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.
Monte Bolca is a lagerstätte near Verona, Italy that was one of the first fossil sites with high quality preservation known to Europeans, and is still an important source of fossils from the Eocene.
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.
Cladoselache is an extinct genus of shark-like chondrichthyan from the Late Devonian (Famennian) of North America. It was similar in body shape to modern lamnid sharks, but was not closely related to lamnids or to any other modern (selachian) shark. As an early chondrichthyan, it had yet to evolve traits of modern sharks such as accelerated tooth replacement, a loose jaw suspension, enameloid teeth, and possibly claspers.
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.
The deepwater stingray or giant stingaree is a species of stingray and the sole member of the family Plesiobatidae. It is widely distributed in the Indo-Pacific, typically over fine sediments on the upper continental slope at depths of 275–680 m (900–2,230 ft). This species reaches 2.7 m (8.9 ft) in length and 1.5 m (4.9 ft) in width. It has an oval pectoral fin disc with a long, flexible, broad-angled snout. Most of the entire latter half of its tail supports a distinctively long, slender, leaf-shaped caudal fin. Its coloration is dark above and white below, and its skin is almost completely covered by tiny dermal denticles.
Heliobatis is an extinct genus of stingray in the Myliobatiformes family Dasyatidae. At present the genus contains the single species Heliobatis radians.
Mene rhombea is an extinct perciform fish belonging to the family Menidae. During the Middle Eocene, about 48 to 40 mya, these fishes lived in the Tethys Ocean, a large tropical sea in the area corresponding to the current Mediterranean. This ocean was extended between the continents of Gondwana and Laurasia. At this time, where Monte Bolca is today, M. rhombea, and its relative, M. oblonga, lived in a tropical lagoon.
Edestus is an extinct genus of eugeneodontid holocephalian fish known from the Late Carboniferous (Pennsylvanian) of the United Kingdom, Russia, and the United States. Most remains consist of isolated curved blades or "whorls" that are studded with teeth, that in life were situated within the jaws. Edestus is a Greek name derived from the word edeste, in reference to the aberrant quality and size of the species' teeth. The largest species, E. heinrichi, has been conservatively estimated to reach greater than 6.7 m (22 ft) in length, around the size of the largest known great white shark, possibly making it the largest marine predator to have ever existed up to that point.
The yellow shovelnose stingaree is a little-known species of stingray in the family Urolophidae, endemic to the outer continental shelf off Western Australia at a depth of 100–210 m (330–690 ft). Growing to 39 cm (15 in) long, this species has an oval pectoral fin disc with a rather elongated, triangular snout, and a short tail with a caudal fin but no dorsal fin. There are prominent lobes outside of its nostrils, and a skirt-shaped flap of skin with a deeply fringed trailing margin in between. Above, this ray is an almost completely uniform light to dark yellow color, which darkens on the caudal fin. The International Union for Conservation of Nature (IUCN) assesses the yellow shovelnose stingaree as least concern, as there is minimal fishing within its range.
The New Ireland stingaree or black-spotted stingaree, is a species of stingray in the family Urolophidae, known only from a single juvenile male 17.4 cm (6.9 in) long, collected in the Bismarck Archipelago. This species has an oval pectoral fin disc with tiny eyes and a rectangular curtain of skin between the nostrils. Its tail is fairly long and terminates in a leaf-shaped caudal fin, and lacks a dorsal fin. Uniquely among stingarees, it has rows of sharp spinules on the posterior portion of its back and the base of its tail. Its dorsal coloration is brown with dark spots. The International Union for Conservation of Nature (IUCN) has listed this ray as Data Deficient, pending more information.
Urolophus is a genus of round rays mostly native to the western Pacific Ocean and the Indian Ocean, though one species occurs in the Pacific waters of the Mexican coast. Müller and Henle erected Urolophus in an 1837 issue of Bericht Akademie der Wissenschaften zu Berlin. The name is derived from the Greek oura, meaning "tail", and lophos, meaning "crest". In Urolophus, the outer rims of the nostrils are not enlarged into lobes, but may form a small knob at the back.
The Chesterfield Island stingaree or Deforge's stingaree is a little-known species of stingray in the family Urolophidae, endemic to the continental slope off the Chesterfield Islands. Reaching 34 cm (13 in) long, it has a rounded, diamond-shaped pectoral fin disc colored plain brown above and pale below, with a short head. There is a narrow, skirt-shaped curtain of skin between its nostrils. Its tail is relatively long and terminates in a leaf-shaped caudal fin; there are no dorsal fin or lateral skin folds. This species has been listed under Least Concern by the International Union for Conservation of Nature (IUCN), as there is little fishing activity within its range.
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.
The Tumbes round stingray is a little-known species of round ray, family Urolophidae, known only from two immature male specimens collected from estuarine waters at depths of 1–2 m, and a third specimen collected in 2006 near mangroves. Its range appears to be limited to coastal waters off Tumbes in northern Peru, where it is found partially buried in sand or mud. The larger of the original two specimens measured 40.4 cm long and the smaller 15.7 cm.
Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.
Bahndwivici is an extinct genus of lizard known from a nearly complete and articulated skeleton discovered in rocks of the Green River Formation of Wyoming, United States. The skeleton is very similar to that of the modern Chinese crocodile lizard, Shinisaurus.
Afairiguana avius is an extinct iguanid lizard known from a nearly complete and articulated skeleton discovered in rocks of the Early Eocene-aged Green River Formation of Wyoming, United States. As of the initial description, the skeleton represents the oldest complete iguanian from the Western Hemisphere, and is the oldest representative of the extant iguanid family of anoles, Polychrotidae.
Calciavis is an extinct genus of bird from the Eocene of Wyoming. It is a lithornithid, a member of a lineage of flying palaeognaths, distantly related to modern ratites. Like many other fossils from the Green River Formation, its are exceptionally well preserved, bearing impressions of skin and feathers.
Lessiniabatis is an extinct genus of highly unusual stingray from the Early Eocene of Italy. It contains a single species, L. aenigmatica. It is known from three specimens, one nearly complete, from the famous Monte Bolca lagerstätte.
