cautley 1849

†Equus tabeti Arambourg 1970

†Equus yunnanensis Colbert 1940

Equus zebra Linnaeus 1758 [mountain zebra]

Equus zebra hartmannae Matschie 1898 [Hartmann's mountain zebra]

Invalid names: Equus matschiei Zukowsky 1924 [synonym], Equus penricei Thomas 1900 [synonym]

Equus zebra zebra Linnaeus 1758 [Cape mountain zebra]

Invalid names: Equus campestris Gray 1852 [synonym], Equus indica Trouessart 1898 [synonym], Equus montanus Burchell 1822 [synonym]

Invalid names: Allozebra Trumler 1961 [synonym], Asinus Gray 1822 [synonym], Asinus africanus aegyptiacus Heuglin and Fitzinger 1866 [synonym], Asinus asinus dianae Dollman 1935 [synonym], Dolichohippus Heller 1912 [synonym], Equus (Amerhippus) Hoffstetter 1950 [invalid subgroup], Equus (Parastilidequus) Mooser and Dalquest 1975 [invalid subgroup], Equus leidyi Hay 1913 [nomen vanum], Equus parastylidens Mooser 1959 [nomen dubium], Equus semiplicatus Cope 1893 [nomen dubium], Equus taeniopus Heuglin 1861 [nomen dubium], Equus zebra frederici Trouessart 1905 [synonym], Haringtonhippus Heintzman et al. 2017 [synonym], Hippotherium princeps Leidy 1890 [nomen dubium], Hippotigris Hamilton-Smith 1841 [synonym], Kolpohippus van Hoepen 1930 [synonym], Kraterohippus van Hoepen 1930 [synonym], Neohippus Abel 1913 [synonym], Onager Brisson 1762 [synonym], Sterrohippus van Hopen 1930 [synonym], Tomolabis Cope 1892 [synonym]

G. †Heteropliohippus Kelly 1995

†Heteropliohippus hulberti Kelly 1995

G. †Hippidion Owen 1869

†Hippidion angulatus Ameghino 1889

†Hippidion devillei Gervais 1855

Invalid names: Onohippidium bolivianum Philippi 1893 [synonym]

†Hippidion principale Lund 1846

Invalid names: Onohippidium munizi Moreno 1891 [synonym]

†Hippidion saldiasi Roth 1899

Subg. †Hippidium (Plagiohippus) Ameghino 1908

†Plagiohippus chapalmalensis Ameghino 1908

†Hippidium bonaerense Ameghino 1907

†Hippidium entrerianum Ameghino 1886

†Hippidium principale Lund 1846

Invalid names: Hippidion compressidens Ameghino 1889 [synonym]

Invalid names: Onohippidium Moreno 1891 [synonym], Parahipparion Ameghino 1904 [synonym]

G. †Parapliohippus Kelly 1995

†Parapliohippus carrizoensis Dougherty 1940

Invalid names: Merychippus tehachapiensis Buwalda and Lewis 1955 [synonym]

G. †Plesippus Matthew 1924

†Equus (Plesippus) crenidens Cope 1884

†Plesippus francescana Frick 1921

†Plesippus idahoensis Merriam 1918

†Plesippus simplicidens Cope 1892

Invalid names: Equus achates Hay and Cook 1930 [synonym], Equus pons Quinn 1958 [synonym], Equus shoshonensis Gidley 1930 [synonym], Equus tau Owen 1869 [synonym]

Subtr. Pliohippina Prado and Alberdi 1996

G. †Astrohippus Stirton 1940

†Astrohippus ansae Matthew and Stirton 1930

†Astrohippus stockii Lance 1950

Invalid names: Astrohippus albidens Mooser 1968 [synonym]

G. †Pliohippus Marsh 1874

Subg. †Pliohippus (Astrohippus) Stirton 1940

†Pliohippus (Astrohippus) stockii Lance 1950

Subg. †Pliohippus (Pliohippus) Stirton 1940

†Pliohippus (Pliohippus) mexicanus Lance 1950

†Pliohippus bakeri Azzaroli 1988

†Pliohippus coalingensis Merriam 1914

†Pliohippus fossulatus Cope 1893

Invalid names: Protohippus pachyops Cope 1893 [synonym]

†Pliohippus mirabilis Leidy 1858

Invalid names: Merychippus campestris Gidley 1907 [synonym]

†Pliohippus nobilis Osborn 1918

†Pliohippus pernix Marsh 1874

Invalid names: Pliohippus lullianus Troxell 1916 [synonym], Pliohippus robustus Marsh 1874 [synonym]

†Pliohippus potosinus Ferrusquía-Villafranca et al. 2014

†Pliohippus tantalus Merriam 1913

Invalid names: Pliohippus fairbanksi Merriam 1915 [synonym]

†Pliohippus tehonensis Merriam 1915

Invalid names: Pliohippus gracilis Marsh 1892 [nomen dubium]

G. †Protohippus Leidy 1858

Subg. †Protohippus (Calippus) Matthew and Stirton 1930

†Protohippus gidleyi Hulbert, Jr. 1988

†Protohippus parvulus Marsh 1868

†Protohippus perditus Leidy 1858

†Protohippus perditus secundus Osborn 1918

Invalid names: Eoequus wilsoni Quinn 1955 [synonym], Protohippus profectus Cope 1889 [synonym]

