Also known as North of Big Hole River; South side of McCarty's Mountain; McCartney Mountain; MV 5813; MV 5908; MV 6201; MV 6202
Where: Madison County, Montana (45.5° N, 112.6° W)
• Paleocoordinates: 52.2° N, 95.7° W (Wright 2013)
• coordinate stated in text
When: Chadron Formation (White River Group), Chadronian (37.2 - 33.9 Ma)
• "Titanotherium beds, Lower White River formation" - Gilmore 1928.
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•Lower White River/Titanotherium beds = Chadron Fm (Hoganson et al., 1998)
Environment/lithology: wet floodplain; fine-grained, quartzose, gray tuff
•The water table must have been very near and in places above the surface providing conditions too moist for large trees, but suitable for shrubs and other low vegetation. Frequent and widespread flooding of the floodplain by sluggish streams took place. The flooding could be the result of rainfall or could be caused by faulting and/or plugging of the watercourses by lava and ash from the widespread volcanic activity in the area as postulated by Pardee (1950), Freeman, Ruppel, and Klepper (1958), and Mann (1954). The lower and upper beds in the measured section were deposited at the basin margin as indicated by the very large boulders of andesite brought into the sediment by swift-flowing small tributary streams. The lack of channels in the middle beds could indicate that the margin of the basin had shifted and the area of deposition was no longer at the edge of the basin. Renewed faulting might explain the re-occurrence of tributary channels in the upper beds. However, the lock of any unconformity within the sequence argues against this interpretation.
Size classes: macrofossils, mesofossils
Collected by Earl Douglass
Primary reference: E. Douglass. 1905. The Tertiary of Montana. Memoirs of the Carnegie Museum 2(5):203-221 [J. Alroy/J. Alroy/J. Marcot]more details
Purpose of describing collection: general faunal/floral analysis
PaleoDB collection 16990: authorized by John Alroy, entered by John Alroy on 15.05.2002, edited by Jonathan Marcot, Terri Cleary, Evangelos Vlachos and Greg Liggett
Creative Commons license: CC BY (attribution)
Taxonomic list
"Ischyromys typus" is NOT present, this material is "Titanotheriomys": Wood 1980
Mammalia | |
"Ictops montanus" = Leptictis montanus, "Leptictis montanus" = Leptictis montanus, "Ictops magnus" = Leptictis
"Ictops montanus" = Leptictis montanus Douglass 1905 eutherian
"Leptictis montanus" = Leptictis montanus Douglass 1905 eutherian
"Ictops magnus" = Leptictis eutherian | |
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Apternodus baladontus n. sp.1
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Hyaenodon sp. Laizer and Parieu 1838 creodont | |
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"Xenotherium unicum n. sp." = Epoicotherium unicum
"Xenotherium unicum n. sp." = Epoicotherium unicum Douglass 1905 placental | |
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Montanatylopus matthewi n. sp.6
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"Agriochoerus minimus" = Protoreodon minimus
"Agriochoerus minimus" = Protoreodon minimus Douglass 1902 agriochoerid probably includes Douglass' "Agriochoerus sp."
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Ischyromys douglassi n. sp.2
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Reptilia | |
Testudo peragrans n. sp.5
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"Helodermoides tuberculatus" = Helodermoides tuberculatus13, "Glyptosaurus montanus n. sp." = Helodermoides tuberculatus4
"Helodermoides tuberculatus" = Helodermoides tuberculatus13 Douglass 1903 squamates CM 9975, nearly complete skull and gular region, body osteoderms, vertebrae, and ribs
"Glyptosaurus montanus n. sp." = Helodermoides tuberculatus4 Douglass 1903 squamates CM 1050 (holotype), nearly complete skull and lower jaws, partial limb and phalangeal bones.
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