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Orohippus pumilus

Mammalia - Perissodactyla - Equidae

Taxonomy
Lophiodon pumilus was named by Marsh (1871) [genotype; not the same as "Lophiodon pumilus"; also said to be 1871, confusing this with Lophiodon pumilus]. It is a 3D body fossil. Its type locality is Grizzly Buttes, which is in a Bridgerian terrestrial horizon in the Bridger Formation of Wyoming. It is the type species of Helohippus.

It was recombined as Hyrachyus pumilus by Leidy (1872); it was synonymized subjectively with Orohippus procyoninus by Cope (1873) and Cope (1875); it was recombined as Helohippus pumilus by Marsh (1892), Matthew (1899) and Hay (1902); it was recombined as Pachynolophus pumilus by Roger (1896); it was recombined as Helaletes pumilus by Wood (1934); it was recombined as Orohippus pumilus by Scott et al. (1871), Marsh (1872), Marsh (1874), Matthew (1899), Carrano (1902), Granger (1908), Stirton (1940), Kitts (1957), Gazin (1976), MacFadden (1998) and Froehlich (2002).

Synonyms
Synonymy list
YearName and author
1871Helotherium procyoninum Cope p. 466
1871Lophiodon pumilus Marsh p. 38
1871Lophiotherium ballardi Marsh p. 39
1871Orohippus pumilus Scott and et al.
1872Hyrachyus pumilus Leidy
1872Orohippus pumilus Marsh
1872Orotherium ballardi Marsh
1873Oligotomus cinctus Cope p. 2
1874Orohippus pumilus Marsh p. 249
1875Orohippus procyoninus Cope p. 22
1877Hyracotherium procyoninum Cope
1883Hyracotherium osbornianum Cope p. 647 figs. Plate XXIV; fig. 23
1884Lambdotherium procyoninum Cope
1884Pliolophus cinctus Cope
1892Helohippus pumilus Marsh p. 353
1896Lambdotherium procyoninum Roger
1896Pachynolophus ballardi Roger
1896Pachynolophus cinctus Roger
1896Pachynolophus pumilus Roger
1896Orohippus cinctus Wortman
1898Orohippus osbornianus Trouessart
1899Helohippus pumilus Matthew
1899Hyracotherium osbornianum Matthew
1899Hyracotherium procyoninum Matthew
1899Orohippus cinctus Matthew
1899Orohippus pumilus Matthew
1902Orohippus pumilus Carrano
1902Helohippus pumilus Hay p. 611
1902Orohippus ballardi Hay p. 611
1902Orohippus cinctus Hay p. 611
1902Orohippus osbornianus Hay p. 611
1902Orohippus procyoninus Hay p. 612
1908Hyracotherium osbornianum Granger
1908Orohippus atavus Granger
1908Orohippus ballardi Granger
1908Orohippus pumilus Granger
1908Orohippus typicus Granger
1909Orohippus procyoninus Matthew
1930Orohippus ballardi Hay
1930Orohippus cinctus Hay
1930Orohippus osbornianus Hay
1930Orohippus typicus Hay
1934Helaletes pumilus Wood
1940Orohippus ballardi Stirton
1940Orohippus osbornianus Stirton
1940Orohippus pumilus Stirton
1940Orohippus typicus Stirton
1957Orohippus pumilus Kitts p. 10
1976Orohippus pumilus Gazin
1998Orohippus pumilus MacFadden p. 542
2002Orohippus pumilus Froehlich p. 151

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Nephrozoa
Deuterostomia
phylumChordataHaeckel 1847
subphylumVertebrata
superclassGnathostomata
Osteichthyes()
Sarcopterygii
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
Tetrapoda()
Reptiliomorpha
Anthracosauria
Batrachosauria()
Cotylosauria()
Amniota
Synapsida()
Therapsida()
RankNameAuthor
infraorderCynodontia()
Epicynodontia
infraorderEucynodontia
Probainognathia
Mammaliamorpha
Mammaliaformes
classMammalia
subclassTribosphenida()
infraclassEutheria()
Placentalia
orderPerissodactyla()
suborderLophodontomorpha
infraorderEuperissodactyla
Hippomorpha
superfamilyEquoidea
familyEquidae
genusOrohippus
speciespumilus()

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.

Diagnosis
ReferenceDiagnosis
D. B. Kitts 1957Diastema between pI and p2. P2 with lobe-like posterointernal shelf. P3 with acute (50-55º) antero-external angle and ob- tuse (125-130°) antero-internal angle. Mesostyle very weak or absent on P3 and P4. Anterior and posterior borders of P4 parallel and proto- cone distinctly more medial than hypocone. Mesostyle moderate on molars. P4 may be pointed anteriorly. Heel of M3 narrow and sharply constricted anteriorly.
Measurements
No measurements are available
Composition: phosphaticsubp
Environment: terrestrialsubc
Locomotion: actively mobilec
Life habit: ground dwellingf
Diet: browserf
Created: 2005-06-08 10:11:09
Modified: 2005-08-31 16:55:50
Source: f = family, subc = subclass, c = class, subp = subphylum
References: Nowak 1991, Carroll 1988, Hendy et al. 2009, Ji et al. 2002

Age range: Bridgerian or 50.30000 to 46.20000 Ma

Collections (32 total)


Time interval Ma Country or state Original ID and collection number
Bridgerian50.3 - 46.2USA (Wyoming) Lophiodon pumilus (16281) Orohippus atavus (16205) Orohippus osbornianus (16136) Orohippus pumilus (16089 16094 16105 16107 16108 16114 16116 16219 16227 type locality: 16228 16232 16262 16263 16269 16291 16300 16302 16303 16306 16309 16315 16321 16330 16336 16339 16353 16355 16441 16504)