Florissant mammal bed: Chadronian, Colorado

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia
? Copedelphys sp. Korth 1994
    = Herpetotherium huntii Cope 1873
Prothero and Sanchez 2004
recombined as Nanodelphys huntii
Mammalia - Perissodactyla - Rhinocerotidae
Rhinocerotidae indet. Gray 1821
Mammalia - Perissodactyla - Brontotheriidae
Brontotheriidae indet. (Marsh 1873)
Mammalia - Perissodactyla - Equidae
Mesohippus sp. Marsh 1875
Mammalia - Leptomerycidae
? Leptomeryx sp. Leidy 1853
Mammalia - Merycoidodontidae
Merycoidodon sp. Leidy 1848
see common names

Geography
Country:United States State/province:Colorado County:Teller
Coordinates: 38.9° North, 105.3° West (view map)
Paleocoordinates:40.4° North, 97.0° West
Basis of coordinate:based on political unit
Time
Period:Paleogene Epoch:Eocene
Stage:Priabonian 10 m.y. bin:Cenozoic 3
*Period:Tertiary *Local age/stage:Chadronian
Key time interval:Chadronian
Age range of interval:37.00000 - 33.90000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Florissant
Stratigraphic resolution:bed
Stratigraphy comments: said to be Chadronian
there are four 40Ar/39Ar dates on sanidine from three levels higher in the section, with overlapping errors: the first one up is from the "top of the caprock conglomerate" and is 34.03 +/- 0.09 Ma, and the weighted mean average of all four is 34.07 +/- 0.10 Ma; the entire formation is of reversed polarity, and the dates match it with Chron C13r (Prothero and Sanchez 2004)
"most of" the reported material comes from a single bed in the "lower mudstone unit" that is shown in a section diagram to be about 1 m thick and conglomeratic, and there is an unpublished micromammal fauna from somewhere in the same unit (Prothero and Sanchez 2004)
Lithology and environment
Primary lithology: conglomerate
Environment:fluvial indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:biostratigraphic analysis
Metadata
Database number:16968
Authorizer:J. Alroy Enterer:J. Alroy
Modifier:J. Alroy Research group:vertebrate
Created:1999-10-13 00:00:00 Last modified:2007-01-22 17:44:53
Access level:the public Released:1999-10-13 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:
1469. E. Evanoff and P. M. Detoledo. 1999. Fossil mammals and biting insects from the upper Eocene Florissant formation of Colorado. Journal of Vertebrate Paleontology 19(3):43A [J. Alroy/J. Alroy/J. Ju]

Secondary references:

19711 D. R. Prothero and F. Sanchez. 2004. Magnetic stratigraphy of the upper Eocene Florissant Formation, Teller County, Colorado. New Mexico Museum of Natural History and Science Bulletin 26:145-149 [J. Alroy/J. Alroy]