Crazy Johnson (Eocene of the United States)

Where: Pennington and Shannon County, South Dakota (43.6° N, 102.5° W: paleocoordinates 44.9° N, 93.6° W)

• coordinate based on political unit

When: Crazy Johnson Member (Chadron Formation), Chadronian (37.2 - 33.9 Ma)

Environment/lithology: terrestrial

Primary reference: J. Clark and J. R. Beerbower. 1967. Geology, paleoecology, and paleoclimatology of the Chadron Formation. Fieldiana 5(5):21-74 [J. Alroy/J. Alroy/J. Alroy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 16938: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Testudines - Kinosternoidea
Xenochelys formosa Hay 1906 mud turtle
described by Williams 1952
 Testudines - Carettochelyidae
Anosteirinae indet.4 Lydekker 1889 turtle
"Anosterine" marginal plates
 Testudines - Pangeoemydidae
"Graptemys cordifera" = Echmatemys lativertebralis
"Graptemys cordifera" = Echmatemys lativertebralis Cope 1877 turtle
 Testudines - Panemydidae
Trachemys antiqua Clark 1937 slider
 Crocodylia - Alligatoridae
Alligator cf. prenasalis Loomis 1904 alligator
Mammalia
 Cimolesta - Pantolestidae
Cymaprimadon kenni n. sp.2 Clark 1968 eutherian
 Rodentia - Eomyidae
Eomyidae indet. Winge 1887 rodent
Adjidaumo sp. Hay 1899 rodent
 Perissodactyla - Brontotheriidae
Brontotheriidae indet.6, "Megacerops sp." = Megacerops5, "Menops sp." = Megacerops5
Brontotheriidae indet.6 Marsh 1873 brontothere
"Megacerops sp." = Megacerops5 Leidy 1870 brontothere
"Menops sp." = Megacerops5 Leidy 1870 brontothere
 Perissodactyla - Hyracodontidae
Hyracodon cf. priscidens Lambe 1905 odd-toed ungulate
 Perissodactyla - Rhinocerotidae
"Caenopus mitis" = Subhyracodon mitis Cope 1875 rhinoceros
Trigonias osborni Lucas 1900 rhinoceros
 Perissodactyla - Equidae
Mesohippus bairdi1 Leidy 1850 anchitheriine horse
 Tribosphenida - Proscalopidae
"Arctoryctes galbreathi" = Oligoscalops galbreathi
"Arctoryctes galbreathi" = Oligoscalops galbreathi Reed 1956 placental
 Carnivora - Amphicyonidae
Daphoenus sp., "Daphoenocyon dodgei" = Brachyrhynchocyon dodgei
Daphoenus sp. Leidy 1853 bear-dog
confirmed by Hunt 1998b
"Daphoenocyon dodgei" = Brachyrhynchocyon dodgei Scott 1898 bear-dog
 Carnivora - Nimravidae
Eusmilus sp. Gervais 1876 false sabre-tooth
Hoplophoneus mentalis1 Sinclair 1921 false sabre-tooth
 Ungulata - Tayassuidae
Perchoerus minor7 Cook 1922 peccary
FMNH PM20802
 Ungulata - Camelidae
Camelidae indet. Gray 1821 camel
 Ungulata - Agriochoeridae
Agriochoeridae indet. Leidy 1869 agriochoerid
Agriochoerus cf. antiquus Leidy 1850 agriochoerid
 Ungulata - Anthracotheriidae
Aepinacodon cf. americanus1 Leidy 1856 anthracothere
Heptacodon sp. Marsh 1894 anthracothere
 Ungulata - Protoceratidae
Pseudoprotoceras longinaris3 Cook 1934 protoceratid
 Ungulata - Hypertragulidae
Hypertragulidae indet. Cope 1879 ruminant
 Hyaenodonta - Hyaenodontidae
Hyaenodon cf. horridus1 Leidy 1853 eutherian