The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and shales. Based on argon radiometric dating, the formation is Eocene in age and has been interpreted as a lake environment. The fossils have been preserved because of the interaction of the volcanic ash from the nearby Thirtynine Mile volcanic field with diatoms in the lake, causing a diatom bloom. As the diatoms fell to the bottom of the lake, any plants or animals that had recently died were preserved by the diatom falls. Fine layers of clays and muds interspersed with layers of ash form "paper shales" holding beautifully-preserved fossils. The Florissant Fossil Beds National Monument is a national monument established to preserve and study the geology and history of the area.
Knightia is an extinct genus of clupeid bony fish that lived in the freshwater lakes and rivers of North America and Asia during the Eocene epoch. The genus was erected by David Starr Jordan in 1907, in honor of the late University of Wyoming professor Wilbur Clinton Knight, "an indefatigable student of the paleontology of the Rocky Mountains." It is the official state fossil of Wyoming, and the most commonly excavated fossil fish in the world.
Fossil Butte National Monument is a United States National Monument managed by the National Park Service, located 15 miles (24 km) west of Kemmerer, Wyoming, United States. It centers on an assemblage of Eocene Epoch animal and plant fossils associated with Fossil Lake—the smallest lake of the three great lakes which were then present in what are now Wyoming, Utah, and Colorado. The other two lakes were Lake Gosiute and Lake Uinta. Fossil Butte National Monument was established as a national monument on October 23, 1972.
Driftwood Canyon Provincial Park is a provincial park in British Columbia, Canada. Driftwood Canyon Provincial Park covers 23 ha of the Bulkley River Valley, on the east side of Driftwood Creek, a tributary of the Bulkley River, 10 km northeast of the town of Smithers. The park is accessible from Driftwood Road from Provincial Highway 16. It was created in 1967 by the donation of the land by the late Gordon Harvey (1913–1976) to protect fossil beds on the east side of Driftwood Creek. The beds were discovered around the beginning of the 20th century. The park lands are part of the asserted traditional territory of the Wet'suwet'en First Nation.
Heliobatis is an extinct genus of stingray in the Myliobatiformes family Dasyatidae. At present the genus contains the single species Heliobatis radians.
Diplomystus is an extinct genus of freshwater clupeomorph fish distantly related to modern-day extant herrings, alewives, and sardines. The genus was first named and described by Edward Drinker Cope in 1877. There are seven species of Diplomystus: D. dentatus, D. birdii, D. dubetreiti, D. shengliensis, D. kokuraensis, D. primotinus, and D. altiformis.
Priscacara, is a genus of extinct temperate bass described from Early to Middle Eocene fossils. It is characterized by a sunfish-like body and its stout dorsal and anal spines. The genus is best known from the Green River Formation of Wyoming, Utah and Colorado. Mass deaths of Priscacara suggest it formed schools.
Amphiperca is an extinct genus of prehistoric freshwater perciform fish that lived from the early to middle Eocene of Europe. It has one known species, A. multiformis, known from the famous Messel Pit of Germany. Indeterminate remains are known from concurrent formations in Occitanie, France. It was a predatory fish that is known to have fed on Thaumaturus and Rhenanoperca.
Amyzon is an extinct genus belonging to the sucker family Catostomidae first described in 1872 by E. D. Cope. There are six valid species in the genus. Amyzon are found in North American fossil sites dated from the Early Eocene in Montana and Washington USA, as well as the British Columbian sites at McAbee Fossil Beds, Driftwood Canyon, and the "Horsefly shale", as well as Early Oligocene sites in Nevada USA. One Middle Eocene species is known from the Xiawanpu Formation of China. The Ypresian species A. brevipinne of the Allenby Formation was redescribed in 2021 and moved to a separate monotypic genus Wilsonium.
Elimia tenera, formerly known as Goniobasis tenera, is an extinct species of freshwater snail with an operculum, in the aquatic gastropod mollusk family Pleuroceridae. This species flourished during the Eocene and is now known only from the fossil record. The genus name Elimia was restored to this species in 1975; formerly it was placed in Goniobasis.
