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Merycoidodontidae (oreodont)

Mammalia - Ungulata - Merycoidodontidae

Synonymy list
YearName and author
1869Oreodontidae Leidy
1873Oreodontidae Leidy p. 318
1884Oreodontidae Cope p. 503
1889Oreodontidae Cope p. 876
1891Oreodontidae Cope p. 21
1910Oreodontidae Gregory p. 466
1911Oreodontidae Jaekel p. 234
1912Merycoidodontidae Cook p. 45
1937Merycoidodontidae Thorpe p. 31
1940Merycoidodontidae Scott p. 648
1950Phenacocoelinae Schultz and Falkenbach p. 95
1954Desmatochoerinae Schultz and Falkenbach p. 153
1969Merycoidodontidae Ferrusquia-Villafranca
1969Merycoidodontidae Stevens et al. p. 26
1969Phenacocoelinae Stevens et al. p. 26
1996Merycoidodontidae Stevens and Stevens p. 510
1996Phenacocoelinae Stevens and Stevens p. 510
1997Oreodontidae McKenna and Bell p. 408
1998Merycoidodontidae Lander
2003Merycoidodontidae Parris and Grandstaff p. 63
2009Oreodontidae Morgan et al.
2011Oreodontidae Lander and Lindsay p. 221

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phylumChordataHaeckel 1847
subclassDipnotetrapodomorpha(Nelson 2006)
orderUngulata(Linnaeus 1766)

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.

M. S. Stevens and J. B. Stevens 1996Oreodonts are suiform, selenodont artiodactyls that differ from most Agriocho- eridae by lack of a divided P4para-metacone, usual absence of molar labial ribs, the posterior arm of the protoselene usually directed medially and deeply into the median valley between the protocone and hypocone, usual absence of protoconules, and a usually closed postorbital. The Merycoidodontidae usually lack diastema (except those to receive the caniform teeth), have a full dental series of 13/3, Cl/1, P4/4, and M3/3, an incisiform lower canine, caniform Pt, and molars with W-shaped ectolophs.
Oreodont crania primitively have rather steep premaxillae, usually short Subnasal L. and a strongly convex nasal profile, but the profile becomes progres- sively straighter or more concave, and the Subnasal L. increases in some genera as the nasal notch migrates posteriorly. One genus firmly coalesces the rostrum ventral to the nasal aperture which causes the external nares to migrate posteriorly , and three genera greatly shorten the length of the nasal bones. Oreodont skulls are usually mesocephalic but certain groups become more brachycephalic, and one group becomes quite dolichocephalic. The orbits are situated in the mid- cranial region, and are primitively located relatively low on the sides of the face. Facial vacuities are absent in primitive species but are characteristic of numerous derived genera. The zygoma are usually unspecialized but become massively upturned in several taxa. The nuchal crest is primitively narrow and protracted strongly posteriorly, but the crest becomes less protracted and considerably expanded laterally in some specialized forms and a sagittal table may develop. Some genera progressively either develop or reduce the depth of the preorbital fossae, and auditory bullae vary from small to notably enlarged. Oreodont lower jaws consistently have a greatly enlarged, rounded angular region that is not much expanded below the ventral border of the horizontal ramus.
No measurements are available
Composition: phosphaticsubp
Environment: terrestrialo
Locomotion: actively mobilec
Life habit: ground dwellingf
Diet: herbivoref
Created: 2005-08-31 14:37:21
Modified: 2005-08-31 16:37:21
Source: f = family, o = order, c = class, subp = subphylum
References: Nowak 1999, Lander 1998, Carroll 1988, Hendy et al. 2009

Age range: base of the Uintan to the top of the Tortonian or 46.20000 to 7.24600 Ma

Collections (892 total)

