Mooreville Chalk

The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of the Late Cretaceous.^[1] The chalk was formed by pelagic sediments deposited along the eastern edge of the Mississippi embayment. It is a unit of the Selma Group and consists of the upper Arcola Limestone Member and an unnamed lower member.^[2] Dinosaur, mosasaur, and primitive bird remains are among the fossils that have been recovered from the Mooreville Chalk Formation.^[1][2][3]

Mooreville Chalk
Stratigraphic range: Upper Cretaceous
Type	Geological formation
Unit of	Selma Group
Sub-units	Arcola Limestone Member
Underlies	Demopolis Chalk Formation
Overlies	Eutaw Formation
Lithology
Primary	Chalk
Location
Region	Alabama, Mississippi
Country	United States

Fish

Cartilaginous fish

Cartilaginous fish of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Cretolamna	C. appendiculata[3]				A lamniform	Cretoxyrhina mantelli Squalicorax sp.
Cretoxyrhina	C. mantelli[3]				A lamniform
Edaphodon	E. barberi[4]				Chimaeriforms
	E. mirificus[4]
Ischyodus	I. williamsae[4]				A chimaeriform
Odontaspis	O. cuspidata				A lamniform
Propenser	P. hewletti[4]				Lamniformes
Ptychodus	P. mammillaris[4]				?Neoselachian incertae sedis
	P. mortoni[3]
	P. polygyrus[4]
Pseudocorax	P. affinis[4]				Lamniformes
	P. laevis[3]
Serratolamna	S. serrata[3]				A lamniform
Scapanorhynchus	S. rhaphiodon[4]				Lamniformes
	S. texanus[3]
Squalicorax	S. falcatus[4]				Lamniformes
	S. kaupi[3]

Bony fish

Bony fish of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Albula	A. dunklei[4]				An albuliform	Enchodus petrosus Saurodon leanus Xiphactinus audax
Bananogmius	B. crieleyi[4]				A tselfatiiform
Cimolichthys	C. nepaholica[4]				An aulopiform
Enchodus	E. petrosus[4][3]				An aulopiform
	E. saevus[4]
Hoplopteryx	Hoplopteryx sp.[4]				A trachichthyiform
Ichthyodectes	I. ctenodon[4]				An ichthyodectiform
Moorevillia	M. hardi[4]				A tselfatiiform
Pachyrhizodus	P. caninus[4]				A crossognathiform
Protosphyraena	P. gladius[3]				A pachycormid
Saurodon	S. leanus[4]				An ichthyodectiform
Stratodus	S. apicalis[4]				An aulopiform
Xiphactinus	X. audax[4]				An ichthyodectiform

Reptiles

Dinosaurs

Indeterminate hadrosaurid, nodosaurid, dinosaur egg, and ornithomimosaur fossils are known from Mooreville Chalk outcrops in Alabama.^[1] The nodosaurid remains most likely belong to a new taxon.^[5]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Dinosaurs reported from the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Angelinornis	A. antecessor				A. antecessor was originally described as Plegadornis antecessor, but the generic name Plegadornis was preoccupied, so the genus Angelinornis was erected to contain the species. It was later demonstrated that Angelinornis was a junior synonym of Ichthyornis, although the new combination I. antecessor was held to be valid for a while following the sinking of Angelinornis into Ichthyornis. Later the species would later be considered a junior synonym of the Ichthyornis type species, I. dispar.[1]	Eotrachodon Ichthyornis dispar Saurornitholestes
Eotrachodon[6]	E. orientalis	Alabama.			A hadrosaurid known from a nearly complete skeleton and nearly complete skull.
Halimornis[1][2]	H. thompsoni[1][2]	Alabama.[1]		"Vertebrae and limb elements."[7]	An enantiornithine
Ichthyornis[1][2]	I. antecessor				The species I. antecessor was made the type species of the genus Angelinornis in 1962. Later, I. antecessor and Angelinornis were shown to be junior synonyms of the Ichthyornis type species, I. dispar[1]
	I. dispar[1][2]	Alabama.[1]			An ichthyornithine.
Lophorhothon[1][3]	L. atopus[1][3]	Alabama.[1]			A primitive species of hadrosaurid known from only a few skull fragments.[1]
Saurornitholestes[5]	S. sp.				A dromaeosaurid.
Plegadornis	P. antecessor				The name Plegadornis antecessor was applied to a fossil believed to represent a new bird species, but the generic name Plegadornis was preoccupied, so the genus Angelinornis was erected to contain the "new" species. It was later demonstrated that Angelinornis was a junior synonym of Ichthyornis, although the new combination I. antecessor was held to be valid for a while following the sinking of Angelinornis into Ichthtyornis. Later the species would later be considered a junior synonym of the Ichthyornis type species, I. dispar.[1]

