The John Day Formation is a series of rock strata exposed in the Picture Gorge district of the John Day River basin and elsewhere in north-central Oregon in the United States. The Picture Gorge exposure lies east of the Blue Mountain uplift, which cuts southwest–northeast through the Horse Heaven mining district northeast of Madras. Aside from the Picture Gorge district, which defines the type, the formation is visible on the surface in two other areas: another exposure is in the Warm Springs district west of the uplift, between it and the Cascade Range, and the third is along the south side of the Ochoco Mountains. All three exposures, consisting mainly of tuffaceous sediments and pyroclastic rock rich in silica, lie unconformably between the older rocks of the Clarno Formation below and Columbia River basalts above.
Protohippus is an extinct three-toed genus of horse. It was roughly the size of a modern donkey. Fossil evidence suggests that it lived during the Late Miocene, from about 13.6 Ma to 5.3 Ma.
Neohipparion is an extinct genus of equid, from the Neogene of North America and Central America. Fossils of this horse have been found in Texas, Florida, Kansas, South Dakota, Montana, Nevada, Alabama, Oregon, and Mexico. This prehistoric species of equid grew up to lengths of 4.5 to 5 ft long. In Florida, Neohipparion lived in a wooded grassland savanna environment during the dry season but moved to a wet environment when it came time to mate. Speaking of mating, the average age of death for a newborn colt was 3.5 years, with a juvenile mortality rate of 64% during its first 2 years of existence. Its diet consisted of grasses, C3 and C4 plants.
Pseudhipparion is an extinct genus of three-toed horse endemic to North America during the Miocene. They were herding animals whose diet consisted of C3 plants. Fossils found in Georgia and Florida indicate that it was a lightweight horse, weighing up to 90 pounds. In 2005, fossils were unearthed in Oklahoma. Seven species of Pseudhipparion are known from the fossil record which were very small, following the trend of Bergmann's rule.
Nannippus is an extinct genus of three-toed horse endemic to North America during the Miocene through Pleistocene, about 13.3—1.8 million years ago (Mya), living around 11.5 million years. This ancient species of three-toed horse grew up to 3.5 feet and weighed between 165 pounds to 199 pounds, which was around the same size as a domestic sheep.
Cormohipparion is an extinct genus of horse belonging to the tribe Hipparionini that lived in North America during the late Miocene to Pliocene. They grew up to 3 feet long.
The Irdin Manha Formation is a geological formation from the Eocene located in Inner Mongolia, China, a few kilometres south of the Mongolian border.
Phlaocyon annectens is an extinct species of the genus Phlaocyon, belonging to the subfamily Borophaginae and tribe Phlaocyonini, a canid endemic to central and western North America from the Late Oligocene to Early Miocene living 24.6—20.8 mya and existed for approximately 4.2 million years.
The Carlile Shale is a Turonian age Upper/Late Cretaceous series shale geologic formation in the central-western United States, including in the Great Plains region of Colorado, Kansas, Nebraska, New Mexico, North Dakota, South Dakota, and Wyoming.
Paleontology in Kansas refers to paleontological research occurring within or conducted by people from the U.S. state of Kansas. Kansas has been the source of some of the most spectacular fossil discoveries in US history. The fossil record of Kansas spans from the Cambrian to the Pleistocene. From the Cambrian to the Devonian, Kansas was covered by a shallow sea. During the ensuing Carboniferous the local sea level began to rise and fall. When sea levels were low the state was home to richly vegetated deltaic swamps where early amphibians and reptiles lived. Seas expanded across most of the state again during the Permian, but on land the state was home to thousands of different insect species. The popular pterosaur Pteranodon is best known from this state. During the early part of the Cenozoic era Kansas became a savannah environment. Later, during the Ice Age, glaciers briefly entered the state, which was home to camels, mammoths, mastodons, and saber-teeth. Local fossils may have inspired Native Americans to regard some local hills as the homes of sacred spirit animals. Major scientific discoveries in Kansas included the pterosaur Pteranodon and a fossil of the fish Xiphactinus that died in the act of swallowing another fish.
The Ogallala Formation is a Miocene to early Pliocene geologic formation in the central High Plains of the western United States and the location of the Ogallala Aquifer. In Nebraska and South Dakota it is also classified as the Ogallala Group. Notably, it records the North American Land Mammal Ages (NALMAs) Hemphillian, Clarendonian, and Barstovian. It also includes an excellent record of grass seeds and other plant seeds, which can be used for biostratigraphic dating within the formation. The Ogallala Formation outcrops of Lake Meredith National Recreation Area preserve fish fossils. Similar specimens from the same unit are found at Alibates Flint Quarries National Monument in Texas.
The Alachua Formation is a Miocene geologic formation in Florida. The claystones, sandstones and phosphorites of the formation preserve many fossils of mammals, birds, reptiles and fish, among others megalodon.
The Ash Hollow Formation of the Ogallala Group is a geological formation found in Nebraska and South Dakota. It preserves fossils dating back to the Neogene period. It was named after Ash Hollow, Nebraska and can be seen in Ash Hollow State Historical Park. Ashfall Fossil Beds State Historical Park is within this formation.
The Rosebud Formation is a geologic formation of cemented pink silt in Nebraska and South Dakota, dating to the early middle Miocene epoch of the Neogene period. Possibly named for its color, no type location has been set for this unit, but it is associated with the Valentine Formation along the Niobrara River. The fine silt of the formation forms an aquitard beneath the Ogallala Aquifer carried by the Valentine Formation. Many springs from the Valentine sands flow down the Rosebud outcrop into the Niobrara River.
The Sharps Formation is a geologic formation in South Dakota. It preserves fossils dating back to the Paleogene.
The Marsland Formation is a geologic formation in Nebraska. It preserves fossils dating back to the Neogene period.
The Astoria Formation is a geologic formation in Washington state & Oregon. It preserves fossils dating back to the early to middle Miocene.
The Dove Spring Formation is a geologic formation in the western Mojave Desert of California. It preserves fossils dating back to the Miocene epoch of the Neogene period.
Hyperailurictis is an extinct genus of felid from Miocene North America. The Hyperailurictis species are Pseudaelurus-grade felids and thought to be the first felids in the Americas.