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Dinohippus pachyops

Mammalia - Perissodactyla - Equidae

Taxonomy
Protohippus pachyops was named by Cope (1893) [also said to be 1893]. It is a 3D body fossil.

It was recombined as Merychippus pachyops by Hay (1902); it was recombined as Anchippus pachyops by Ameghino (1904) and Trouessart (1905); it was recombined as Pliohippus pachyops by Matthew and Stirton (1930), McGrew and Meade (1938), Stirton and Chamberlain (1939), Webb (1969) and MacFadden (1984); it was recombined as Pliohippus (Pliohippus) pachyops by Stirton (1940); it was synonymized subjectively with Pliohippus pernix by Hulbert (1989) and Kelly (1995); it was synonymized subjectively with Hypohippus affinis by Forsten (1991); it was synonymized subjectively with Pliohippus fossulatus by Kelly (1998); it was considered a nomen dubium by Macdonald (1992); it was recombined as Dinohippus pachyops by MacFadden (1998).

Synonymy list
YearName and author
1893Protohippus pachyops Cope p. 24
1902Merychippus pachyops Hay
1904Anchippus pachyops Ameghino
1905Anchippus pachyops Trouessart
1907Protohippus pachyops Gidley p. 912
1918Protohippus pachyops Osborn p. 138 figs. Plates 23.1,1a,2, 24.2,2a. T ext Fig. 110
1930Pliohippus pachyops Matthew and Stirton
1938Pliohippus pachyops McGrew and Meade p. 201
1939Pliohippus pachyops Stirton and Chamberlain
1940Pliohippus (Pliohippus) pachyops Stirton p. 192
1969Pliohippus pachyops Webb
1984Pliohippus pachyops MacFadden
1998Dinohippus pachyops MacFadden p. 551

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Nephrozoa
Deuterostomia
phylumChordataHaeckel 1847
OlfactoresJefferies 1991
subphylumVertebrata
Gnathostomata()
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
subfamilyEquinaeSteinmann and Döderlein 1890
tribeEquini
genusDinohippus
speciespachyops()

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
H. F. Osborn 1918 (Cope) (1) Malar-maxillary ridge obtusely rounded; (2) no preorbital fossa, an oval maxillo-nasal fossa which is strongly pronounced; (3) infraorbital foramen issuing above middle of m1; (4) the deciduous premolar crowns with protocone section greater longitudinally than transversely, junction with protoconule complete; (5) two enamel folds in prefossette; (6) superior molars with elongate crowns, well curved transversely; (7) inferior with para- conid and hypostylid well developed.
Gidley observes (1907, p. 913) that (1) Cope's conclusions were based on a misconception of the age of the specimen; (2) that the characters of the type are in general those of Protohippus but differ in several important details from any previously described species; (3) that the young skull referred to this species by Cope agrees closely with that of[?] Protohippus affinis.