| 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 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. It is a unit of the Selma Group and consists of the upper Bluffport Marl Member and a lower unnamed member. Dinosaur and mosasaur remains are among the fossils that have been recovered from the Demopolis Chalk.
Vertebrate paleofauna
Fish
Cartilaginous fish
| Cartilaginous fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
Chimaeriformes indet. |
   | |||
|
C. appendiculata |
An otodontid | |||
|
I. mira |
||||
|
S. texanus |
||||
|
S. serrata? |
A lamniform shark | |||
|
S. kaupi |
||||
|
S. pristodontus | ||||
|
S. sp. | ||||
Bony fish
| Bony fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
E. ferox |
   | |||
|
E. gladiolus | ||||
|
E. petrosus | ||||
|
P. sp. |
||||
|
S. sp. |
||||
|
S. sp. |
An aulopiform | |||
|
X. vetus |
||||
Reptiles
Dinosaurs
Indeterminate hadrosaurid remains have been found in Tennessee. Possible indeterminate tyrannosaurid remains have been found in Alabama.
| Dinosaurs of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
A. montgomeriensis |
Geographically present in Alabama. |
 | ||
Crocodylians
| Crocodylians of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
B. sp. |
An eusuchian |
 | ||
Mosasaurs
| Mosasaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
C. propython |
  | |||
|
H. sp. |
||||
|
M. conodon |
||||
|
M. cf. missouriensis | ||||
|
P. cf. somenensis |
||||
|
P. primaevus |
||||
|
P. rapax |
||||
|
P. cf. solvayi | ||||
|
T. sp. |
||||
Turtles
| Turtles of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
A. parhami |
Geographically present in Alabama and Mississippi. |
A marine ctenochelyid turtle |
 | |
|
C. barberi |
||||
|
C. cf. tennuitesta |
||||
|
P. matutina? |
||||
|
P. gigas |
||||
See also
References
- ^ Carr, T.D.; Williamson, T.E.; Schwimmer, D.R. (2005). "A new genus and species of tyrannosauroid from the Late Cretaceous (middle Campanian) Demopolis Formation of Alabama". Journal of Vertebrate Paleontology. 25 (1): 119–143. doi:10.1671/0272-4634(2005)025[0119:ANGASO]2.0.CO;2. S2CID 86243316.
- ^ Kiernan, Caitlin R. (2002). "Stratigraphic distribution and habitat segregation of mosasaurs in the Upper Cretaceous of western and central Alabama, with an historical review of Alabama mosasaur discoveries". Journal of Vertebrate Paleontology. 22 (1): 91–103. doi:10.1671/0272-4634(2002)022[0091:SDAHSO]2.0.CO;2. Retrieved 2024-06-12.
- ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. ISBN 0-520-24209-2.
- ^ Kejiri, T.; Ebersole, J.A.; Blewitt, H.L.; Ebersole, S.M. (2013). "An Overview of Late Cretaceous Vertebrates from Alabama". Bulletin of the Alabama Museum of Natural History. 31 (1): 46–71.
- Schwimmer, D. R.; Stewart, J. D.; Williams, G. Dent (1997). "Xiphactinus vetus and the Distribution of Xiphactinus Species in the Eastern United States". Journal of Vertebrate Paleontology. 17 (3): 610–615. doi:10.1080/02724634.1997.10011007.
- Everhart, Mike (2008-04-18). "The Platecarpus Collection: A virtual collection of Platecarpus specimens from Kansas and elsewhere". Oceans of Kansas Paleontology. Archived from the original on 2024-03-17. Retrieved 2024-06-12.
- ^ Andrew D. Gentry; Jun A. Ebersole; Caitlin R. Kiernan (2019). "Asmodochelys parhami, a new fossil marine turtle from the Campanian Demopolis Chalk and the stratigraphic congruence of competing marine turtle phylogenies". Royal Society Open Science. 6 (12): Article ID 191950. Bibcode:2019RSOS....691950G. doi:10.1098/rsos.191950. PMC 6936288. PMID 31903219.