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Ischyrotherium
''Ischyrotherium'' is an extinct genus named by Joseph Leidy in 1856 for fossils from the lignite deposits in Nebraska. Originally considered an herbivorous cetacean, Leidy then reassigned it to Sirenia as a relative of manatees, before Edward Drinker Cope reclassified it as a non-mammalian, suggesting the new name ''Ischyrosaurus'' to better identify its reptilian origins, as he considered it a sauropterygian. ''Ischyrotherium'' was found alongside material from the hadrosaur ''Thespesius'' and turtles ''Compsemys ''Compsemys '' is an extinct genus of prehistoric turtles from the Late Cretaceous and Paleocene of North America and possibly Europe. The type species ''C. victa'', first described by Joseph Leidy from the Hell Creek Formation in Montana in 1856 ...'' and '' Emys'', and the fish '' Mylognathus''. The name ''Ischyrosaurus'' was also used by John Whitaker Hulke for the sauropod now known as '' Ornithopsis manseli'', as he was unaware it was preoccupied by Cope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithopsis Manseli
''Ornithopsis'' (meaning "bird-likeness") was a medium-sized Early Cretaceous sauropod dinosaur, from England. The type species, which is the only species seen as valid today, is ''O. hulkei''. History of discovery Gideon Algernon Mantell described many fossils that had been previously collected from the Tilgate Forest of the Early Cretaceous Wealden Formation in his 1833 paper on the geology of southeast England, including a bone he considered to be the of '' Iguanodon'', otherwise only known definitively from teeth that had been found in the area since 1822. The bone was redescribed by Richard Owen in 1854, who reaffirmed its referral as a quadrate of ''Iguanodon'', but also suggested it could be the same bone of ''Streptospondylus'' or '' Cetiosaurus'' as it was not directly associated with the characteristic teeth of ''Iguanodon''. This specimen is stored as British Museum of Natural History R2239, having been purchased from Mantell in 1838. BMNH R28632, a similar bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Reptiles Of North America
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Whitaker Hulke
John Whitaker Hulke FRCS FRS FGS (6 November 1830 – 19 February 1895) was a British surgeon, geologist and fossil collector. He was the son of a physician in Deal, who became a Huxleyite despite being deeply religious. Hulke became Huxley's colleague at the Royal College of Surgeons. He was a long-time collector from the Wealden cliffs of the Isle of Wight, and his work on vertebrate palaeontology included studies of ''Iguanodon'' and ''Hypsilophodon'' from the Wealden (Lower Cretaceous). He became president of the Geological Society (1882–84); and was awarded Wollaston Medal in 1888. He was president of the Pathological Society of London in 1883, and president of the Royal College of Surgeons from 1893 until his death. Life Hulke was born in Deal, Kent, the son of a general practitioner. He was educated partly at a boarding-school in England, partly at the Moravian College at Neuwied (1843–1845), where he gained an intimate knowledge of German and an interest in geolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emys
''Emys'' is a small genus of turtles in the family Emydidae. The genus (''sensu lato'') is endemic to Europe and North America. Species The following two species may be assigned to the genus ''Emys'' (''sensu lato''). ''Nota bene'': A binomial authority in parentheses indicates that the species was originally described in a genus other than ''Emys''. Taxonomy The eastern North American species, ''E. blandingii'', is usually separated into its own genus, ''Emydoidea''. Similarly, the western North American species, ''E. marmorata'' and ''E. pallida'', were recently moved to their own genus, ''Actinemys ''Actinemys'' is a small genus of turtles in the family Emydidae."''Actinemys'' ". The Reptile Database. www.reptile-database.or The genus is Endemism, endemic to the west coast of North America. The genus contains two species. Species The fol ...''. References ;Bibliography * * Further reading * Duméril AMC (1805). ''Zoologie analytique, ou méthode naturelle de clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compsemys
''Compsemys '' is an extinct genus of prehistoric turtles from the Late Cretaceous and Paleocene of North America and possibly Europe. The type species ''C. victa'', first described by Joseph Leidy from the Hell Creek Formation in Montana in 1856, and another probable species ''C. russelli'' (originally placed in the separate genus '' Berruchelus''), described in 2012, from Paleocene deposits in France''.'' Its affinites have long been uncertain, but it has recently been considered to be the most basal member of Paracryptodira, despite the clade first appearing in the Late Jurassic, and is sometimes included in its own family, Compsemydidae. A revision in 2020 found Compsemydidae to be more expansive, also containing '' Riodevemys'' and '' Selenemys'' from the Late Jurassic of Europe, and '' Peltochelys'' from the Early Cretaceous of Europe. ''Compsemys'' was a moderately sized turtle, up to long, with a carapace covered with raised, flattened tubercles, which are not seen in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thespesius
''Thespesius'' (meaning "wondrous one") is a dubious genus of hadrosaurid dinosaur from the late Maastrichtian-age Upper Cretaceous Lance Formation of South Dakota. History In 1855 geologist Ferdinand Vandeveer Hayden sent a number of fossils to paleontologist Joseph Leidy in Philadelphia. Hayden had collected them from the surface of a rock formation then known as the Great Lignite Formation (now recognized as part of the Lance Formation) in the Nebraska Territory, near the Grand River (present-day South Dakota). Among them were two caudal vertebrae and a phalanx. In 1856 Leidy named the type species ''Thespesius occidentalis'' for these three bones.Leidy, J. (1856). "Notice of extinct Vertebrata, discovered by F. V. Hayden during the expedition to the Sioux country under the command of Lieut. G.K. Warren." ''Proceedings of the Academy of Natural Science Philadelphia'', 8(December 30): 311-312. The generic name is derived from Greek θεσπεσιος, ''thespesios'', "wondro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Leidy
Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist. Leidy was professor of anatomy at the University of Pennsylvania, later was a professor of natural history at Swarthmore College and the director of scientific and educational programs at the Wagner Free Institute of Science. His book ''Extinct Fauna of Dakota and Nebraska'' (1869) contained many species not previously described and many previously unknown on the North American continent. At the time, scientific investigation was largely the province of wealthy amateurs. The Leidy Glacier in northwest Greenland was named by Robert Peary after him. Early life and family Joseph Leidy was born on September 9, 1823, to an established Philadelphia family of Pennsylvania Germans. His father, Philip, was a hatter; his mother, Catharine, died during childbirth when he was young. His father then married his wife's first cousin, Christiana Mellick. Leidy also ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosaur
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, South America and Antarctica. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex structures known as dental batteries, which acted as effective g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
