PBDB Taxon

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Merycoidodontinae

Mammalia - Merycoidodontidae

Taxonomy

Merycoidodontinae was named by Hay (1902).

It was assigned to Agriochoeridae by Hay (1902); and to Merycoidodontidae by Schultz and Falkenbach (1968), Stevens and Stevens (1996) and Stevens and Stevens (2007).

Subtaxa

Eucrotaphus (syn. Pseudogenetochoerus), Merycoidodon (syn. Promesoreodon, Cotylops, Subdesmatochoerus, Prodesmatochoerus, Oreodon, Genetochoerus, Paramerycoidodon, Otionohyus, Blickohyus), Mesoreodon

Synonyms

Eucrotaphus was named by Leidy (1850) [nomen nudum]. Its type is Eucrotaphus jacksoni.

It was synonymized subjectively with Agriochoerus by Leidy (1873), Thorpe (1921), Thorpe (1921) and Wilson (1971); it was synonymized subjectively with Oreodon by Scott (1890); it was considered a nomen dubium by Thorpe (1924); it was considered a nomen dubium by Scott (1940); it was considered a nomen vanum by Schultz and Falkenbach (1968); it was considered a nomen dubium by Stevens and Stevens (1996).

It was assigned to Oreodontidae by Cope (1884); to Merycoidodontinae by Hay (1902); to Oreodontoidea by McKenna and Bell (1997); and to Merycoidodontidae by Leidy (1850), Thorpe (1937) and Lander (1998).
Eucrotaphus jacksoni was named by Leidy (1850) [genotype]. It is the type species of Eucrotaphus.

It was synonymized subjectively with Agriochoerus antiquus by Leidy (1857) and Leidy (1869); it was recombined as Oreodon jacksoni by Scott (1890); it was considered a nomen dubium by Thorpe (1924); it was considered a nomen vanum by Schultz and Falkenbach (1968); it was considered a nomen dubium by Stevens and Stevens (1996).
Pseudogenetochoerus was named by Schultz and Falkenbach (1968).

It was synonymized subjectively with Eucrotaphus by Lander (1998).

It was assigned to Merycoidodontinae by Schultz and Falkenbach (1968).

Synonymy list

Year	Name and author
1850	Eucrotaphus Leidy
1850	Eucrotaphus jacksoni Leidy p. 90
1853	Eucrotaphus jacksoni Leidy
1884	Eucrotaphus Cope p. 513
1884	Eucrotaphus jacksoni Cope p. 517
1890	Oreodon jacksoni Scott
1902	Merycoidodontinae Hay p. 665
1902	Eucrotaphus Hay p. 666
1902	Eucrotaphus jacksoni Hay p. 666
1906	Eucrotaphus jacksoni Douglass p. 566
1937	Eucrotaphus Thorpe p. 61
1937	Eucrotaphus jacksoni Thorpe p. 61 figs. PI. I, figs. 13-15
1968	Pseudogenetochoerus Schultz and Falkenbach
1968	Merycoidodontinae Schultz and Falkenbach p. 24
1968	Pseudogenetochoerus Schultz and Falkenbach p. 156 figs. figures 14-16, 19, 20, 22, 52
1996	Merycoidodontinae Stevens and Stevens p. 512
1997	Eucrotaphus McKenna and Bell p. 408
1998	Eucrotaphus Lander
1998	Eucrotaphus jacksoni Lander
2007	Merycoidodontinae Stevens and Stevens p. 160

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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
—	Theriamorpha	(Rowe 1993)
—	Theriiformes	()
—	Trechnotheria
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Boreoeutheria
—	Laurasiatheria
—	Scrotifera
—	Euungulata
—	Artiodactylamorpha
—	Artiodactyla	()
family	Merycoidodontidae
subfamily	Merycoidodontinae
subfamily	Merycoidodontinae

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.

