The Bladen Formation is a geologic formation from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(middle

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

) of

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

and

South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...

, USA. It is known for a plethora of terrestrial and aquatic vertebrate fossils, including

dinosaurs Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

and

mosasaur Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Ancient Greek, Greek ' meaning 'lizard') are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains wer ...

s.Various Contributors to the NCSM, et al. 2020. "NCSM Collection: Paleontology Database." It appears to be roughly concurrent with the Tuscaloosa Formation of

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

. 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 A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creat ...

in an

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

habitat, allowing for a mixture of freshwater, terrestrial, and marine fauna. An important locality is the former

Bladen County Bladen County ()
, from the North Carolina Collection's website at the

landfill annex in

Elizabethtown, North Carolina Elizabethtown is a town in Bladen County, North Carolina, United States. The population was 3,296 at the 2020 census. It is the county seat of Bladen County. History Some hold Elizabethtown is named for Elizabeth, the wife of George Carteret, ...

, which contains the richest known fauna from the formation. Another notable locality is near Quinby in

Florence County, South Carolina Florence County is a county located in the U.S. state of South Carolina. As of the 2020 census, its population was 137,059. Its county seat is Florence. Florence County is included in the Florence, SC Metropolitan Statistical Area. History F ...

, 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 The Tar Heel Formation, also known as the Coachman Formation in South Carolina, is a Late Cretaceous (early to middle Campanian-aged) Formation (geology), geologic formation in North Carolina and South Carolina, USA. It preserves fossils, includin ...

, which is often confused with. In North Carolina, it underlies the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

-aged

Peedee Formation The Peedee Formation is a Formation (geology), geologic formation in North Carolina, North and South Carolina. A marine deposit representing an inner Neritic zone, neritic environment, named for exposures along the Great Peedee River, it preserve ...

, 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 The Aguja Formation is a geological formation in North America, exposed in Texas, United States and Chihuahua and Coahuila in Mexico, whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered ...

from Texas.

Hybodonts

Sharks

Rays

Bony fish

Amphibians

Reptiles

Dinosaurs

Based on Brownstein (2018):

Crocodylomorphs

Turtles

Plesiosaurs

Squamates

Mammals

References

{{Reflist * Upper Cretaceous Series of North America Cretaceous geology of North Carolina Cretaceous geology of South Carolina Campanian Stage Deltaic deposits Sandstone formations of the United States Siltstone formations of the United States