Hell Creek Formation
What Is It?
- The Hell Creek Formation is an intensively-studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana.
- It is a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the end of the Cretaceous period and the beginning of the Paleogene period by fluvial activity in fluctuating river channels and deltas and very occasional swamp deposits along the eastern continental margin fronting the late Cretaceous Western Interior Seaway.
Animals/Species Found in the Area
- Many animals including dinosaurs lived in the Hell Creek Formation. The Hell Creek Formation has world-famous dinosaur fossil sites. Fossils are found of sea creatures from the recession and adjacent inland sea at that time. Vertebrates include dinosaurs, pterosaurs, crocodiles, champsosaurs, lizards, snakes, turtles, frogs andsalamanders. Remains of fishes and mammals have also been found in the Hell Creek Formation.
- Notable dinosaur finds include Tyrannosaurus and Triceratops. Ornithomimids as well, Caenagnathidae, a variety of smalltheropods, Pachycephalosaurs, Crocodylomorphs, and Squamates
Hell Creek Formation - Video
Dinosaur Fossils--Hell Creek Formation in Montana