Demopolis Chalk
Geological formation in the United States
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The Demopolis Chalk is a geological formation in North America, within the U.S. 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 age 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]
| 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 |
Vertebrate paleofauna
Fish
Cartilaginous fish
| Cartilaginous fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
Chimaeriformes indet.[4] |
   | |||
|
An otodontid | ||||
|
S. texanus[4] |
||||
|
S. serrata?[4] |
A lamniform shark | |||
|
S. kaupi[4] |
||||
|
S. sp.[4] | ||||
Bony fish
Reptiles
Dinosaurs
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 |
 | ||||
Crocodylians
| Crocodylians of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
B. sp.[4] |
An eusuchian |
 | ||
Mosasaurs
| Mosasaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
C. propython[4] |
  | |||
|
H. sp.[4] |
||||
|
M. cf. missouriensis[4] | ||||
|
P. cf. somenensis[4] |
||||
|
P. sp. nov.[7] |
Mississippi[6] | |||
|
T. sp.[4] |
||||
Turtles
| Turtles of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
A. parhami[8] |
Geographically present in Alabama and Mississippi.[8] |
A marine ctenochelyid turtle |
 | |
|
C. barberi[4] |
||||
|
C. cf. tennuitesta[4] |
||||
|
P. matutina?[4] |
||||
|
P. gigas[4] |
||||
