[F] Hell Creek Formation - Montana - North Dakota - South Dakota - US
Montana - North Dakota - South Dakota - US
The Hell Creek Formation of Montana, North Dakota and South Dakota represents deposition of fluvial nonmarine sediments along the eastern margin of an interior seaway. The desiments are primarily sandstones, siltstones, and mudstones. The Hell Creek Formation is allmost entirely Late Cretaceous in age but the upper few meters may be Paleocene. Furhter south a layer of the same age is found and goes by another name Lance Formation.
In Canada, correlative rock layers are the Frenchman Formation and the Scollard Formation. All of these these units were deposited by ancient rivers that flowed eastward into a large inland sea that ran from north-central Canada to the Gulf of Mexico. The rock layer that underlies the Hell Creek Formation is called the [Fox Hills Formation], and the overlying layer is called the [Tullock Formation] (Paleocene). In the Dakotas, the overlying formation is called the [Ludlow Formation]. The K/Pg boundary occurs as a discontinuous but distinct thin marker bed within the Hell Creek Formation.
Albertosaurus (Clevelanotyrannus) lancensis - Montana - Tyrannosaurinae Albertosaurini - Cretaceous Late Maastrichtian
Albertosaurus (Nanotyrannus) lancensis - Montana - Tyrannosaurinae Albertosaurini - Cretaceous Late Maastrichtian
Albertosaurus lancensis - Montana - Tyrannosaurinae Albertosaurini - Cretaceous Late Maastrichtian
Albertosaurus megagracilis - Montana - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian
Anatotitan copei - Montana, South Dakota - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian
Ankylosaurus magniventris - Montana - Ankylosauria Ankylosauridae - Cretaceous Late, Maastrichtian
Aublysodon mirandus - Montana - Tyrannosauria Tyrannosauridae - Cretaceous Late Campanian Maastrichtian
Aublysodon molnari - Montana - Tyrannosauridae Aublysodontinae - Cretaceous Late Campanian
Avisaurus archibaldi ~/~ - Montana - Ornithothoraces Enantiornithes - Cretaceous Late Campanian Maastrichtian
Bugenasaura infernalis - South Dakota - Ornithopoda Hypsilophodontidae - Cretaceous Late Maastrichtian
Claosaurus annectens - Montana, South Dakota - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian
Dinotyrannus megagracilis - Montana - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian
Dracorex hogwartsia - South Dakota - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Campanian Maastrichtian
Edmontonia sp (1) - Montana, South Dakota - Not considered dinosaur
Edmontonia sp (3) - Montana, South Dakota - Ankylosauria Nodosauridae - Cretaceous Late Maastrichtian
Edmontosaurus annectens - Montana, South Dakota - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian
Edmontosaurus regalis - North Dakota, South Dakota - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian
Elmisaurus elegans - Montana - Oviraptorosauria Caenagnathidae - Cretaceous Late Campanian Maastrichtian
Gorgosaurus lancensis - Montana - Tyrannosaurinae Albertosaurini - Cretaceous Late Maastrichtian
Nanotyrannus lancensis - Montana - Tyrannosaurinae Albertosaurini - Cretaceous Late Maastrichtian
Orcomimus - South Dakota - Ornithomimidae Nomen Nudem - Cretaceous Late Maastrichtian
Pachycephalosaurus wyomingensis - Montana, South Dakota - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian
Parasaurolophus walkeri - Montana - Hadrosauridae Lambeosaurinae - Cretaceous Late Campanian
Paronychodon lacustris - Montana - Troodontidae Nomina Dubia - Cretaceous Late Campanian Maastrichtian
Ricardoestesia isosceles - North Dakota, South Dakota - Tetanurae Coelurosauria - Cretaceous Late Campanian
Sphaerotholus buchholtzae - Montana - Pachycephalosauridae [Pachycephalosaurinae] - Cretaceous Late Maastrichtian
Stegoceras edmontonense - Montana - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian
Stenotholus kohleri - Montana - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian
Stygimoloch spinifer (incl. Stenotholus kohleri) - Montana - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian
Stygivenator molnari - Montana - Tyrannosauridae Aublysodontinae - Cretaceous Late Campanian
Tatankaceratops sacrisonorum - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian
Thescelosaurus garbanii - Montana - Ornithopoda Hypsilophodontidae - Cretaceous Late Campanian Maastrichtian
Thescelosaurus neglectus - Montana, South Dakota - Ornithopoda Hypsilophodontidae - Cretaceous Late Campanian Maastrichtian
Leptoceratops cf. gracilis - Montana - Neoceratopia Protoceratopidae - Cretaceous Late Maastrichtian
Thescelosaurus sp. \\\"\\\" NN