Asterotrygon is an extinct genus of stingray from the Eocene Green River Formation in Wyoming. Several complete skeletons representing juveniles, adults, males and females have been uncovered from the late early Eocene Fossil Butte Member of the formation. The type and only species, A. maloneyi, was named in 2004 on the basis of these fossils. Another stingray, Heliobatis, is also known from the formation. Asterotrygon is a primitive stingray closely related to the living family Urolophidae whose ancestors likely originated in the Indo-Pacific. It lived in Fossil Lake, a body of water that existed in a subtropical mountainous region for only about 2 million years.
Paleontology in Wyoming includes research into the prehistoric life of the U.S. state of Wyoming as well as investigations conducted by Wyomingite researchers and institutions into ancient life occurring elsewhere.
Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. More than 3,300 different kinds of fossil organisms have been found in the state. Of these more than 700 of these were new to science and more than 100 of those were type species for new genera. During the early Paleozoic, southern and western New Mexico were submerged by a warm shallow sea that would come to be home to creatures including brachiopods, bryozoans, cartilaginous fishes, corals, graptolites, nautiloids, placoderms, and trilobites. During the Ordovician the state was home to algal reefs up to 300 feet high. During the Carboniferous, a richly vegetated island chain emerged from the local sea. Coral reefs formed in the state's seas while terrestrial regions of the state dried and were home to sand dunes. Local wildlife included Edaphosaurus, Ophiacodon, and Sphenacodon.
Crossopholis is an extinct fish known from the early Eocene (Ypresian) of North America, approximately 52 million years ago. It is a close relative of the contemporary American paddlefish, belonging to the paddlefish family Polyodontidae.
The Laguna del Hunco Formation or Laguna del Hunco Tuff is a localized Early Eocene fossiliferous geological formation of the Cañadón Asfalto Basin in central Patagonia, Argentina. The 170 metres (560 ft) thick formation comprises tuffaceous mudstones and sandstones deposited in a crater lake environment and crops out at Laguna del Hunco in the northwestern Chubut Province.
Hiodon woodruffi is an extinct species of bony fish in the mooneye family, Hiodontidae. The species is known from fossils found in the early Eocene deposits of northern Washington state in the United States and late Eocene deposits in northwestern Montana. The species was first described as Eohiodon woodruffi. H. woodruffi is one of two Eocene Okanagan Highlands mooneye species, and one of five fish identified in the Klondike Mountain Formation.
Cockerellites is a genus of extinct temperate bass described from early Eocene-aged fossils found in the Green River Formation of Wyoming. It is characterized by a sunfish-like body and its stout dorsal and anal spines. The type species, C. liops, was originally named as a species of Priscacara by Edward Drinker Cope upon creating the genus in 1877, but P. liops was moved to the newly created genus Cockerellites by D. Jordan and H. Hanibal in 1923. Some authors, such as Whitlock (2010), still consider Cockerellites liops as a species of Priscacara.
The Eocene Okanagan Highlands or Eocene Okanogan Highlands are a series of Early Eocene geological formations which span a 1,000 km (620 mi) transect of British Columbia, Canada, and Washington state, United States. Known for a highly diverse and detailed plant and animal paleobiota the paleolake beds as a whole are considered one of the great Canadian Lagerstätten. The paleobiota represented are of an upland subtropical to temperate ecosystem series immediately after the Paleocene–Eocene thermal maximum, and before the increased cooling of the middle and late Eocene to Oligocene. The fossiliferous deposits of the region were noted as early as 1873, with small amounts of systematic work happening in the 1870–1920s on British Columbian sites, and 1920–1930s for Washington sites. Focus and more detailed descriptive work on the Okanagan Highland sites started in the late 1960s.
The paleofauna of the Eocene Okanagan Highlands consists of Early Eocene arthropods, vertebrates, plus rare nematodes and molluscs found in geological formations of the northwestern North American Eocene Okanagan Highlands. The highlands lake bed series' as a whole are considered one of the great Canadian Lagerstätten. The paleofauna represents that of a late Ypresian upland temperate ecosystem immediately after the Paleocene-Eocene thermal maximum, and before the increased cooling of the middle and late Eocene to Oligocene. The fossiliferous deposits of the region were noted as early as 1873, with small amounts of systematic work happening in the 1880-90s on British Columbian sites, and 1920-30s for Washington sites. Focus and more detailed descriptive work on the Okanagan Highlands site started in the last 1970's. Most of the highlands sites are preserved as compression-impression fossils in "shales", but also includes a rare permineralized biota and an amber biota.
