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
GenusSpeciesPresenceNotesImages
Chimaeriformes indet.AlabamaIschyrhiza mira rostral spines Teeth of Scapanorhynchus texanus Squalicorax sp.
CretolamnaC. appendiculataAlabamaAn otodontid
IschyrhizaI. miraAlabamaA sclerorhynchid
ScapanorhynchusS. texanusAlabamaA mitsukurinid
SerratolamnaS. serrata?AlabamaA lamniform shark
SqualicoraxS. kaupiAlabamaAnacoracids
S. pristodontus
S. sp.

Bony fish

Bony fish of the Demopolis Chalk Formation
GenusSpeciesPresenceNotesImages
EnchodusE. feroxAlabamaEnchodontidsEnchodus petrosus Protosphyraena Stratodus
E. gladiolus
E. petrosus
ProtosphyraenaP. sp.AlabamaA pachycormiform
SaurodonS. sp.AlabamaAn ichthyodectiform
StratodusS. sp.AlabamaAn aulopiform
XiphactinusX. vetusAn ichthyodectid

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
GenusSpeciesPresenceNotesImages
AppalachiosaurusA. montgomeriensisGeographically present in Alabama.A tyrannosauroidAppalachiosaurus

Crocodylians

Crocodylians of the Demopolis Chalk Formation
GenusSpeciesPresenceNotesImages
BorealosuchusB. sp.AlabamaAn eusuchianBorealosuchus skull

Mosasaurs

Mosasaurs of the Demopolis Chalk
GenusSpeciesPresenceNotesImages
ClidastesC. propythonAlabamaA mosasaurineClidastes propython Plioplatecarpus
HalisaurusH. sp.AlabamaA halisaurine
MosasaurusM. conodonAlabamaA mosasaurine
M. cf. missouriensis
PlatecarpusP. cf. somenensisAlabama and MississippiA plioplatecarpine
PlioplatecarpusP. sp. nov.MississippiA plioplatecarpine
TylosaurusT. sp.Alabama and MississippiA tylosaurine

Turtles

Turtles of the Demopolis Chalk
GenusSpeciesPresenceNotesImages
AsmodochelysA. parhamiGeographically present in Alabama and Mississippi.A marine ctenochelyid turtleProtostega gigas
ChedighaiiC. barberiAlabamaA bothremydid
CtenochelysC. cf. tennuitestaAlabamaA ctenochelyid
PrionochelysP. matutina?AlabamaA ctenochelyid
ProtostegaP. gigasAlabamaA protostegid

See also