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Merychyinae

Mammalia - Merycoidodontidae

Synonymy list
YearName and author
1945Merychyinae Simpson p. 149
1947Merychyinae Schultz and Falkenbach p. 168
1996Merychyinae Stevens and Stevens p. 510
2003Merychyinae Parris and Grandstaff p. 63
2007Merychyinae Stevens and Stevens p. 165
2023Merychyinae Stevens et al. p. 31

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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
RankNameAuthor
—Mammaliaformes
classMammalia
—Theriamorpha(Rowe 1993)
—Theriiformes()
—Trechnotheria
—Cladotheria
—Zatheria
subclassTribosphenida()
subclassTheria
—Eutheria()
—Placentalia
—Boreoeutheria
—Laurasiatheria
—Scrotifera
—Euungulata
—Artiodactylamorpha
—Artiodactyla()
familyMerycoidodontidae
subfamilyMerychyinae
subfamilyMerychyinae

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. †Merychyinae Simpson 1945
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G. †Merychyus Leidy 1858
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Subg. †Merychyus (Metoreodon) Matthew and Cook 1909
†Merychyus arenarum Cope 1884
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Invalid names: Merychyus arenarum idahoensis Schultz and Falkenbach 1947 [invalid subgroup], Merychyus arenarum leptorhynchus Cope 1884 [invalid subgroup], Merychyus euryops Cope 1899 [synonym]
†Merychyus calaminthus Jahns 1940
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Invalid names: Merychyus crabilli Schultz and Falkenbach 1947 [synonym], Merychyus crabilli ziaensis Schultz and Falkenbach 1968 [synonym], Merychyus jahnsi Whistler 1967 [synonym]
†Merychyus elegans Leidy 1858
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Invalid names: Merychyus paniensis Loomis 1924 [synonym]
†Merychyus minimus Peterson 1907
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Invalid names: Merychyus delicatus Loomis 1924 [synonym]
†Merychyus relictus Matthew and Cook 1909
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Invalid names: Merychyus (Metoreodon) relictus taylori Schultz and Falkenbach 1947 [invalid subgroup]
†Merychyus verrucomalus Stevens 1970
Invalid names: Merychyus (Metoreodon) relictus fletcheri Schultz and Falkenbach 1947 [invalid subgroup], Metoreodon Matthew and Cook 1909 [synonym]
G. †Oreodontoides Thorpe 1921
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†Oreodontoides curtus Loomis 1924
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Invalid names: Desmatochoerus anthyonyi Schultz and Falkenbach 1968 [synonym]
G. †Paramerychyus Schultz and Falkenbach 1947
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†Paramerychyus harrisonensis Peterson 1907
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Invalid names: Merychyus siouxensis Loomis 1924 [synonym]
†Paramerychyus relictus Loomis 1924
Diagnosis
ReferenceDiagnosis
C. B. Schultz and C. H. Falkenbach 1947Oreodonts of small to medium size; skulls mesocephalic; occipital region showing much variation with the supraoccipital wings in- corporated into a fan-shaped occipital; orbits large for size of skull; tendency for slight retraction of the nasals (anterior tip above C/); tympanic bulla well inflated and large, with a round to somewhat flattened inferior surface; teeth moderately large, brachyodont to subhypsodont (all the teeth in Merychyinae are in reality brachyodont, and the terms subhypsodont and brachyodont used in this paper are strictly comparative terms), premolars with simple to complicated patterns, the latter type found in the later Miocene species; PLP3 with anterior intermediate crest and Pa with posterior intermediate crest.
M. S. Stevens et al. 2023Small size (the smallest known Mioceneoreodonts), with shortened faces, slightly retracted nasals, wideinflated braincase with low sagittal crests, delicate zygomaticarches, arched frontal profile, small facial vacuities, a broadshallow lacrimal fossa anterior to the orbit, which forms a flat-bottomed depression. They have greatly inflated auditory bullaewith a “swollen” external auditory meatus, which completelyfills the space between the postglenoid and paroccipitalprocesses. The bulla is an inflated, sac-like structure with aslightly convex or flattened ventral surface that has a slightanteromedial slope. They have a relatively broad and fan-shapedoccipital region. The dentition is characterized by a longer molarrow that becomes quite hypsodont in later forms, and reducedpremolars, small caniniform teeth, and relatively long, delicate,slender limbs compared to most other larger Miocene oreodonts.
Measurements
No measurements are available
Composition: phosphaticsubp
Environment: terrestrialo
Locomotion: actively mobilec
Life habit: ground dwellingf
Diet: herbivoref
Reproduction: viviparoussubc
Created: 2005-08-31 14:37:21
Modified: 2005-08-31 16:37:21
Source: f = family, o = order, subc = subclass, c = class, subp = subphylum
References: Hendy et al. 2009, Nowak 1999, Carroll 1988, Lillegraven 1979, Lander 1998

