Myton Pocket (Eocene of the United States)

Also known as Protylopus Quarry

Where: Duchesne County, Utah (40.2° N, 109.9° W: paleocoordinates 43.0° N, 98.9° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: lower Myton Member (Uinta Formation), Uintan (46.2 - 40.4 Ma)

Environment/lithology: terrestrial; lithology not reported

Size class: macrofossils

Primary reference: J. L. Kay. 1957. The Eocene vertebrates of the Uinta Basin, Utah. Intermountain Association of Petroleum Geologists, Guidebook, 8th Annual Field Conference 110-114 [J. Alroy/J. Alroy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 16607: authorized by John Alroy, entered by John Alroy on 12.04.1997

Creative Commons license: CC BY (attribution)

Taxonomic list

• according to Burke 1934b, Myton Pocket was not discovered until 1912, so earlier Uinta C records cannot belong to it
Kay's list is for all of Uinta C; I have removed records not tied to Myton Pocket by revised list of Prothero 1996a or other sources
Black and Sutton also list "Leptotomus grangeri"
Myton Pocket is 7 mi. E of Myton, Duchesne Co. (often said to be 6 mi E or SE of Myton) and is close to the base of Uinta C
Protylopus Quarry is within Myton Pocket
"Uintatherium sp." of Kay is probably erroneous, see Wheeler 1961

"Hyrachyus sp." could be Triplopus sensu Radinsky 1967a and no specimens are discussed in the literature

"Mesamynodon medius" of Kay is of unclear status because no material of this species or its sometime synonym "Hyracodon primus" has ever been attributed to the Uinta Fm. sensu stricto

"Hylomeryx simplicidens" of Kay appears to be a nomen nudum

"Achaenodon sp." is listed by Kay, but no other publication suggests that this genus is present above Uinta B

