Bladen Formation | |
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Stratigraphic range: Middle Campanian ~ | |
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]
Based on Crane (2011), Schwimmer et al (2015) and the Paleobiology Database: [3] [6] [8]
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 of the Bladen Formation | |||||
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Genus | Species | Location | Notes | Images | |
Lonchidion | L. babulskii | Elizabethtown, NC | A lonchidiid. | ||
Meristodonoides | M. novojerseyensis | Elizabethtown, NC | A hybodontid. | ||
M. sp. |
Sharks of the Bladen Formation | |||||
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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 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 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 of the Bladen Formation | ||||||
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Genus | Species | Location | Notes | Images | ||
Albanerpetontidae indet. | Elizabethtown, NC | An albanerpetontid. [12] [13] |
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 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 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 of the Bladen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Notes | Images | ||
Elasmosauridae indet. | Elizabethtown, NC Quinby, SC | An elasmosaurid. |
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 of the Bladen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Notes | Images | ||
Cimolomys | C. sp. | Elizabethtown, NC | A multituberculate. |
Cimolomys is a mammal genus from the Upper Cretaceous of North America. It was a member of the extinct order Multituberculata within the suborder Cimolodonta and family Cimolomyidae.
Deinosuchus is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos (δεινός), "terrible", and soukhos (σοῦχος), "crocodile". The first remains were discovered in North Carolina in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.
Lophorhothon is a genus of hadrosauroid dinosaur from the Late Cretaceous of Alabama and North Carolina. It was the first genus of dinosaur discovered in Alabama, in the United States.
The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between 82.4 Ma and 74.4 Ma, during Campanian time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas.
The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase–Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet thick, and is Campanian in age. This Upper Cretaceous formation was formed from alluvial floodplains of large rivers in coastal southern Laramidia; sandstone beds are the deposit of rivers, and mudstone beds represent floodplain deposits. It is fossiliferous, with most specimens from the lower half of the formation, but exploration is only comparatively recent, with most work being done since 1982. It has been estimated that less than 10% of the Kaiparowits formation has been explored for fossils. The Natural History Museum of Utah has conducted most fieldwork.
Coriops is an extinct genus of freshwater osteoglossomorph fish, possibly a hiodontiform, with a single species known from the Late Cretaceous of western North America.
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.
The Marshalltown Formation is a Mesozoic geologic formation. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.
The Hornerstown Formation is a latest Cretaceous to early Paleocene-aged geologic formation in New Jersey. It preserves a variety of fossil remains, including those of dinosaurs, and contains direct evidence of the mass mortality that occurred at the Cretaceous-Paleogene boundary.
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The Black Creek Group is a Late Cretaceous -aged geologic group in the southeastern United States, where it is known from the coastal plain of North Carolina and South Carolina. Deposited in brackish or nearshore marine conditions, it preserves fossils, including a diversity of dinosaurs and marine reptiles.
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