Bladen Formation

Bladen Formation
Stratigraphic range: Middle Campanian
~77.5–76 Ma
TypeFormation
Unit ofBlack Creek Group
UnderliesDonoho Creek Formation, Peedee Formation
OverliesTar Heel/Coachman Formation
Lithology
PrimarySandstone, siltstone
Location
RegionNorth Carolina, South Carolina
CountryUnited States
Type section
Named forBladen 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. It appears to be roughly concurrent with the Tuscaloosa Formation of Alabama.

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. An important locality is the former Bladen County landfill annex in Elizabethtown, North Carolina, which contains the richest known fauna from the formation. 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.

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.

Vertebrate paleobiota

Based on Crane (2011), Schwimmer et al (2015) and the Paleobiology Database:

Cartilaginous fish

Based on Crane (2011) and Case et al (2019):

The chondrichthyan biota closely resembles that of the Aguja Formation from Texas.

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.

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.
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.
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.

Reptiles

Dinosaurs

Based on Brownstein (2018):

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.
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

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. 1 2 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. 1 2 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. 1 2 3 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.