Subfm. †Merycoidodontinae Hay 1902

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G. †Merycoidodon Leidy 1848

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Subg. †Merycoidodon (Anomerycoidodon) Schultz and Falkenbach 1968

†Merycoidodon (Anomerycoidodon) lambi Schultz and Falkenbach 1968

Subg. †Merycoidodon (Blickohyus) Schultz and Falkenbach 1968

Subg. †Merycoidodon (Merycoidodon) Stevens and Stevens 1996

Subg. †Merycoidodon (Otarohyus) Schultz and Falkenbach 1968

†Merycoidodon bullatus Leidy 1869

Invalid names: Eporeodon cedrensis Matthew 1901 [synonym], Eporeodon major cedrensis Matthew 1901 [synonym], Eporeodon socialis Marsh 1884 [synonym], Eucrotaphus dickinsonensis Douglass 1907 [synonym], Eucrotaphus helenae Douglass 1902 [synonym], Genetochoerus (Osbornohyus) geygani Schultz and Falkenbach 1968 [synonym], Genetochoerus (Osbornohyus) norbeckensis Schultz and Falkenbach 1968 [synonym], Merycoidodon (Anomerycoidodon) dani Schultz and Falkenbach 1968 [synonym], Merycoidodon (Blickohyus) galushai Schultz and Falkenbach 1968 [synonym], Paramerycoidodon (Barbourochoerus) bacai Schultz and Falkenbach 1968 [synonym]

†Merycoidodon culbertsonii Leidy 1848

†Merycoidodon culbertsonii browni Schultz and Falkenbach 1968

†Merycoidodon culbertsonii osborni Schultz and Falkenbach 1968

†Oreodon culbertsoni periculorum Cope 1884

Invalid names: Cotylops speciosa Leidy 1851 [synonym], Merycoidodon lewisi Clark and Beerbower 1967 [synonym], Merycoidodon periculorum Cope 1884 [synonym], Oreodon macrorhinus Douglass 1903 [synonym], Oreodon priscum Leidy 1851 [synonym], Oreodon robustum Douglass 1902 [synonym], Otionohyus vanderpooli Schultz and Falkenbach 1968 [synonym], Otionohyus wardi Schultz and Falkenbach 1968 [synonym], Paramerycoidodon georgei Schultz and Falkenbach 1968 [synonym], Prodesmatochoerus meekae Schultz and Falkenbach 1954 [synonym]

†Merycoidodon major Leidy 1853

Invalid names: Desmatochoerus (Paradesmatochoerus) anthonyi Schultz and Falkenbach 1968 [synonym], Genetochoerus (Osbornohyus) chamberlaini Schultz and Falkenbach 1968 [synonym], Merycoidodon (Blickohyus) lynchi Schultz and Falkenbach 1968 [synonym], Merycoidodon lambi Schultz and Falkenbach 1968 [synonym], Merycoidodon lynchi Schultz and Falkenbach 1968 [synonym], Oreodon hybridus Leidy 1869 [synonym], Otionohyus (Otarohyus) alexi Schultz and Falkenbach 1968 [synonym], Paramerycoidodon (Gregoryochoerus) wanlessi Schultz and Falkenbach 1968 [synonym], Promesoreodon scanloni Schultz and Falkenbach 1949 [synonym], Subdesmatochoerus shannonensis Schultz and Falkenbach 1954 [synonym]

†Merycoidodon minor Cope 1888

†Merycoidodon presidioensis Stevens and Stevens 1996

Invalid names: Blickohyus Schultz and Falkenbach 1968 [synonym], Cotylops Leidy 1851 [synonym], Genetochoerus Schultz and Falkenbach 1968 [synonym], Oreodon Leidy 1851 [synonym], Otionohyus Schultz and Falkenbach 1968 [synonym], Paramerycoidodon Schultz and Falkenbach 1968 [synonym], Prodesmatochoerus Schultz and Falkenbach 1954 [synonym], Promesoreodon Schultz and Falkenbach 1949 [synonym], Subdesmatochoerus Schultz and Falkenbach 1954 [synonym]

G. †Mesoreodon Scott 1893

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†Mesoreodon chelonyx Scott 1893

