The Wind River Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

in the

Wind River Basin The Wind River Basin is a semi-arid intermontane foreland basin in central Wyoming, United States. It is bounded by Laramide orogeny, Laramide uplifts on all sides. On the west is the Wind River Range and on the North are the Absaroka Range and t ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

dating back to the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

. A recent study by Stanford suggests that

fracking Fracking (also known as hydraulic fracturing, fracing, hydrofracturing, or hydrofracking) is a well stimulation technique involving the fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure inje ...

Fossil content

Mammals

Apatotheres

Cimolestans

Leptictids

Primatomorphs

Rodents

Ungulates

Reptiles

Squamates

Invertebrates

Insects

Plants

See also

References