Middle Park (Upper): Middle Miocene, Colorado

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Perissodactyla - Equidae
Parahippus sp. (Leidy 1858)
    = Equidae indet. Gray 1821
Izett 1975
Hypohippus sp. (Leidy 1858)
Izett 1975
original and current combination Anchitherium (Hypohippus)
Merychippus sp. Leidy 1856
    = Equinae indet. Steinmann and Döderlein 1890
Alroy 2002
Mammalia - Perissodactyla - Chalicotheriidae
Macrotherium sp. Lartet 1837
    = Chalicotheriidae indet. Gill 1872
Alroy 2002
Mammalia - Perissodactyla - Rhinocerotidae
Aphelops cf. profectus (Matthew 1899)
    = Peraceras cf. profectum Matthew 1899
Alroy 2002
"? A. megalodus or ? A. profectus" of Izett and Lewis 1963 from USGS D520
Mammalia - Merycoidodontidae
Brachycrus laticeps (Douglass 1900)
    = Brachycrus sp. Matthew 1901
Kelly and Lander 1988
invalid subgroup of Merycochoerus
"cf. B. siouxense or B. wilsoni"
Mammalia - Camelidae
Camelidae indet. Gray 1821
two forms, said to be "Alticamelus-like" and "Oxydactylus-like"
Protolabis angustidens (Cope 1874)
    = Protolabis heterodontus Cope 1874
Alroy 2002
Mammalia - Antilocapridae
Paracosoryx sp. (Frick 1937)
original and current combination Cosoryx (Paracosoryx)
Mammalia - Rodentia - Mylagaulidae
Mylagaulidae indet. Cope 1881
"Mylagaulus laevis or M. vetus"
see common names

Geography
Country:United States State/province:Colorado County:Grand
Coordinates: 40.2° North, 106.1° West (view map)
Paleocoordinates:40.8° North, 103.2° West
Basis of coordinate:based on political unit
Geographic resolution:small collection
Time
Period:Neogene Epoch:Miocene
10 m.y. bin:Cenozoic 5
*Period:Tertiary
Key time interval:Middle Miocene
Age range of interval:15.98000 - 11.63000 m.y. ago
Age estimate:12.8 ± 3.0 Ma (other)
* legacy (obsolete) database fields
Stratigraphy
Formation:Troublesome Member:upper
Local section:Middl Local bed:3
Local order:bottom to top
Stratigraphic resolution:group of beds
Stratigraphy comments: upper part of "orange-gray siltstone and sandstone unit"
JA: Hemingfordian to Barstovian based on AEO results
dated at 12.8 +/- 2.0 Ma FT zircon, 10.9 +/- 1.4 Ma FT glass: Izett 1975
additional dates of 13.3 +/- 0.6 Ma, 13.5 +/- 0.4 Ma (FT on zircon: avg = 13.4 Ma): Kelly and Lander 1988
Lithology and environment
Primary lithology: not reported
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:general faunal/floral analysis
Museum repositories:USGS
Metadata
Also known as:USGS D520
Database number:18979
Authorizer:J. Alroy Enterer:J. Alroy
Modifier:B. Allen Research group:vertebrate
Created:1993-09-27 00:00:00 Last modified:2023-07-29 04:42:19
Access level:the public Released:1993-09-27 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:
2225. G. E. Lewis. 1969. United States Geological Survey Professional Paper 650-B [J. Alroy/J. Alroy]

Secondary references:

6294 J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Kouvari]
2000 G. A. Izett. 1975. Late Cenozoic sedimentation and deformation in northern Colorado and adjoining areas. Geological Society of America Memoir 144:179-209 [J. Alroy/J. Alroy]
2070 T. S. Kelly and E. B. Lander. 1988. Biostratigraphy and Correlation of Hemingfordian and Barstovian Land Mammal Assemblages, Caliente Formation, Cuyama Valley Area, California. In W. J. M. Bazeley (ed.), Tertiary Tectonics and Sedimentation in the Cuyama Basin, San Luis Obispo, Santa Barbara, and Ventura Counties, California 1-19 [J. Alroy/J. Alroy/J. Marcot]