Invalid names: Eporeodon meagherensis Schultz and Falkenbach 1968 [synonym], Eucrotaphus montanus Douglass 1907 [synonym], Mesoreodon danai Koerner 1940 [synonym], Mesoreodon intermedius Scott 1893 [synonym], Mesoreodon laticeps Loomis 1924 [synonym]

†Mesoreodon floridensis MacFadden and Morgan 2003

†Mesoreodon minor Douglass 1903

Invalid names: Desmatochoerus (Paradesmatochoerus) grangeri Schultz and Falkenbach 1954 [synonym], Desmatochoerus (Paradesmatochoerus) monroecreekensis Schultz and Falkenbach 1954 [synonym], Desmatochoerus (Paradesmatochoerus) sanfordi Schultz and Falkenbach 1954 [synonym], Desmatochoerus (Paradesmatochoerus) wyomingensis Schultz and Falkenbach 1954 [synonym], Desmatochoerus macrosynaphus Riel 1964 [synonym], Eporeodon cheeki Schlaikjer 1934 [synonym], Mesoreodon scotti Schlaikjer 1934 [synonym], Pseudodesmatochoerus wascoensis Schultz and Falkenbach 1954 [synonym]

Invalid names: Eucrotaphus Leidy 1850 [nomen vanum]

Diagnosis

Reference	Diagnosis
C. B. Schultz and C. H. Falkenbach 1968	Skulls moderately small to medium in size; dolichocephalic to mesocephalic ; low to moderately high; supraoccipital wings with moderate lateral spread (not fan-shaped as in Miniochoerinae), extending posteriorly above and posterior to condyles ; exoccipital foramen round to oblong ; supraorbital foramina may be close together or distantly separated ( most examples with prominent anterior grooves); anterior nasal-maxilla contact in area above posterior border of CJ to anterior border of P1 ; orbits round to oblong ; lacrimal fossa deep to shallow; nasals with slight anterior retraction, posterior border with much variation (acute, obtuse, or truncated) ; zygomatic arch with inward notch posterior to orbits ; slight to prominent pit or depression on face above anterior premolars ; bulla small (minute) to well inflated, with variation in depth of hyoidal groove (prominent in early geologic forms, lost in latest forms) ; postglenoid process compressed anteroposteriorly with varying degrees of robustness and inward slope of external borders ; glenoid surface arched anteroposteriorly; palate projecting posteriorly to region of posterior border of M3 ; noticeable increase in depth of ramus anteroposteriorly; inferior border of ramus approximately straight to a point below and posterior to Ms, then with a noticeable downward curve; ascending ramus moderately high, wide anteroposteriorly, posterior border with prominent robust rim or
M. S. Stevens and J. B. Stevens 1996	Medium-sized oreodonts primitively with narrow, high, and arched muzzles, steep premaxillae, Subnasal L./Nasal L. ratios averag- ing from 53% to 47%, deep preorbital fossae, infraor- bital foramina above P 2 , and small auditory bullae each with a deep hyoidal groove. Later species have lower and broader muzzles, more inclined premaxillae, smaller preorbital fossae, infraorbital foramina above P4, broad frontals, and progressively more inflated auditory bullae which lose the hyoidal groove. Dentally, the Merycoidodontinae remained conserva- tive throughout their history, with unreduced premolars 50-48% of the pl_P4;pl_M3 ratio (rounded averages; Table 3), an APM3/TM3 ratio that is primitively 1.0 or slightly less but increases to 1.18 in the youngest species (averages; Table 5), and with persistently brachydont-submesodont dentitions where the APM3/Ht. M3 ratio averages 1.80 to 1.53 (Table 4). Over time, the TM3/Ht. M3 ratio progressively decreases from 1.80 to 1.36 (Table 6). The Merycoi- dodontinae differ from Miniochoerinae by progres- sively larger size, lack of thinned enamel on the premolar-molar middle crests and selenes, and by inflated auditory bullae in species younger than earlier Orellan; and differ by grade only from Eporeodontinae by a usually larger size (species younger than Orellan), an arched, instead of a concave nasal profile, and complete absence of facial vacuities.