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| Demopolis Chalk Stratigraphic range: Upper Cretaceous | |
|---|---|
| Type | Geological formation |
| Unit of | Selma Group |
| Sub-units | Bluffport Marl Member |
| Underlies | Ripley Formation |
| Overlies | Mooreville Chalk Formation |
| Lithology | |
| Primary | Chalk |
| Location | |
| Region | Alabama, Mississippi, Tennessee |
| Country | United States |
| Type section | |
| Named for | Demopolis, Alabama |
The Demopolis Chalk is a geological formation in North America, within the United States states of Alabama, Mississippi, and Tennessee . The chalk was formed by pelagic sediments deposited along the eastern edge of the Mississippi embayment during the middle Campanian stage of the Late Cretaceous.[1] It is a unit of the Selma Group and consists of the upper Bluffport Marl Member and a lower unnamed member.[2] Dinosaur and mosasaur remains are among the fossils that have been recovered from the Demopolis Chalk.[2][3]
| Cartilaginous fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
C. appendiculata[2] |
An Otodontid |
| ||
|
Scapanorhynchus sp.[2] |
||||
|
S. kaupi |
||||
|
S. pristodontus[2] |
||||
|
I. mira[2] |
||||
|
C. samhammeri |
||||
|
A. "kopingensis" |
||||
| Bony fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
E. petrosus[2] |
An enchodontid |
| ||
|
P. gladius[2] |
A pachycormid | |||
|
X. vetus[4] |
||||
Indeterminate hadrosaurid remains have been found in Tennessee .[3] Possible indeterminate tyrannosaurid remains have been found in Alabama.[3]
| Dinosaurs of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
Geographically present in Alabama.[3] |
A tyrannosauroid |
| ||
| Mosasaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
M. conodon[2] |
A mosasaurine |
| ||
|
P. primaevus[5] |
A plioplatecarpine | |||
|
P. cf. rapax |
A mosasaurine | |||
| Plesiosaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
Elasmosaurus sp.[2] |
An elasmosaurid |
| ||