PBDB Collection

Crazy Johnson: Chadronian, South Dakota

List of taxa

Where & when

Geology

Taphonomy & methods

Metadata & references

Taxonomic list

Reptilia - Testudines

	Dermatemydidae indet. Baur 1888
	"Anosterine" marginal plates
	= Anosteirinae indet. Lydekker 1889	Hutchison 1996
Reptilia - Testudines - Kinosternoidea

	Xenochelys formosa Hay 1906
	described by Williams 1952
Reptilia - Testudines - Geoemydidae

	Graptemys cordifera Clark 1937
Reptilia - Testudines - Emydidae

	Trachemys antiqua Clark 1937
Reptilia

	Alligator cf. prenasalis (Loomis 1904)
Mammalia - Rodentia - Eomyidae

	Eomyidae indet. Winge 1887

	Adjidaumo sp. Hay 1899
Mammalia - Pantolestidae

	Cymaprimadon kenni n. sp. Clark 1968	Clark 1968
Mammalia - Proscalopidae

	Arctoryctes galbreathi Reed 1956
Mammalia - Carnivora - Amphicyonidae

	Daphoenocyon dodgei (Scott 1898)

	Daphoenus sp. Leidy 1853
	confirmed by Hunt 1998b
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 - Creodonta - Hyaenodontidae

	Hyaenodon cf. cruentus Leidy 1853
	= Hyaenodon cf. horridus Leidy 1853	Alroy 2002
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
	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 - Rhinocerotidae

	Caenopus mitis (Cope 1875)

	Trigonias osborni Lucas 1900
Mammalia - Perissodactyla - Hyracodontidae

	Hyracodon cf. priscidens Lambe 1905
Mammalia - Perissodactyla - Equidae

	Mesohippus latidens Douglass 1903
	(1 measurement)
	= Mesohippus bairdi Leidy 1850	Alroy 2002
	and "M. hypostylus"
Mammalia - Protoceratidae

	Poabromylus kayi Peterson 1932
	(6 measurements)
	= Pseudoprotoceras longinaris Cook 1934	Emry and Storer 1981
	replaces ID of Wilson 1974; FMNH collection
Mammalia - Agriochoeridae

	Agriochoeridae indet. Leidy 1869

	Agriochoerus cf. antiquus Leidy 1850
Mammalia - Hypertragulidae

	Hypertragulidae indet. Cope 1879
Mammalia - Camelidae

	Camelidae indet. Gray 1821
Mammalia - Anthracotheriidae

	Heptacodon sp. Marsh 1894

	Bothriodon americanus (Leidy 1856)
	= Aepinacodon cf. americanus Leidy 1856	Alroy 2002
	mentioned by Macdonald 1956b as "A. sp."
Mammalia - Tayassuidae

	Perchoerus minor Cook 1922	Prothero 2009
	FMNH PM20802
see common names

Geography

Country:	United States	State/province:	South Dakota	County:	Pennington and Shannon
Coordinates:	43.6° North, 102.5° West (view map)
Paleocoordinates:	49.1° North, 85.0° West (Wright 2013)
Basis of coordinate:	based on political unit

Time

Period:	Paleogene	Epoch:	Eocene
Stage:	Priabonian	10 m.y. bin:	Cenozoic 3
*Period:	Tertiary
Key time interval:	Chadronian
Age range of interval:	37 - 33.9 m.y. ago
* legacy (obsolete) database fields

Stratigraphy

Formation:	Chadron	Member:	Crazy Johnson
Local section:	BgBad	Local bed:	2
Local order:	bottom to top

Lithology and environment

Environment:

terrestrial indet.

Taphonomy

Modes of preservation:

body

Collection methods and comments

Reason for describing collection:

paleoecologic analysis

Metadata

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:	2025-02-22 15:12:02
Access level:	the public	Released:	1993-02-18 00:00:00
Creative Commons license:	CC0

Reference information

Primary reference:

1235.

ETE 10023

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]

Secondary references:

6294		J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Kouvari]
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]