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Orohippus agilis

Mammalia - Perissodactyla - Equidae

Taxonomy
Orohippus agilis was named by Marsh (1873). Its type specimen is YPM 1268, a partial skeleton (fragmentary skull, forelimb, and vertebrae), and it is a 3D body fossil. Its type locality is Henry's Fork, which is in an Eocene terrestrial horizon in the Bridger Formation of Wyoming.

It was recombined as Hyracotherium agile by Cope (1877); it was recombined as Epihippus agilis by Osborn (1890).

Synonymy list
YearName and author
1873Orohippus agilis Marsh p. 407
1874Orohippus agilis Marsh p. 249
1875Orohippus agilis Cope p. 22
1877Hyracotherium agile Cope
1890Epihippus agilis Osborn
1892Orohippus agilis Marsh
1899Orohippus agilis Matthew
1902Orohippus agilis Hay p. 611
1908Orohippus agilis Granger p. 228
1940Orohippus agilis Stirton
1957Orohippus agilis Kitts p. 28
1998Orohippus agilis MacFadden p. 543

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RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Deuterostomia
phylumChordataHaeckel 1874
subphylumVertebrata
superclassGnathostomata
Osteichthyes()
subclassSarcopterygii()
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
Tetrapoda
Reptiliomorpha
Anthracosauria
subclassAmphibiosauriaKuhn 1967
Cotylosauria()
Amniota
subclassSynapsida
Therapsida()
infraorderCynodontia()
Mammaliamorpha
Mammaliaformes
RankNameAuthor
classMammalia
Theriamorpha(Rowe 1993)
Theriiformes()
Trechnotheria
Cladotheria
Zatheria
subclassTribosphenida()
subclassTheria
Eutheria()
Placentalia
Boreoeutheria
Laurasiatheria
Scrotifera
Euungulata
Panperissodactyla
superorderPerissodactylamorpha
orderPerissodactyla()
superfamilyEquoidea
familyEquidae
genusOrohippus
speciesagilis

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.

Orohippus agilis Marsh 1873
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Diagnosis
ReferenceDiagnosis
D. B. Kitts 1957No diastema between P1 and P2. P2 triangular, with small internal cusp. P4 fully molariform but with lateral border parallel to edge of palate. P3 like P4 but narrower internally than externally. Paraconule and metaconule of molars les prominent than in other species. Mesoloph strong. Ectoloph rises to points of external cusps. Ectoloph V about 90 degrees. P4 and lower molars with anterior cusps much closer together than posterior cusps. P4, M1, and M2 wider posteriorly than anteriorly. P4 widest tooth of lower series. Heel of m3 short and relatively broad.
Measurements
No measurements are available
Composition: phosphaticsubp
Environment: terrestrialsubc
Locomotion: actively mobilec
Life habit: ground dwellingf
Diet: browserf
Reproduction: viviparoussubc
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, Lillegraven 1979, Carroll 1988, Hendy et al. 2009, Ji et al. 2002

Age range: Middle Eocene or 48.60000 to 37.20000 Ma

Collections: one only


Time interval Ma Country or state Original ID and collection number
Middle Eocene48.6 - 37.2USA (Wyoming) Orohippus agilis (type locality: 81455)