Bladen Formation

Bladen Formation
Stratigraphic range: Middle Campanian ~77.5–76  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Unit of	Black Creek Group
Underlies	Donoho Creek Formation, Peedee Formation
Overlies	Tar Heel/Coachman Formation
Lithology
Primary	Sandstone, siltstone
Location
Region	North Carolina, South Carolina
Country	United States
Type section
Named for	Bladen County, North Carolina

The Bladen Formation is a geologic formation from the Late Cretaceous (middle Campanian) of North Carolina and South Carolina, USA. It is known for a plethora of terrestrial and aquatic vertebrate fossils, including dinosaurs and mosasaurs. ^[1] It appears to be roughly concurrent with the Tuscaloosa Formation of Alabama. ^[2]

Unlike many other Cretaceous geologic formations from eastern North America, which were deposited in entirely marine environments, the Bladen Formation appears to have been deposited in a former river delta in an estuarine habitat, allowing for a mixture of freshwater, terrestrial, and marine fauna. ^[3] An important locality is the former Bladen County landfill annex in Elizabethtown, North Carolina, which contains the richest known fauna from the formation. ^{[4] [5]} Another notable locality is near Quinby in Florence County, South Carolina, which also appears to have been deposited in a nonmarine environment with minor marine influence. ^[6]

It is deposited as a thin layer over the Tar Heel/Coachman Formation, which is often confused with. In North Carolina, it underlies the Maastrichtian-aged Peedee Formation, while in South Carolina it underlies the slightly younger Campanian-aged Donoho Creek Formation. ^[7]

Vertebrate paleobiota

Based on Crane (2011), Schwimmer et al (2015) and the Paleobiology Database: ^{[3] [6] [8]}

Cartilaginous fish

Based on Crane (2011) and Case et al (2019): ^{[3] [9]}

The chondrichthyan biota closely resembles that of the Aguja Formation from Texas. ^[9]

Hybodonts

Hybodonts of the Bladen Formation
Genus	Species	Location	Notes	Images
Lonchidion	L. babulskii	Elizabethtown, NC	A lonchidiid.
Meristodonoides	M. novojerseyensis	Elizabethtown, NC	A hybodontid.
	M. sp.

Sharks

Sharks of the Bladen Formation
Genus	Species	Location	Notes	Images
Archaeolamna	A. kopingensis	Elizabethtown, NC	An archaeolamnid mackerel shark.
Cantioscyllium	C. clementsi	Elizabethtown, NC	A nurse shark. Type locality of this species.
Cretalamna	C. appendiculata	Elizabethtown, NC	A megatooth shark.
	C. sp.
Cretorectolobus	C. sp.	Elizabethtown, NC	A wobbegong.
Galeorhinus	G. sp.	Elizabethtown, NC	A relative of the school shark.
Plicatoscyllium	P. globidens	Elizabethtown, NC	A nurse shark.
Protolamna	P. borodini	Elizabethtown, NC	An eoptolamnid mackerel shark.
Scapanorhynchus	S. texanus	Elizabethtown, NC	A goblin shark.
Squalicorax	S. kaupi	Elizabethtown, NC	A crow shark.
	S. cf. S. pristodontus
Squatina	S. sp.	Elizabethtown, NC	An angelshark. Sometimes assigned to the dubious species S. hassei. [9]

Rays

Rays of the Bladen Formation
Genus	Species	Location	Notes	Images
Anoxypristis	A. sp.	Elizabethtown, NC	A sawfish.
Borodinopristis	B. schwimmeri	Elizabethtown, NC	A sclerorhynchid sawskate. Type locality of B. shannoni. [10]
	B. shannoni
Brachyrhizodus	B. wichitaensis	Elizabethtown, NC	An eagle ray.
Dasyatis	D. cf. commercensis	Elizabethtown, NC	A whiptail stingray.
Ischyrhiza	I. avonicola	Elizabethtown, NC	A sclerorhynchid sawskate.
	I. mira
Onchopristis	O. sp.	Elizabethtown, NC	An onchopristid sawskate.
Ptychotrygon	P. triangularis	Elizabethtown, NC	A ptychotrygonid sawskate.
	P. vermiculata
Protoplatyrhina	P. sp.	Elizabethtown, NC	A hypsobatid ray. [11]
Pseudohypolophus	P. ellipsis	Elizabethtown, NC	A guitarfish.
Rhinobatos	R. casieri	Elizabethtown, NC	A guitarfish.
Rhombodus	R. binkhorsti	Elizabethtown, NC	A rhombodontid ray.
	R. laevis
Schizorhiza	S. sp.	Elizabethtown, NC	A schizorhizid sawskate.

Bony fish

Bony fish of the Bladen Formation
Genus	Species	Location	Notes	Images
Albula	A. sp.	Elizabethtown, NC	A bonefish.
Anomoeodus	A. phaseolus	Elizabethtown, NC	A pycnodontid pycnodont.
Cylindracanthus	C. sp	Elizabethtown, NC	A fish of uncertain affinities.
Enchodus	E. cf. petrosus	Elizabethtown, NC	An enchodontid aulopiform.
Hadrodus	H. priscus	Elizabethtown, NC	A hadrodontid fish (considered a pycnodont or a semionotiform)
Lepisosteus	L. sp.	Elizabethtown, NC	A gar.
Paralbula	P. casei	Elizabethtown, NC	A phyllodontid elopomorph.
Protosphyraena	P. sp.	Elizabethtown, NC	A pachycormid.
Xiphactinus	X. vetus	Elizabethtown, NC	An ichthyodectid ichthyodectiform.

