Stingrays are a group of sea rays, a type of cartilaginous fish. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae, Plesiobatidae, Urolophidae (stingarees), Urotrygonidae, Dasyatidae, Potamotrygonidae, Gymnuridae and Myliobatidae . There are about 220 known stingray species organized into 29 genera.
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates.
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.
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.
Paronychodon was a theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth from many disparate times and places but no other remains, and should be considered a form taxon.
Hypsirhophus is a genus of stegosaurian dinosaurs. It contains a single species, Hypsirhophus discurus, which is known only from a fragmentary specimen. The fossil consists of partial vertebrae from the back, three from the tail, and a piece of rib.
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.
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.
Saniwa is an extinct genus of varanid lizard that lived during the Eocene epoch. It is known from well-preserved fossils found in the Bridger and Green River Formations of Wyoming, United States. The type species S. ensidens was described in 1870 as the first fossil lizard known from North America. A second species, S.orsmaelensis, is recognised from remains found in Europe. It is a close relative of Varanus, the genus that includes monitor lizards.
Uintascorpio is an extinct genus of scorpion in the family Buthidae and containing the single species Uintascorpio halandrasorum. The species is known only from the Middle Eocene Parachute Member, part of the Green River Formation, in the Piceance Creek Basin, Garfield County, northwestern Colorado, USA.
The Bridger Formation is a geologic formation in southwestern Wyoming. It preserves fossils dating back to the Bridgerian and Uintan stages of the Paleogene Period. The formation was named by American geologist Ferdinand Vandeveer Hayden for Fort Bridger, which had itself been named for mountain man Jim Bridger. The Bridger Wilderness covers much of the Bridger Formation's area.
Eoprephasma is an extinct genus of stick insect in the susumaniid subfamily Susumaniinae known from a group of Eocene fossils found in North America. When first described there was a single named species, Eoprephasma hichensi.
Euglossopteryx is an extinct genus of bee in the family Apidae known from a fossil found in North America. There is one described species in the genus, Euglossopteryx biesmeijeri.
Gyaclavator is an extinct genus of lace bug in the family Tingidae known from a fossil found in North America. The genus contains a single species, Gyaclavator kohlsi.
Amia? hesperia is an extinct species of bony fish in the bowfin family, Amiidae. The species is known from fossils found in the early Eocene deposits of northern Washington state in the United States and southeastern British Columbia. The species is one of eight fish species identified in the Eocene Okanagan Highlands paleofauna.
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.
Morsoravis is an extinct genus of neoavian bird from the Early Eocene Fur Formation of Denmark. It contains a single named species, Morsoravis sedilis. Fossils of Morsoravis have also been found in the Green River Formation of Wyoming and possibly the Nanjemoy Formation of Virginia.
Libotonius is an extinct genus of percopsiform fish which lived during the early Eocene epoch and contains two species, the type species Libotonius blakeburnensis plus Libotonius pearsoni. Libotonius has been variously treated as part of the expanded Percopsidae family, or formerly as a member of the monotypic family Libotoniidae.
Erismatopterus is an extinct genus of percopsiform fish which lived during the early to middle Eocene epoch and containing the single species Erismatopterus levatus. A report of the genus in sediments of similar age in Washington State have been discredited. Erismatopterus is treated as part of the family Percopsidae, but formerly was the type genus of the extinct family Erismatopteridae. The genus is closely related to Amphiplaga of related lake sediments. Shoaling behavior has been reported from a mass mortality fossil of E. levatus and attributed as a predator-evasion response behavior.
