Basic info Taxonomic history Classification Included Taxa
Morphology Ecology and taphonomy External Literature Search Age range and collections

Merychyus

Mammalia - Merycoidodontidae

Synonymy list
YearName and author
1858Merychyus Leidy
1884Merychyus Cope p. 535
1890Merychyus Scott and Osborn p. 72
1902Merychyus Hay p. 669
1913Merychyus Scott p. 361
1937Merychyus Thorpe p. 216
1947Merychyus Schultz and Falkenbach p. 171 figs. SF:igures 1-7, 13,14,15-17
1998Merychyus Lander
2003Merychyus Parris and Grandstaff p. 63
2007Merychyus Stevens and Stevens p. 164
2009Merychyus Morgan et al.
2011Merychyus Lander and Lindsay p. 221
2023Merychyus Stevens et al. p. 37

Is something missing? Join the Paleobiology Database and enter the data

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
genusMerychyus

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.

G. †Merychyus Leidy 1858
show all | hide all
Subg. †Merychyus (Metoreodon) Matthew and Cook 1909
†Merychyus arenarum Cope 1884
hide
Invalid names: Merychyus arenarum leptorhynchus Cope 1884 [invalid subgroup], Merychyus euryops Cope 1899 [synonym]
†Merychyus calaminthus Jahns 1940
hide
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
hide
Invalid names: Merychyus paniensis Loomis 1924 [synonym]
†Merychyus minimus Peterson 1907
hide
Invalid names: Merychyus delicatus Loomis 1924 [synonym]
†Merychyus relictus Matthew and Cook 1909
hide
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], Merychyus arenarum idahoensis Schultz and Falkenbach 1947 [invalid subgroup], Metoreodon Matthew and Cook 1909 [synonym]
Diagnosis
ReferenceDiagnosis
C. B. Schultz and C. H. Falkenbach 1947
SKULL: Small, basal length ranging from 123 mm. to 178 mm.; mesocephalic; supra- occipital wings fan-shaped, widely spread, and incorporated in the occipital flare, but the flare not so pronounced as in the genus
Ustatochoerus; exoccipital pits roundish in outline but not so large as in Ustatochoerus; ~ase of paroccipital process not completely mcorporated in the fan-shaped region as in
Ustatochoerus or Merychyus (Metoreodon) (see fig. 14); sagittal crest prominent but not high; brain case inflated; zygomatic arch light to medium light; lacrimal fossa prom- inent in Harrison forms and shallow in later species; prelacrimal vacuity present; infra- orbital foramen either above posterior portion of pa or above P 4 ; nasals slightly retracted, extending posterior to the anterior of the orbits; premaxillae fused for a short distance; paroccipital process moderately long and heavy for size of skull; postglenoid process wide transversely, narrow anteroposteriorly, and long vertically; occipital condyles me- dium in size, but varying greatly in dimen- sions; bullae2 with various degrees of flatten- ing.
MANDIBLE: Small; moderately deep for size of skull; inferior border nearly straight with a slight downward curve just posterior
,to Ma; condyle of moderate size; symphysis prominent, posterior point below region of PrP,.
DENTITIONA:dvancedbrachyodonttosub- hypsodont; If and I~ approximately equal in size, with I~ larger; superior canines vary in size from small to large; P1 may be small or large.
LIMBS:Light to moderately heavy.
M. S. Stevens et al. 2023Medium-large sized merychyines with progressively more molarized premolars and more hypsodont cheek teeth in successive species. Fan-shaped occipital crests develop in the later species.
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: Lander 1998, Carroll 1988, Hendy et al. 2009, Lillegraven 1979, Nowak 1999

Age range: base of the Early/Lower Hemingfordian to the top of the Clarendonian or 20.43000 to 9.40000 Ma

Collections (166 total)


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