Oldest occurrences

Time interval Ma Country or state Original ID and collection number
Uintan46.2 - 40.4Mexico (Oaxaca) Merycoidodon sp. (166797)
Duchesnean40.4 - 37.2USA (Texas) Aclistomycter middletoni (16819 16820 16821 16849)
Chadronian37.2 - 33.9USA (Nebraska) Merycoidodon culbertsoni (16929 17018) Merycoidodon culbertsonii (16895 17037) Merycoidodon sp. (16917 16930 16940 17014) Miniochoerus gracilis, Merycoidodon culbertsoni, Otionohyus wardi (16918) Otionohyus vanderpooli (17035) Stenopsochoerus douglasensis (17040)
Chadronian37.2 - 33.9USA (Texas) Bathygenys reevesi, Limnenetes platyceps (16888) Bathygenys reevesi, Merycoidodon dunagani (17016) Bathygenys sp. (16934) Limnenetes platyceps (16890) Merycoidodon dunagani (16931) Merycoidodontidae indet. (16894) Prodesmatochoerus meekae (16889)
Chadronian37.2 - 33.9USA (Montana) Limnenetes platyceps, Limnenetes anceps (17028) Merycoidodon culbertsoni (17041) Merycoidodon sp. (16914 16915) Merycoidodontidae indet., Bathygenys alpha (16959 16988 17010) Merycoidodontidae indet., Bathygenys alpha, Oreonetes anceps, Limnenetes sp. (16990) Oreonetes anceps (16909)
Chadronian37.2 - 33.9Canada (Saskatchewan) Bathygenys sp., Merycoidodon macrorhinus (16919) Merycoidodon sp. (16979) Oreodontidae indet. (101961)
Chadronian37.2 - 33.9USA (Colorado) Genetochoerus periculorum, Merycoidodon gracilis, Merycoidodon culbertsoni (16977) Merycoidodon sp. (16968)
Chadronian37.2 - 33.9USA (South Dakota) Merycoidodon lewisi (17006) Merycoidodon sp., Miniochoerus forsythae (16885) Otionohyus wardi (16967)
Chadronian37.2 - 33.9Mexico (Chihuahua) Merycoidodon sp., Bathygenys alpha, Aclistomycter middletoni (17015)
Chadronian37.2 - 33.9USA (Wyoming) Bathygenys alpha, Merycoidodon culbertsoni, Merycoidodon gracilis (16920) Bathygenys alpha, Merycoidodon forsythae, Bathygenys alpha (16962) Bathygenys sp. (16966) Bathygenys sp., Merycoidodon forsythae (16965) Bathygenys sp., Merycoidodon lewisi (16960) Bathygenys sp., Merycoidodon sp. (16961) Megabathygenys goorisi (16987) Merycoidodon culbertsoni (16902 16908 16998) Merycoidodon culbertsoni, Stenopsochoerus chadronensis (17024) Merycoidodon forsythae (16952) Merycoidodon forsythae, Bathygenys alpha (16963) Merycoidodon forsythae, Megabathygenys goorisi, Bathygenys alpha (16964) Merycoidodon sp. (16903 16911) Merycoidodon sp., Bathygenys alpha (17045) Miniochoerus chadronensis, Merycoidodon culbertsoni, Otionohyus wardi (16942) Miniochoerus chadronensis, Parastenopsochoerus conversensis, Stenopsochoerus douglasensis, Merycoidodon culbertsoni (16943) Miniochoerus forsythae (16980) Otionohyus wardi (16974)

Youngest occurrences

Time interval Ma Country or state PBDB collection number
Clarendonian13.6 - 10.3USA (Nebraska) Ustatochoerus major (18028 18099 18135 18145 18156 18214 18218 18221 18227 18231 18300 18333 18425 18430 18458 18468 18496) Ustatochoerus medius (18077 18260) Ustatochoerus profectus (18042 18060 18095 18204 18251 18301 18362 18447) Ustatochoerus skinneri (18092 18315 18324 188779) Ustatochoerus sp. (18106 18108 18157 18176 18194 18217 18233 18294 18456)
Clarendonian13.6 - 10.3USA (Texas) Metoreodon sp. (207452) Ustatochoerus major, Ustatochoerus profectus (18096) Ustatochoerus medius, Metoreodon sp. (18623) Ustatochoerus profectus (18104 18244 18355) Ustatochoerus sp., Oreodontidae indet. (18645)
Clarendonian13.6 - 10.3USA (Kansas) Ustatochoerus sp. (18186 18219)
Early/Lower Clarendonian13.6 - 10.3USA (Nebraska) Ustatochoerus profectus (18134)
Late/Upper Clarendonian13.6 - 10.3USA (New Mexico) Merychyus major (157331)
Late/Upper Clarendonian13.6 - 10.3USA (Nebraska) Ustatochoerus major (18066)
Clarendonian - Hemphillian13.6 - 4.9USA (Wyoming) Ustatochoerus medius (18424)
Clarendonian - Hemphillian13.6 - 4.9USA (Nebraska) Merychyus major (18295) Ustatochoerus major (18180) Ustatochoerus profectus (18069)
Tortonian11.62 - 7.246USA (California) Ustatochoerus major (52210)
Hemphillian10.3 - 4.9USA (Nebraska) Ustatochoerus major (18033 18499)