"Simimeryx minutus" is listed by Kay, but no specimen other than the type from Red Narrows is discussed in the literature
 Anseriformes - Anatidae
Eonessa anaticula n. gen. n. sp.13
Eonessa anaticula n. gen. n. sp.13 Wetmore 1938 waterfowl
collected by John Clark in 1936
 Crocodylia - Alligatoridae
Procaimanoidea utahensis n. gen. n. sp.6
Procaimanoidea utahensis n. gen. n. sp.6 Gilmore 1946 crocodilian
 Primates - Omomyidae
Ourayia uintensis9 Osborn 1895 tarsier
Myton Pocket
Ourayia hopsoni12 Robinson 1968 tarsier
 Rodentia - Eutypomyidae
Janimus rhinophilus n. sp.2 Dawson 1966 rodent
Myton Pocket
 Rodentia - Ischyromyidae
Pseudotomus eugenei1 Burke 1935 rodent
referred specimen is from Myton Pocket, but type is from Myton Mbr. at "Head of west fork of Antelope Draw, beneath the rim of Deadman Bench, Uinta County": Burke 1935a; I cannot locate Antelope Draw, but Kay 1934 shows Deadman Bench as running most of the way between Ouray and Kennedy's Hole north of the White River, so this may be in Uinta C in the Wagonhound Canyon section
Paramys compressidens n. sp. Peterson 1919 rodent
from Myton Pocket: see Peterson 1919
Thisbemys medius1 Peterson 1919 rodent
from Myton Pocket according to Peterson 1919, but from "three miles west of Chipeta Wall" according to Wood 1962 (this locality is not discussed by any other author)
"Prosciurus robustus n. sp." = Mytonomys robustus10 Peterson 1919 rodent
from "Horizon C... six miles east of Myton"
 Rodentia - Cylindrodontidae
Pareumys milleri n. sp.10 Peterson 1919 rodent
Myton Pocket; said by Prothero 1996a to be from White River Pocket
 Lagomorpha - Leporidae
Mytonolagus petersoni n. sp. Burke 1934 rabbit
see Burke 1934b
 Perissodactyla - Brontotheriidae
Brontotheriidae indet.1 Marsh 1873 brontothere
genus listed at Myton Pocket by Prothero 1996a; genus invalid according to Mader 2000; also "Brontotherium curtum": status unclear as Mader 1989 restricts Megacerops to the Chadronian
 Perissodactyla -
"Isectolophus annectens n. sp." = Isectolophus annectens10, "Schizolophodon cuspidens n. gen. n. sp." = Isectolophus annectens10
"Isectolophus annectens n. sp." = Isectolophus annectens10 Scott and Osborn 1887 odd-toed ungulate
Myton Pocket; not clear why this is omitted by Kay, who may have been confused by the unclear provenance of the type; also includes his "Parisectolophus sp."
"Schizolophodon cuspidens n. gen. n. sp." = Isectolophus annectens10 Scott and Osborn 1887 odd-toed ungulate
 Perissodactyla - Amynodontidae
Amynodon advenus11 Marsh 1875 odd-toed ungulate
Myton Pocket; probably includes "A. intermedius" and "A. advenum?" of Wall 1982 from Uinta C
 Perissodactyla - Hyracodontidae
Epitriplopus uintensis1 Peterson 1919 odd-toed ungulate
from Myton Pocket (see Peterson 1919) and also "E. sp.": see Radinsky 1967a
Triplopus obliquidens1 Scott and Osborn 1887 odd-toed ungulate
also "Triplopus sp.": former from Myton Pocket, see Peterson 1919
 Perissodactyla - Rhinocerotidae
Uintaceras radinskyi n. sp.7 Holbrook and Lucas 1997 rhinoceros
Myton Pocket; "Forstercooperia sp." of Holbrook 1994
 Perissodactyla - Equidae
Epihippus gracilis Marsh 1871 horse
includes "E. parvus" of Prothero 1996a from Myton Pocket
 Tribosphenida - Micropternodontidae
Micropternodus sp.11 Matthew 1903 placental
 Tribosphenida -
Talpavus duplus n. sp.8 Krishtalka 1976 placental
 Ferae -
Tapocyon robustus1 Peterson 1919 placental
type is from Myton Pocket: see Peterson 1919
 Carnivora - Miacidae
Miocyon scotti1 Wortman and Matthew 1899 carnivoran
at Myton Pocket: Prothero 1996a
 Carnivora -
Procynodictis vulpiceps3 Wortman and Matthew 1899 carnivoran
Uinta C, confirmed as Myton Pocket by Prothero 1996a; includes type and referred specimen of "Miacis gracilis" of Clark 1939 from "7 miles east and south of Myton": see also Wang and Tedford 1994
 Ungulata - Homacodontidae
Hylomeryx quadricuspis10 Peterson 1919 even-toed ungulate
paratypes, from Myton Pocket
"Bunomeryx elegans" = Bunomeryx montanus Wortman 1898 even-toed ungulate
at Myton Pocket: Prothero 1996a
Pentacemylus progressus4 Peterson 1932 even-toed ungulate
Myton Pocket
Mytonomeryx scotti n. sp.4 Gazin 1955 even-toed ungulate
from Myton Pocket
Auxontodon pattersoni5 Gazin 1958 even-toed ungulate
"near entrance of Myton Pocket"
 Ungulata - Camelidae
Poebrodon kayi n. sp.4 Gazin 1955 camel
from Myton Pocket
 Ungulata - Oromerycidae
Protylopus annectens n. sp. Peterson 1919 even-toed ungulate
see Gazin 1955: Myton Pocket
Oromeryx plicatus11 Marsh 1894 even-toed ungulate
 Ungulata - Agriochoeridae
Agriochoeridae indet., Protoreodon petersoni n. sp.4, "Protoreodon pumilus" = Protoreodon pumilus, "Protoreodon medius n. sp." = Protoreodon pumilus10, "Agriochoerus matthewi" = Diplobunops matthewi10
Agriochoeridae indet. Leidy 1869 agriochoerid
Protoreodon petersoni n. sp.4 Gazin 1955 agriochoerid
Myton Pocket
"Protoreodon pumilus" = Protoreodon pumilus Marsh 1875 agriochoerid
see Gazin 1955: includes "Protagriochoerus annectens" from Myton Pocket, see Gazin 1955
"Protoreodon medius n. sp." = Protoreodon pumilus10 Marsh 1875 agriochoerid
Peterson 1919 very clearly lists type of "P. medius" from Myton Pocket, but no Uinta C material is indicated by Prothero 1996a
"Agriochoerus matthewi" = Diplobunops matthewi10 Peterson 1919 agriochoerid
Myton Pocket; see also Peterson 1931c, Black 1978
 Ungulata - Protoceratidae
Leptotragulus medius n. sp. Peterson 1919 protoceratid
at Myton Pocket, including 23 specimens from Protylopus Quarry, and type is from "Uinta C, 6 miles east of Myton," which appears to be the same locality: see Gazin 1955
Leptotragulus proavus Scott and Osborn 1887 protoceratid
at Myton Pocket: Prothero 1996a
Leptotragulus clarki Gazin 1955 protoceratid
type is from Protylopus Quarry: see Gazin 1955
Leptoreodon marshi11 Wortman 1898 protoceratid
 Acreodi -
"Pleurocyon magnus n. gen. n. sp." = Simidectes magnus10
"Pleurocyon magnus n. gen. n. sp." = Simidectes magnus10 Peterson 1919 mesonychian
6 mi SE of Myton, near base of Myton Mbr. horizon C, and also possibly from horizon B; "Pleurocyon magnum"
 Acreodi - Mesonychidae
Harpagolestes leotensis11 Peterson 1931 condylarth
Myton Pocket; presumably "Mesonyx uintensis" of Kay 1957; may include "Uinta C" record of West 1981
 Hyaenodonta -
Limnocyon potens11 Matthew 1909 eutherian
Proviverra longipes1 Peterson 1919 eutherian
type is from Myton Pocket: see Peterson 1919