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Ptycholepis
''Ptycholepis'' is an extinct genus of prehistoric ray-finned fish having the head and opercular bones ornamented with ridges of ganoin, minute teeth, and thick scales (which are much longer than deep and are grooved longitudinally on the outer side). ''Ptycholepis'' belongs to the family Ptycholepidae (= Boreosomidae/Chungkingichthyidae). Other genera of this family are '' Acrorhabdus'' (Spitsbergen, Early Triassic), ''Ardoreosomus'' (Nevada, United States; Early Triassic), ''Boreosomus'' (global, Early Triassic), '' Chungkingichthys'' (China, Early Triassic) and ''Yuchoulepis'' (China, Early Triassic). A typical feature of this family is the dorsal fin, which inserts at the level of the pelvic fins in the front part of the body. Other characters include the striated skull bones and scales, and the small teeth. File:Ptycholepis bollensis.jpg, ''Ptycholepis bollensis'' File:Ptycholepis bollensis - Holzmaden.jpg, ''Ptycholepis bollensis'' File:Ptycholepis bollensis - Lyme Regis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptycholepiformes
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. The order includes the genera '' Acrorhabdus'', ''Ardoreosomus'', ''Boreosomus'', '' Chungkingichthys'', '' Ptycholepis'', and '' Yuchoulepis''. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae. Ptycholepiformes had a widespread distribution during the Early Triassic, but were restricted to mainly Europe and North America afterwards. They are known from both marine and freshwater deposits. Appearance Typical features of ptycholepiforms are the fusiform body covered in rhombic ganoid scales, the anterior position of the dorsal fin. In most coeval ray-fins the dorsal fin has a more posterior position), usually situated opposite to the anal fin. Moreover, ptycholepiforms show a series of elongate, horizontal suborbital bones. The skull is usually relatively large. The scal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boreosomus
''Boreosomus'' (meaning: "boreal body") is an extinct genus of Triassic ray-finned fish. It was first described from the Arctic island of Spitsbergen (Svalbard, Norway), but was later also discovered in other parts of the world. ''Boreosomus'' belongs to the family Ptycholepidae (= Boreosomidae/Chungkingichthyidae). Other genera of this family are '' Acrorhabdus'' (Spitsbergen), ''Ardoreosomus'' (Nevada, United States), '' Chungkingichthys'' (China), '' Ptycholepis'' (global) and ''Yuchoulepis'' (China). Description The type species is ''Boreosomus arcticus'' (= ''Acrolepis arctica'' Woodward, 1912). A characteristic feature of this family is the dorsal fin, which inserts at the level of the pelvic fins in the middle portion of the body. Most contemporary ray-fins have their dorsal fin in a more posterior position, often opposite to the anal fin. Also typical for ptycholepids are the somewhat rectangular, horizontally arranged suborbital bones. Fossil record ''Boreosomus'' h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ardoreosomus
''Ardoreosomus'' (meaning: "tropical body") is an extinct genus of ray-finned fish. It was described from the Induan aged Candelaria Formation of Nevada, United States, which was located near the equator during the Early Triassic epoch. It contains only one species, ''A. occidentalis'' (monotypy). ''Ardoreosomus'' is a ptycholepiform, closely resembling '' Boreosomus'' and '' Ptycholepis''; however, ''Ardoreosomus'' is distinguished from other ptycholepiforms in having a more strongly angled hyomandibula and lacking an opercular process, among other features. See also * Prehistoric fish * List of prehistoric bony fish * Paleontology in Nevada Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the U.S. state of Nevada. Nevada has a rich fossil record of plants and animal life spanning the past 650 million years of time. The earliest fo ... References Prehistoric ray-finned fish genera {{Triassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma and Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic fauna Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, such as the marine reptiles (e.g. ichthyosaurs, sauropterygians, thallatosaurs), ray-finned fish and many invertebrate groups like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Fish
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include ''Haikouichthys''. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate ancient pre-jawed fish. Lampreys belong to the Cyclostomata, which includes the extant hagfish, and this group may have split early on from other agnathans. The earliest Gnathostomata, jawed vertebrates probably developed during the late Ordovician period. They are first represented in the fossil record from the Silurian by two groups of fish: the armoured fish known as Placodermi, placoderms, which evolved from the ostracoderms; and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuchoulepis
''Yuchoulepis'' is an extinct genus of prehistoric Actinopterygii, ray-finned fish. See also * Prehistoric fish * List of prehistoric bony fish References External links Bony fish in the online Sepkoski Database Ptycholepiformes {{Triassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the List of U.S. states and territories by area, 7th-most extensive, the List of U.S. states and territories by population, 32nd-most populous, and the List of U.S. states and territories by population density, 9th-least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, Nevada, Clark County, which contains the Las Vegas–Paradise, NV MSA, Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City, Nevada, Carson City. Las Vegas is the largest city in the state. Nevada is officially known as the "Silver State" because of the importance of silver to its history and economy. It is also known as the "Battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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