Age range: base of the early Early Arikareean to the top of the Clarendonian or 29.50000 to 9.40000 Ma

Collections (188 total)


Time interval Ma Country or state Original ID and collection number
Bartonian - Rupelian41.3 - 28.1Mexico (Oaxaca) Oreodontoides sp. (166797)
Geringian30.8 - 26.3USA (Oregon) Oreodontoides oregonensis (17537)
Arikareean29.5 - 18.5USA (Oregon) Merychyus arenarum (188966 188967 188968) Merychyus arenarum, Merychyus calaminthus (188965) Oreodontoides oregonensis (93080)
Arikareean29.5 - 18.5USA (Texas) Merychyus calaminthus (178063)
Arikareean29.5 - 18.5USA (North Dakota) Merychyus sp. (17795)
Arikareean29.5 - 18.5USA (Wyoming) Merychyus arenarum (18883) Oreodontoides oregonensis (17703) Oreodontoides sp. (17490)
Arikareean29.5 - 18.5USA (South Dakota) Merychyus curtus (17498)
Arikareean29.5 - 18.5USA (California) Merychyus calaminthus (17851) Merychyus calaminthus, Merychyus jahnsi (17852)
early Early Arikareean - late Early Arikareean29.5 - 18.5USA (Wyoming) Merychyus harrisonensis (17491)
early Late Arikareean29.5 - 18.5USA (Arizona) Merychyus calaminthus (157243 157244)
late Late Arikareean29.5 - 18.5USA (Oregon) Merychyus calaminthus, Merychyus arenarum (18013)
late Late Arikareean29.5 - 18.5USA (California) Merychyus elegans (167849) Merychyus sp. (167826 167827)
late Late Arikareean29.5 - 18.5USA (Wyoming) Merychyus arenarum (18010)
Chattian28.1 - 23.03USA (Oregon) Oreodontoides oregonensis (17603 93079)
Monroecreekian26.3 - 24.8USA (South Dakota) Merychyus siouxensis (17723) Oreodontoides curtus (17564)
Monroecreekian - Harrisonian26.3 - 18.5USA (Oregon) Oreodontoides oregonensis (17528)
Harrisonian24.8 - 18.5USA (Texas) Merychyus sp. (17770 17772) Phenacocoelus leptoscelos (17767)
Harrisonian24.8 - 18.5USA (Montana) Merychyus siouxensis (17861)
Harrisonian24.8 - 18.5USA (Wyoming) Merychyus arenarum, Merychyus minimus (17780 17788 17793 17824 17835 17839 17847 17850) Merychyus crabilli, Merychyus harrisonensis (17853) Merychyus crabilli, Merychyus siouxensis (17801 17811) Merychyus crabilli, Merychyus siouxensis, Paramerychyus harrisonensis (17794) Merychyus minimus (17777 17817 17833 17838) Merychyus siouxensis (17798) Merychyus sp. (17796)
Harrisonian24.8 - 18.5USA (Nebraska) Merychyus crabilli (17806 17856) Merychyus elegans (17799) Merychyus minimus (17809) Merychyus siouxensis (17704 17733 17741 17843 28043) Merychyus sp. (17819 17863) Merychyus verrucomalus (17738)
Harrisonian24.8 - 18.5USA (South Dakota) Eporeodon relictus (17743) Merychyus delicatus (17748) Merychyus minimus (17745 17753 17754 17755 17830 17831) Merychyus sp. (17747) Oreodontoides curtus (17445)
Harrisonian24.8 - 18.5USA (California) Merychyus calaminthus (17760)
Harrisonian - Hemingfordian24.8 - 15.97USA (Montana) Merychyus sp. (18811)
Early/Lower Miocene23.03 - 15.97USA (California) Merychyus calaminthus (17765)
Miocene23.03 - 5.333USA (Colorado) Merychyus arenarum (18813)
Miocene23.03 - 5.333USA (New Mexico) Merychyus crabilli (19130)
Miocene23.03 - 5.333USA (South Dakota) Metoreodon sp. (18064) Ustatochoerus sp. (18080 18379)
Miocene23.03 - 5.333USA (Nebraska) Ustatochoerus sp. (18276)
Miocene23.03 - 5.333USA (California) Merychyinae indet. (19425) Merychyus calaminthus (19433)
