Crazy Johnson: Chadronian, South Dakota

List of taxa
Where & when
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Testudines - Kinosternoidea
Xenochelys formosa Hay 1906
described by Williams 1952
Reptilia - Testudines
Dermatemydidae indet. Baur 1888
"Anosterine" marginal plates
    = Anosteirinae indet. Lydekker 1889
Hutchison 1996
Reptilia - Testudines - Geoemydidae
Graptemys cordifera Clark 1937
synonym of Echmatemys lativertebralis
Reptilia - Testudines - Emydidae
Trachemys antiqua Clark 1937
Reptilia - Alligatoridae
Alligator cf. prenasalis (Loomis 1904)
Mammalia - Pantolestidae
Cymaprimadon kenni n. sp. Clark 1968
Clark 1968
Mammalia - Rodentia - Eomyidae
Eomyidae indet. Winge 1887
Adjidaumo sp. Hay 1899
Mammalia - Perissodactyla - Brontotheriidae
Brontotherium hypoceras (Cope 1874)
    = Brontotheriidae indet. Marsh 1873
Osborn 1929
referred: middle beds, "level probably correct"
Menodus giganteus (Pomel 1849)
    = Megacerops sp. Leidy 1870
Mader 1989
in part
Menodus giganteus (Pomel 1849)
    = Menops sp. Marsh 1887
Mader 1989
synonym of Megacerops
in part; may include type of "Allops crassicornis" of Osborn 1902, from "middle beds" or possibly "upper beds" and of uncertain geographic provenance: Osborn 1929
Mammalia - Perissodactyla - Hyracodontidae
Hyracodon cf. priscidens Lambe 1905
Mammalia - Perissodactyla - Rhinocerotidae
Caenopus mitis (Cope 1875)
recombined as Subhyracodon mitis
Trigonias osborni Lucas 1900
Mammalia - Perissodactyla - Equidae
Mesohippus latidens Douglass 1903
(1 measurement)
    = Mesohippus bairdi Leidy 1850
Alroy 2002
and "M. hypostylus"
Mammalia - Proscalopidae
Arctoryctes galbreathi Reed 1956
recombined as Oligoscalops galbreathi
Mammalia - Carnivora - Amphicyonidae
Daphoenus sp. Leidy 1853
confirmed by Hunt 1998b
Daphoenocyon dodgei (Scott 1898)
recombined as Brachyrhynchocyon dodgei
Mammalia - Carnivora - Nimravidae
Eusmilus sp. Gervais 1876
Hoplophoneus oharrai Jepsen 1926
    = Hoplophoneus mentalis Sinclair 1921
Alroy 2002
this includes the type, see Bryant 1996
Mammalia - Ungulata - Tayassuidae
Perchoerus minor Cook 1922
Prothero 2009
FMNH PM20802
Mammalia - Ungulata - Camelidae
Camelidae indet. Gray 1821
Mammalia - Ungulata - Agriochoeridae
Agriochoeridae indet. Leidy 1869
Agriochoerus cf. antiquus Leidy 1850
Mammalia - Ungulata - Anthracotheriidae
Bothriodon americanus (Leidy 1856)
    = Aepinacodon cf. americanus Leidy 1856
Alroy 2002
mentioned by Macdonald 1956b as "A. sp."
Heptacodon sp. Marsh 1894
Mammalia - Ungulata - Protoceratidae
Poabromylus kayi Peterson 1932
(6 measurements)
    = Pseudoprotoceras longinaris Cook 1934
Emry and Storer 1981
replaces ID of Wilson 1974; FMNH collection
Mammalia - Ungulata - Hypertragulidae
Hypertragulidae indet. Cope 1879
Mammalia - Hyaenodonta - Hyaenodontidae
Hyaenodon cf. cruentus Leidy 1853
    = Hyaenodon cf. horridus Leidy 1853
Alroy 2002
see common names

Country:United States State/province:South Dakota County:Pennington and Shannon
Coordinates: 43.6° North, 102.5° West (view map)
Paleocoordinates:44.9° North, 93.6° West
Basis of coordinate:based on political unit
Period:Paleogene Epoch:Eocene
Stage:Priabonian 10 m.y. bin:Cenozoic 3
Key time interval:Chadronian
Age range of interval:37.20000 - 33.90000 m.y. ago
* legacy (obsolete) database fields
Formation:Chadron Member:Crazy Johnson
Local section:BgBad Local bed:2
Local order:bottom to top
Lithology and environment
Environment:terrestrial indet.
Modes of preservation:body
Collection methods and comments
Reason for describing collection:paleoecologic analysis
Database number:16938
Authorizer:J. Alroy, J. Marcot Enterer:J. Alroy, J. Marcot
Modifier:J. Alroy Research group:vertebrate
Created:1993-02-18 00:00:00 Last modified:2006-09-13 00:29:51
Access level:the public Released:1993-02-18 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:

1235.ETE 10023J. 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]

Secondary references:

6294 J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Uhen]
1234 J. Clark. 1968. Cymaprimadontidae A New Family of Insectivores. Fieldiana 16(8) [J. Alroy/J. Alroy/J. Ju]
1454 R. J. Emry and J. E. Storer. 1981. The Hornless Protoceratid Pseudoprotoceras (Tylopoda: Artiodactyla) in the Early Oligocene of Saskatchewan and Wyoming. Journal of Vertebrate Paleontology 1(1):101-110 [J. Alroy/J. Alroy/M. Uhen]
34290 J. H. Hutchison. 1996. Testudines. In D. R. Prothero and R. J. Emry (eds.), The Terrestrial Eocene-Oligocene Transition in North America 337-353 [J. Alroy/J. Alroy]
2395 B. J. Mader. 1989. The Brontotheriidae: A Systematic Revision and Preliminary Phylogeny of North American Genera. In D. R. Prothero and R. M. Schoch (eds.), The Evolution of Perissodactyls [J. Alroy/J. Alroy/M. Uhen]
2708 H. F. Osborn. 1929. New Eurasiatic and American proboscideans. American Museum Novitates 393:1-22 [J. Alroy/J. Alroy/M. Carrano]
57282 D. R. Prothero. 2009. The Early Evolution of the North American Peccaries (Artiodactyla: Tayassuidae). Papers on Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne (Museum of Northern Arizona Bulletin 65) 509-541 [J. Marcot/J. Marcot]
2847 C. A. Reed and W. D. Turnbull. 1965. The Mammalian Genera Arctoryctes and Cryptoryctes From the Oligocene and Miocene of North America. Fieldiana 15(2) [J. Alroy/J. Alroy/J. Ju]