The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
The Laramie Formation is a geologic formation of Late Cretaceous (Maastrichtian) age, named by Clarence King in 1876 for exposures in northeastern Colorado, in the United States. It was deposited on a coastal plain and in coastal swamps that flanked the Western Interior Seaway. It contains coal, clay and uranium deposits, as well as plant and animal fossils, including dinosaur remains.
The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah. The formation was named for Cedar Mountain in northern Emery County, Utah, where William Lee Stokes first studied the exposures in 1944.
The Cloverly Formation is a geological formation of Early Cretaceous age that is present in parts of Montana, Wyoming, Colorado and Utah in the western United States. It was named for a post office on the eastern side of the Bighorn Basin in Wyoming by N.H. Darton in 1904. The sedimentary rocks of formation were deposited in floodplain environments and contain vertebrate fossils, including a diverse assemblage of dinosaur remains. In 1973, the Cloverly Formation Site was designated as a National Natural Landmark by the National Park Service.
The Dakota is a sedimentary geologic unit name of formation and group rank in Midwestern North America. The Dakota units are generally composed of sandstones, mudstones, clays, and shales deposited in the Mid-Cretaceous opening of the Western Interior Seaway. The usage of the name Dakota for this particular Albian-Cenomanian strata is exceptionally widespread; from British Columbia and Alberta to Montana and Wisconsin to Colorado and Kansas to Utah and Arizona. It is famous for producing massive colorful rock formations in the Rocky Mountains and the Great Plains of the United States, and for preserving both dinosaur footprints and early deciduous tree leaves.
The Wayan Formation is a geological formation in Idaho whose strata date back to the latest Early Cretaceous and the earliest Late Cretaceous. Dinosaur, other reptile, mammal, and micro and macro-floral remains are among the fossils that have been recovered from the formation. The lack of extensive outcrops, limited geographic extent, and extreme structural deformation have limited paleontological explorations of the Wayan.
The Foremost Formation is a stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of Foremost and is known primarily for its dinosaur remains and other fossils.
The North Horn Formation is a widespread non-marine sedimentary unit with extensive outcrops exposed in central and eastern Utah. The formation locally exceeds 3,600 feet (1,100 m) in thickness and is characterized by fluvial, lacustrine, and floodplain dominated systems, representing a terrestrial, high energy, depositional environment. The sediments date from Late Cretaceous (Maastrichtian) to early Paleocene in age and include the K-Pg extinction event boundary; however, this boundary is extremely difficult to locate and there is no strong stratigraphic evidence available that indicates a specific marker bed such as an iridium rich clay layer. Thus far, the only visible evidence is represented in the form of faunal turnover from dinosaur to mammal-dominated fossil assemblages. Taxa from the Cretaceous part of the formation include squamates, testudines, choristoderes, crocodyliforms, sharks, bony fishes, amphibians, mammals, dinosaurs, eggshell fragments, trace fossils, mollusks, plant macrofossils, such as wood fragments, and palynomorphs.
The Denver Formation is a geological formation that is present within the central part of the Denver Basin that underlies the Denver, Colorado, area. It ranges in age from latest Cretaceous (Maastrichtian) to early Paleocene, and includes sediments that were deposited before, during and after the Cretaceous-Paleogene boundary event.
The Arapahoe Formation is a geological formation of latest Cretaceous (Maastrichtian) age that is present within the Denver Basin that underlies the Denver, Colorado, area. The formation includes fossil leaves and dinosaur remains, although none of the latter have yet been referred to a specific genus. It also includes aquifers that are important sources of water for the area.
The Crevasse Canyon Formation is a coal-bearing Cretaceous geologic formation in New Mexico and Arizona.
The Pictured Cliffs Formation is a Campanian geologic formation in the San Juan Basin of New Mexico. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
The Point Lookout Sandstone is a Cretaceous bedrock formation occurring in New Mexico and Colorado.
The Ringbone Formation is a Campanian geologic formation in southwestern New Mexico.
The Tropic Shale is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation, including Nothronychus graffami. The Tropic Shale is a stratigraphic unit of the Kaiparowits Plateau of south central Utah. The Tropic Shale was first named in 1931 after the town of Tropic where the Type section is located. The Tropic Shale outcrops in Kane and Garfield counties, with large sections of exposure found in the Grand Staircase-Escalante National Monument.
The Bissett 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 Mowry Shale is an Early Cretaceous geologic formation. The formation was named for Mowrie Creek, northwest of Buffalo in Johnson County, Wyoming.
The Ferron Sandstone Member of the Mancos Shale is a geologic unit in Utah. It preserves fossils dating back to the Cretaceous period; and more specifically the middle Turonian.
The Price River Formation is a geologic formation in Utah. It preserves fossils dating back to the Cretaceous period. The Price River Formation is approximately 200 metres (660 ft) thick at its type locality and consists of cliff-forming sandstone and siltstone visible in the Book Cliffs.
The Mesaverde Group is a Late Cretaceous stratigraphic group found in areas of Colorado, New Mexico, Utah, and Wyoming, in the Western United States.