Miocene23.03 - 5.333USA (Nevada) Merychyus elegans (18981)
Miocene23.03 - 5.333USA (Texas) Merychyus sp. (18693)
Miocene23.03 - 5.333Mexico (Aguascalientes) Merychyus elegans (18756)
Miocene23.03 - 5.333USA (Idaho) Merychyus arenarum (18980)
Miocene23.03 - 5.333USA (Louisiana) Merychyus sp. (163859)
Miocene23.03 - 5.333USA (Montana) Merychyus arenarum (18945) Merychyus sp. (19062)
Early/Lower Hemingfordian20.43 - 15.97USA (California) Merychyus elegans (167840 167841) Merychyus sp., Merychyus minimus (19194)
Early/Lower Hemingfordian20.43 - 15.97USA (Wyoming) Merychyus elegans (19046) Merychyus sp. (167862)
Early/Lower Hemingfordian20.43 - 15.97Mexico (Oaxaca) Merychyus minimus (18744)
Early/Lower Hemingfordian20.43 - 15.97USA (Oregon) Merychyus arenarum (17925 17966)
Early/Lower Hemingfordian20.43 - 15.97USA (Nebraska) Merychyus arenarum (17881) Merychyus elegans (17898 17926 17927 17930 17931 17934 17937 17939 17941 17942 17943 17944 17945 17989 18005 18021) Merychyus minimus (17924) Merychyus sp. (17892) Merychyus verrucomalus (17879 17962)
Early/Lower Hemingfordian20.43 - 15.97USA (New Mexico) Merychyus crabilli (19275)
Hemingfordian20.43 - 15.97USA (South Dakota) Merychyus arenarum (17912 72052)
Hemingfordian20.43 - 15.97Canada (Saskatchewan) Merychyus sp. (18003)
Hemingfordian20.43 - 15.97USA (Colorado) Merychyus elegans (17965)
Hemingfordian20.43 - 15.97USA (Wyoming) Merychyus arenarum (18948)
Hemingfordian20.43 - 15.97USA (Nebraska) Merychyus elegans (17867 17982) Merychyus minimus (17866) Merychyus relictus (17902 17917 17920 17952 17961 17979 17987 18000 18001) Merychyus sp. (17991)
Hemingfordian20.43 - 15.97USA (Nevada) Merychyus sp. (18962)
Late/Upper Hemingfordian20.43 - 15.97USA (New Mexico) Merychyus sp. (19410)
Hemingfordian - Barstovian20.43 - 12.5USA (California) Merychyus relictus (19478)
Barstovian16.3 - 12.5USA (California) Merychyus relictus (19153) Merychyus sp. (19137)
Barstovian16.3 - 12.5USA (Louisiana) Merychyus sp. (18621)
Barstovian16.3 - 12.5USA (Oregon) Merychyus sp. (19092)
Barstovian16.3 - 12.5USA (Idaho) Merychyus sp. (19013)
Barstovian16.3 - 12.5USA (South Dakota) Ustatochoerus sp. (18117)
Barstovian16.3 - 12.5USA (Nebraska) Metoreodon sp. (18123) Ustatochoerus sp. (18206 18412)
Early/Lower Barstovian16.3 - 12.5USA (New Mexico) Merychyus sp. (19547)
Early/Lower Barstovian16.3 - 12.5USA (Nebraska) Merychyus relictus (17903 17905 17911 17919 17955 17972 17976 17992 18004 18011 18019 18020)
Barstovian - Clarendonian16.3 - 9.4USA (Nebraska) Merychyus elegans (190543) Metoreodon profectus (230906) Ustatochoerus sp. (18235)
Clarendonian12.5 - 9.4USA (Oregon) Ustatochoerus sp. (18820 18822 18823)
Clarendonian12.5 - 9.4USA (South Dakota) Ustatochoerus sp. (18344)
Clarendonian12.5 - 9.4USA (Oklahoma) Ustatochoerus sp. (18130 18463)
Clarendonian12.5 - 9.4USA (Kansas) Ustatochoerus sp. (18186 18219)
Clarendonian12.5 - 9.4USA (Texas) Metoreodon sp. (207452) Ustatochoerus sp. (18149 18645)
Clarendonian12.5 - 9.4USA (Nevada) Ustatochoerus sp. (18835)
Clarendonian12.5 - 9.4USA (Nebraska) Ustatochoerus sp. (18106 18108 18157 18176 18194 18217 18233 18294 18456)
Late/Upper Miocene11.608 - 5.333USA (Wyoming) Ustatochoerus sp. (19044)