Lakota Formation
| Lakota Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Sub-units | Chilson Member. Fuson Member |
| Underlies | Fall River Formation |
| Overlies | Morrison Formation |
| Thickness | 200 to 500 feet (60 to 150 m) |
| Lithology | |
| Primary | Sandstone |
| Other | Shale, Coal, Conglomerate |
| Location | |
| Region | North America |
| Country | United States |
| Type section | |
| Named for | Lakota Native American tribe |
| Named by | Darton |
| Year defined | 1899 |
The Lakota Formation is a sequence of rocks of early Cretaceous (Berriasian to Barremian) age from Western North America. Located in South Dakota, the name of the formation is derived from the Lakota Native American tribe.
There are two units of the Lakota Formation, the Chilson Member (upper Berriasian to Valanginian) and the underlying Fuson Member (upper Valanginian to early Barremian). A Berriasian-Valanginian age for the Chilson Member has been extrapolated by means of ostracods and charophytes.[1]
The Fuson Member takes its name from rock exposures in Fuson Canyon, a valley on the eastern side of the Black Hills.[2]
Vertebrate paleofauna
[edit | edit source]Dinosaurs
[edit | edit source]| Dinosaurs reported from the Lakota Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|
D. lakotaensis |
Chilson Member |
"Skull, mandible, [and] vertebrae."[4] |
||||
|
H. marshi |
Chilson Member |
"Partial postcranial skeleton [and] osteoderms."[5] |
An ankylosaur belonging to Polacanthidae |
|||
|
O. depressus |
Chilson Member |
Portions of both ilia, anterior part of the blade of one pubis, an incomplete sacrum, centrum of the last sacro-dorsal, 12 caudal vertebrae, 1 thoracic rib and many fragments |
An ankylopollexian iguanodont |
|||
| Indeterminate |
Chilson Member |
Left humerus and right metacarpal I |
A macronarian related to Camarasaurus |
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Mammals
[edit | edit source]| Mammals reported from the Lakota Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|
B. hydei[9] |
Chilson Member |
Right M2 |
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|
I. rougieri |
Chilson Member |
Right lower M1 |
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|
L. luoi |
Chilson Member |
Right upper molar (M5?) |
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|
P. angelli |
Chilson Member |
Right M1 |
A plagiaulacid multituberculate | |||
Turtles
[edit | edit source]| Turtles reported from the Lakota Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Lakotemys[10] | L. australodakotensis | Chilson Member | Two shells and a partial skull | A baenid paracryptodire | ||
Other vertebrate remains found within the Lakota Formation include a fish scale from the gar Lepisosteus and a crocodile tooth [11]
References
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- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ "Table 19.1," in Weishampel, et al. (2004). Page 416.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 366.
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
 | This article about a specific stratigraphic formation in South Dakota is a stub. You can help Wikipedia by expanding it. |
- Geologic formations of South Dakota
- Cretaceous geology of South Dakota
- Cretaceous Manitoba
- Cretaceous geology of Nebraska
- Berriasian Stage
- Valanginian Stage
- Hauterivian Stage
- Barremian Stage
- Lower Cretaceous Series of North America
- Sandstone formations of the United States
- Shale formations of the United States
- Coal formations
- Conglomerate formations of the United States
- Midwestern United States geologic formation stubs
- South Dakota geography stubs