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Paleopsephurus
''Palaeopsephurus'' is an extinct genus of paddlefish in the Acipenseriformes family Polyodontidae. At present the genus contains the single species ''Palaeopsephurus wilsoni''. The genus is known primarily from the Late Cretaceous (Maastrichtian) aged Hell Creek Formation of Montana. ''Palaeopsephurus'' is one of two extinct paddlefish genera to have been found in the North American fossil record, with the other genus and species '' Crossopholis magnicaudatus'' having been described and found in the Early Eocene Green River Formation. A third extinct genus ''Protopsephurus'' with the single species '' Protopsephurus liui'' was described from China in 1994. Only two modern paddle fish species are known, ''Polyodon spathula'' in the Mississippi River System of North America, and the extinct ''Psephurus gladius'' in the Yangtze River of China. History and classification The genus was described from three partial specimens currently residing in the collections of the University ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyodontidae
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elonglated rostrums, which are thought to enhance electroreception to detect prey. Paddlefish have been referred to as "primitive fish" because Acipenseriformes are amongst the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300 million years ago. Paddlefish are almost exclusively North American and Chinese, both extant and in the fossil record. There are six known species: four extinct species known only from fossil remains (three from western North America, one from China), one extant species, the American paddlefish (''Polyodon spathula'') which is native to the Mississippi River basin in the U.S., and the Chinese paddlefish (''Psephurus gladius''), declared extinct in 2022 following a 2019 r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psephurus Gladius
The Chinese paddlefish (''Psephurus gladius''; : literal translation: "white sturgeon"), also known as the Chinese swordfish, is an extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. With records of specimens over and possibly in length, it was one of the largest species of freshwater fish. It was the only species in the genus ''Psephurus'' and one of two recent species of paddlefish (Polyodontidae), the other being the American paddlefish (''Polyodon spathula''). It was an anadromous species, meaning that it spent part of its adult life at sea, while migrating upriver to spawn. The Chinese paddlefish was officially declared extinct in 2022, with an estimated time of extinction to be by 2005, and no later than 2010, although it had become functionally extinct by 1993. The main cause of its extinction was the construction of the Gezhouba and Three Gorges dams, causing population fragmentation and blocking the anadromous spawn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossopholis
''Crossopholis'' is an extinct bony 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. History of discovery First described by Edward Drinker Cope in 1883, the first specimen consisted of an incomplete section of the fish's body and tail. In 1886, a partial skull was recovered by Cope. A nearly complete fossil wasn't recorded until 1980. This was due, in part, to the comparative rarity of the fossil as well as the similarities to other species found within the site. Classification A member of the family Polyodontidae, ''Crossopholis'' is most closely related to the American paddlefish. ''Crossopholis'' means "fringed scales"; a reference to the thousands of tiny (less than 0.5mm) scales which covered the body of the animal. Relationships of recent and fossil paddlefish genera, after Grande ''et al.'' (2002). Paleobiology The fossils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseriformes
Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls. Description The axial skeleton of Acipenseriformes is only partially ossified, with the majority of the bones being replaced with cartilage. The notochord, usually only found in fish embryos, is unconstricted and retained throughout life. The premaxilla and maxilla bones of the skull present in other vertebrates have been lost. The infraorbital nerve is carried by a series of separate canals, rather than being within the circumorbital bones. The palatoquadrate bones of the skull possess a cartilagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museums At The University Of Michigan
The University of Michigan in Ann Arbor is home to a number of museums. Located on the university's Central Campus are University of Michigan Museum of Natural History; the University of Michigan Museum of Art; the Kelsey Museum of Archaeology; Sindecuse Museum of Dentistry of the School of Dentistry. Adjacent to the Central Campus is the Nichols Arboretum and Matthaei Botanical Gardens. Located on the university's North Campus is the Warren Robbins Gallery and Slusser Gallery of the Penny W. Stamps School of Art & Design and the Stearns Collection of Musical Instruments of the School of Music, Theatre & Dance. Central Campus University of Michigan Museum of Natural History The University of Michigan Museum of Natural History, formerly known as the Exhibit Museum of Natural History, began in the mid-19th century and expanded greatly with the donation of 60,000 specimens by Joseph Beal Steere, an UM alumnus, in the 1870s. The building also houses three research museums: the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangtze River
The Yangtze or Yangzi ( or ; ) is the longest list of rivers of Asia, river in Asia, the list of rivers by length, third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in the Tanggula Mountains (Tibetan Plateau) and flows in a generally easterly direction to the East China Sea. It is the List of rivers by discharge, seventh-largest river by discharge volume in the world. Its drainage basin comprises one-fifth of the land area of China, and is home to nearly one-third of the demographics of China, country's population. The Yangtze has played a major role in the history of China, history, culture of China, culture, and economy of China. For thousands of years, the river has been used for water, irrigation, sanitation, transportation, industry, boundary-marking, and war. The prosperous Yangtze Delta generates as much as 20% of historical GDP of China, China's GDP. The Three Gorges Dam on the Yangtze is the list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany, an isotype is a duplicate of the holotype, where holotype and isotypes are often pieces from the same individual plant or samples from the same gathering. A holotype is not necessarily "typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Michigan
, mottoeng = "Arts, Knowledge, Truth" , former_names = Catholepistemiad, or University of Michigania (1817–1821) , budget = $10.3 billion (2021) , endowment = $17 billion (2021)As of October 25, 2021. , president = Santa Ono , provost = Laurie McCauley , established = , type = Public research university , academic_affiliations = , students = 48,090 (2021) , undergrad = 31,329 (2021) , postgrad = 16,578 (2021) , administrative_staff = 18,986 (2014) , faculty = 6,771 (2014) , city = Ann Arbor , state = Michigan , country = United States , coor = , campus = Midsize City, Total: , including arboretum , colors = Maize & Blue , nickname = Wolverines , sporti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ann Arbor, Michigan
Ann Arbor is a city in the U.S. state of Michigan and the county seat of Washtenaw County, Michigan, Washtenaw County. The 2020 United States census, 2020 census recorded its population to be 123,851. It is the principal city of the Ann Arbor List of metropolitan statistical areas, Metropolitan Statistical Area, which encompasses all of Washtenaw County. Ann Arbor is also included in the Metro Detroit, Greater Detroit Combined statistical area, Combined Statistical Area and the Great Lakes megalopolis, the most populated and largest Megaregions of the United States, megalopolis in North America. Ann Arbor is home to the University of Michigan. The university significantly shapes Ann Arbor's economy as it employs about 30,000 workers, including about 12,000 in the University of Michigan Health System, medical center. The city's economy is also centered on high technology, with several companies drawn to the area by the university's research and development infrastructure. Ann A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyodon Spathula
The American paddlefish (''Polyodon spathula,'' also known as a Mississippi paddlefish, spoon-billed cat, or spoonbill) is a species of ray-finned fish. It is the only living species of paddlefish (Polyodontidae). This family is most closely related to the sturgeons; together they make up the order Acipenseriformes, which are one of the most primitive living groups of ray-finned fish. Fossil records of other paddlefish species date back 125 million years to the Early Cretaceous, with records of ''Polyodon'' extending back 65 million years to the early Paleocene. The American paddlefish is a smooth-skinned freshwater fish with an almost entirely cartilaginous skeleton and a paddle-shaped rostrum (snout), which extends nearly one-third its body length. It has been referred to as a freshwater shark because of its heterocercal tail or caudal fin resembling that of sharks, though it is not closely related. The American paddlefish is a highly derived fish because it has evolved speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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