†Protohippus supremus Leidy 1869

Invalid names: Hippotigris clarendonensis Quinn 1955 [synonym], Hippotigris parastylus Quinn 1955 [synonym], Hippotigris sellardsi Quinn 1955 [synonym], Protohippus simus Gidley 1906 [synonym]

†Protohippus tantalus Merriam 1913

†Protohippus vetus Quinn 1955

Invalid names: Eoequus Quinn 1955 [synonym], Protohippus medius Cope 1892 [nomen dubium]

Invalid names: Equus proversus Merriam 1916 [nomen dubium], Protohippina Quinn 1955 [empty]

Diagnosis

Reference	Diagnosis
J. H. Quinn 1955	Upper teeth with heavy styles and deep valleys; pli protoloph usually present; protocones elongate, usually grooved and heeled, connected to protoselene throughout in late forms, partly unconnected in early forms; hypo- conal groove open or nearly so; lower teeth flattened transverse! y; parastylid present in early forms, lost in late forms; pli caballinid on any or all lower cheek teeth when present.

Measurements

No measurements are available

Composition:

phosphaticsubp

Environment:

terrestrialsubc

Locomotion:

actively mobilec

Life habit:

ground dwellingsubf

Diet:

grazersubf

Diet 2:

browsersubf

Reproduction:

viviparoussubc

Created:

2005-08-31 14:56:53

Modified:

2005-08-31 16:56:53

Source: subf = subfamily, subc = subclass, c = class, subp = subphylum

References: Carroll 1988, Hendy et al. 2009, Lillegraven 1979, Ji et al. 2002, MacFadden 1998, Nowak 1991

Age range

Maximum range based only on fossils: base of the Barstovian to the top of the Holocene or 16.30000 to 0.00000 Ma
Minimum age of oldest fossil (stem group age): 15.97 Ma

Collections (2114 total)

Time interval	Ma	Country or state	Original ID and collection number
Oldest occurrences
Miocene	23.03 - 5.333	Honduras (Lempira)	Calippus hondurensis (18723)
Miocene	23.03 - 5.333	USA (California)	Heteropliohippus hulberti (19456) Merychippus carrizoensis (19267 19294 19325) Merychippus intermontanus (19442) Merychippus tehachapiensis (19259) Pliohippus interpolatus (19370) Pliohippus osborni (19376) Pliohippus tehonensis (19148 19149) Protohippus sp. (19439) Stylonus carrizoensis (19344 19428)
Miocene	23.03 - 5.333	USA (Nevada)	Dinohippus sp. (18852 18853 18854 18855 18856 19049 19050 19051 19052 19055) Equini indet. (18857 18912) Pliohippus sp. (18885 18920 19040 19065) Pliohippus spectans (19129) Pliohippus tantalus (19125) Protohippus sp. (18836 18837)
Miocene	23.03 - 5.333	USA (Florida)	Calippus cerasinus (18542) Calippus hondurensis (18540) Calippus hondurensis, Calippus elachistus (18521) Merychippus sp. (18507) Protohippus gidleyi, Calippus cerasinus (18574)
Miocene	23.03 - 5.333	USA (South Dakota)	Equini indet. (18080) Equini indet., Pliohippus lullianus (18297) Pliohippus lullianus (18384 18388 18395) Pliohippus sp. (18038 18039 18318 18367 18368 18370 18392) Protohippus martini (18115) Protohippus sp. (18081 18084 18113 18182 18185 18389 18390)
Miocene	23.03 - 5.333	USA (Arizona)	Pliohippus sp. (19177 19178 19179 19360 19574)
Miocene	23.03 - 5.333	Honduras	Calippus hondurensis (18743) Pliohippus hondurensis (18751)
Miocene	23.03 - 5.333	USA (Colorado)	Pliohippus sp., Merychippus campestris (18310)
Miocene	23.03 - 5.333	USA (Texas)	Calippus cerasinus (18687) Calippus francisi, Merychippus circulus (18647) Calippus francisi, Merychippus perditus (18680) Calippus francisi, Merychippus vetus (18658) Calippus placidus, Calippus regulus (18371) Equidae indet. (18625 18671) Pliohippus pernix (18103) Protohippus perditus (18638)
Miocene	23.03 - 5.333	USA (Georgia)	Calippus sp. (18592)
Miocene	23.03 - 5.333	USA (Montana)	Pliohippus interpolatus (18997 19067 19068 19069) Pliohippus sp. (18812 18966) Protohippus sp. (18931)
Miocene	23.03 - 5.333	USA (Oklahoma)	Calippus martini (18105)
Miocene	23.03 - 5.333	USA (Nebraska)	Calippus sp. (18436) Pliohippus sp. (18213) Protohippus perditus (18354)
Miocene - Pliocene	23.03 - 2.588	South Africa	Equus capensis (22229) Equus helmei (22220 22224)
Miocene - Pleistocene	23.03 - 0.0117	South Africa	Equus helmei (22230)
Neogene - Pleistocene	23.03 - 0.0117	Argentina (Entre Rios)	Equus sp. (204259)
Hemingfordian	20.43 - 15.97	USA (Nevada)	Merychippus carrizoensis (18962)
Hemingfordian	20.43 - 15.97	USA (California)	Merychippus carrizoensis (19233 19367 19599) Merychippus tehachapiensis (19586)
Hemingfordian	20.43 - 15.97	USA (Colorado)	Calippus sp. (17908)
Late/Upper Hemingfordian	20.43 - 15.97	USA (New Mexico)	Protohippus group (19410)