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 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]
| 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 edit
Fish edit
Cartilaginous fish edit
| 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 edit
| Bony fish of the Demopolis Chalk Formation | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
E. petrosus[2] |
An enchodontid |
 | ||
|
P. gladius[2] |
||||
|
X. vetus[4] |
||||
Reptiles edit
Dinosaurs edit
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 |
 | ||||
Mosasaurs edit
| Mosasaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
M. conodon[2] |
 | |||
|
P. primaevus[5] |
||||
|
P. cf. rapax |
||||
Plesiosaurs edit
| Plesiosaurs of the Demopolis Chalk | ||||
|---|---|---|---|---|
| Genus | Species | Presence | Notes | Images |
|
Elasmosaurus sp.[2] |
An elasmosaurid |
 | ||
See also edit
References edit
- ^ a b c 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.
- ^ a b c d e f g h i j 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 2009-02-02.
- ^ a b c d e f 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.
- ^ 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. Retrieved 2009-02-02.