Amphibians

Amphibians of the Bladen Formation
Genus	Species	Location	Notes	Images
Albanerpetontidae indet.		Elizabethtown, NC	An albanerpetontid. [12] [13]

Reptiles

Dinosaurs

Based on Brownstein (2018): ^[14]

Dinosaurs of the Bladen Formation
Genus	Species	Location	Notes	Images
" Coelosaurus " (="Ornithomimus")	"C." sp.	Elizabethtown, NC	An ornithomimosaur.
Hadrosauridae indet.		Elizabethtown, NC	A hadrosaur.
Tyrannosauroidea indet.		Elizabethtown, NC	A tyrannosauroid.

Crocodylomorphs

Crocodylomorphs of the Bladen Formation
Genus	Species	Location	Notes	Images
Borealosuchus	B. sp.	Elizabethtown, NC Quinby, SC	A eusuchian.
Deinosuchus	D. rugosus	Elizabethtown, NC Quinby, SC	An alligatoroid, one of the largest known crocodilians.
Gavialoidea indet.		Quinby, SC	A gavialoid.

Turtles

Turtles of the Bladen Formation
Genus	Species	Location	Notes	Images
Bothremys	B. sp.	Elizabethtown, NC	A bothremydid side-necked turtle.
Chedighaii	C. sp.	Elizabethtown, NC	A bothremydid side-necked turtle.
Euclastes	E. wielandi	Quinby, SC	A pancheloniid sea turtle.
" Trionyx "	"T." halophilus	Quinby, SC	A stem-softshell turtle, likely not an actual member of the genus Trionyx. Species names are nomina dubia .
	"T." priscus	Quinby, SC
	"T." sp.	Elizabethtown, NC

Plesiosaurs

Plesiosaurs of the Bladen Formation
Genus	Species	Location	Notes	Images
Elasmosauridae indet.		Elizabethtown, NC Quinby, SC	An elasmosaurid.

Squamates

Squamates of the Bladen Formation
Genus	Species	Location	Notes	Images
Coniophis	C. sp.	Elizabethtown, NC	An aquatic snake. [15]
Tylosaurus	T. sp.	Elizabethtown, NC	A tylosaurine mosasaur.

Mammals

Mammals of the Bladen Formation
Genus	Species	Location	Notes	Images
Cimolomys	C. sp.	Elizabethtown, NC	A multituberculate.

See also

• Earth sciences portal
• Paleontology portal
• Dinosaurs portal

• List of dinosaur-bearing rock formations

References

1. Various Contributors to the NCSM, et al. 2020. "NCSM Collection: Paleontology Database."
2. "Geolex — Bladen publications". ngmdb.usgs.gov. Retrieved 2024-11-13.
3. Crane, Cynthia Danielle (2011). VERTEBRATE PALEONTOLOGY AND TAPHONOMY OF THE LATE CRETACEOUS (CAMPANIAN) BLADEN FORMATION, BLADEN COUNTY, NORTH CAROLINA (Thesis).
4. "PBDB Collection". paleobiodb.org. Retrieved 2024-11-13.
5. Crane, Cynthia Danielle (2011). Vertebrate paleontology and taphonomy of the late Cretaceous (Campanian) Bladen Formation, Bladen County, North Carolina (Thesis).
6. Schwimmer, David R.; Sanders, Albert E.; Erickson, Bruce R.; Weems, Robert E. (2015). "A Late Cretaceous Dinosaur and Reptile Assemblage from South Carolina, Usa". Transactions of the American Philosophical Society. 105 (2): i–157. ISSN   0065-9746. JSTOR   24398224.
7. "Geolex — Bladen publications". ngmdb.usgs.gov. Retrieved 2024-11-13.
8. "PBDB Collection". paleobiodb.org. Retrieved 2024-11-15.
9. Case, Gerald R.; Cook, Todd D.; Kightlinger, Taylor (2019-07-31). "A description of a middle Campanian euselachian assemblage from the Bladen Formation of North Carolina, USA". Vertebrate Anatomy Morphology Palaeontology. 7: 69–82. doi: 10.18435/vamp29345 . ISSN   2292-1389.
10. Case, Gerard R.; Cook, Todd D.; Wilson, Mark V.H.; Borodin, Paul D. (2012). "A new species of the sclerorhynchid sawfish Borodinopristis from the Campanian (Upper Cretaceous) of North Carolina, USA" . Historical Biology. 24 (6): 592–597. doi:10.1080/08912963.2012.663367. ISSN   0891-2963.
11. "Protoplatyrhina sp. | Shark-References". shark-references.com. Retrieved 2024-11-15.
12. "PBDB Collection". paleobiodb.org. Retrieved 2024-11-13.
13. Gardner, James D.; DeMar, David G. (2013-12-01). "Mesozoic and Palaeocene lissamphibian assemblages of North America: a comprehensive review" . Palaeobiodiversity and Palaeoenvironments. 93 (4): 459–515. doi:10.1007/s12549-013-0130-z. ISSN   1867-1608.
14. Brownstein, Chase D. (2018-02-08). "The biogeography and ecology of the Cretaceous non-avian dinosaurs of Appalachia". Palaeontologia Electronica. Retrieved 2024-11-15.
15. "PBDB Collection". paleobiodb.org. Retrieved 2024-11-13.