Mosasaurs

Mosasaurs of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Clidastes	C. liodontus[4]				Mosasaurines	Clidastes propython Eonatator sternbergii Globidens alabamaensis Platecarpus tympaniticus Selmasaurus russelli Tylosaurus proriger
	C. "moorevillensis"[3]
	C. propython[4][3]
Ectenosaurus	E. shannoni[8]				A plioplatecarpine
Eonatator	E. sternbergi (sic)[3][9]				A halisaurine E. sternbergii was formerly classified as Halisaurus sternbergii[10]
	E. zangerli[11]
Globidens	G. alabamaensis[3]				A mosasaurine
Mosasaurus	M. missouriensis[3]				A mosasaurine
Platecarpus	P. tympaniticus[3]				A plioplatecarpine
Prognathodon	P. rapax[4]				A mosasaurine
Selmasaurus	S. russelli[3]				A plioplatecarpine
Tylosaurus	T. proriger[4]				A tylosaurine

Plesiosaurs

Very rare elasmosaurs are present in this formation.^[3]

Plesiosaurs of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Trinacromerum	Trinacromerum sp.[3]				Polycotylids	Trinacromerum sp.

Pterosaurs

Pterosaurs of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Pteranodon	Pteranodon sp.[3]				Pteranodontids.	Pteranodon sp.

Turtles

Turtles of the Mooreville Chalk Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Bothremys	B. barberi[3]				A pelomedusid.	Protostega gigas
Corsochelys	C. haliniches				A dermochelyid.
Protostega	P. gigas[3]				A protostegid.
Toxochelys	T. moorevillensis[3]				A toxochelyid.

See also

• Dinosaurs portal
• Paleontology portal

• List of dinosaur-bearing rock formations
• List of fossil sites

References

1. 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.
2. Chiappe, Luis; Lamb, James P.; Ericson, PER G. P. (2002). "New enantiornithine bird from the marine Upper Cretaceous of Alabama". Journal of Vertebrate Paleontology. 22 (1): 170–174. doi:10.1671/0272-4634(2002)022[0170:NEBFTM]2.0.CO;2.
3. 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.
4. Applegate, Shelton P.; Dale E. Russell (1970). The Vertebrate Fauna of the Selma Formation of Alabama. Part VII. Part VIII. The Mosasaurs The Fishes. Chicago: Field Museum of Natural History. pp. 387–430. OCLC 50419737.
5. Brownstein, Chase D. (2018-02-08). "The biogeography and ecology of the Cretaceous non-avian dinosaurs of Appalachia". Palaeontologia Electronica. 21 (1): 1–56. doi:10.26879/801. ISSN 1094-8074.
6. Albert Prieto-Márquez, Gregory M. Erickson & Jun A. Ebersole, 2016, "A primitive hadrosaurid from southeastern North America and the origin and early evolution of ‘duck-billed’ dinosaurs", Journal of Vertebrate Paleontology DOI:10.1080/02724634.2015.1054495
7. "Table 11.1," in Weishampel, et al. (2004). Page 213.
8. Kiernan, Caitlin R.; Ebersole, Jun A. (2023). "Two new plioplatecarpine mosasaurs (Mosasauridae; Plioplatecarpinae) of the genus Ectenosaurus from the Upper Cretaceous of North America". PaleoBios. 40 (13). doi:10.5070/P9401362375. ISSN 0031-0298.
9. 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.
10. Bardet N, Suberbiola P, Iarochene M, Bouyahyaoui F, Bouya B, Amaghzaz M (2005). "A new species of Halisaurus from the Late Cretaceous phosphates of Morocco, and the phylogenetical relationships of the Halisaurinae (Squamata: Mosasauridae)". Zoological Journal of the Linnean Society. 143 (3): 447–472. doi:10.1111/j.1096-3642.2005.00152.x.
11. "The relationships of Alabama halisaurine mosasaurs". Academia.edu. Retrieved 10 December 2021.