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Guizhouichthyosaurus
''Guizhouichthyosaurus'' is an extinct genus of ichthyosaur which is known primarily from the Xiaowa Formation of the lower Carnian stage of the Late Triassic in southwest China. The type species of this genus is ''Guizhouichthyosaurus tangae'', of which multiple skeletons are known. It has been reassigned as a species of the genus '' Shastasaurus'' in the past, though it has since been considered distinct. The ichthyosaurs ''Cymbospondylus asiaticus'', named in 2002, and ''Panjiangsaurus epicharis'', named in 2003, are junior synonyms of ''G. tangae''. The genus is also known from the Ladinian-aged Middle Triassic Zhuganpo Formation; additionally, the species ''"Callawayia" wollongangense'' may belong to ''Guizhouichthyosaurus''. ''Guizhouichthyosaurus'' is a large ichthyosaur, typically measuring approximately long with some specimens exceeding . The snout is long and powerful, and there is a low sagittal crest on the rear part of its skull. The tail is bent downwards nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guizhouichthyosaurus XNGM-WS-50-R4 Skull
''Guizhouichthyosaurus'' is an extinct genus of ichthyosaur which is known primarily from the Xiaowa Formation of the lower Carnian stage of the Late Triassic in southwest China. The type species of this genus is ''Guizhouichthyosaurus tangae'', of which multiple skeletons are known. It has been reassigned as a species of the genus ''Shastasaurus'' in the past, though it has since been considered distinct. The ichthyosaurs ''Cymbospondylus asiaticus'', named in 2002, and ''Panjiangsaurus epicharis'', named in 2003, are junior synonyms of ''G. tangae''. The genus is also known from the Ladinian-aged Middle Triassic Zhuganpo Formation; additionally, the species ''"Callawayia" wollongangense'' may belong to ''Guizhouichthyosaurus''. ''Guizhouichthyosaurus'' is a large ichthyosaur, typically measuring approximately long with some specimens exceeding . The snout is long and powerful, and there is a low sagittal crest on the rear part of its skull. The tail is bent downwards near its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastasaurus
''Shastasaurus'' ("Mount Shasta lizard") is a very large extinct genus of ichthyosaur from the middle and late Triassic, and is the largest known marine reptile.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specimens have been found in the United States, Canada, and China. Description left, Size of '' Shonisaurus popularis'' (green) and ''S. sikanniensis'' (red), a possible species of ''Shastasaurus'', compared with a human ''Shastasaurus'' lived during the late Triassic period. The type species ''Shastasaurus pacificus'' is known from California. ''S. pacificus'' was a medium-sized ichthyosaur, measuring over in length and weighing . A second possible species of ''Shastasaurus'', ''S. sikanniensis'', is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago). If ''S.sikanniensis'' belongs to ''Shastasaurus'', it would be the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhuganpo Formation
The Zhuganpo Formation is a Triassic geologic unit found in southern China. It has historically been known as the Zhuganpo Member of the Falang Formation. A diverse fossil assemblage known as the Xingyi biota or Xingyi Fauna can be found in the upper part of the Zhuganpo Formation. Fossils of the Xingyi biota include articulated skeletons of marine reptiles, abundant fish, and a plentiful assortment of invertebrates indicating a Ladinian to Carnian age for the sediments of the formation. Paleobiota Invertebrates * Ammonites: '' Clionitites'' sp., '' Detoniceras'' sp., '' Haoceras xingyiense'', '' Parasturia'' sp., '' Protrachyceras'' sp., '' Ptychites'' sp., '' Sinomeginoceras'' (''S. wangi, S. xingyiense''), '' Trachyceras'' sp., '' Xenoprotrachyceras'' cf. ''primum'', '' Yangites densicostatus'', * Bivalves: '' Daonella'' sp. * Conodonts: '' Gladigondolella malayensis'', ''Metapolygnathus'' / '' Paragondolella'' / '' Quadralella'' (''Q.'' aff''. acuminatus, P. foliata, P. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiaowa Formation
The Xiaowa Formation is a Carnian-age geological formation found in southern China. It is a sequence of limestone and marls from the Carnian stage of the Triassic. Its lower section was previously known as the Wayao Formation or Wayao Member of the Falang Formation (a nomenclature still used by some authors). In 2002, the Wayao Member was renamed and raised to the Xiaowa Formation to prevent confusion with an Eocene unit of the same name. Crinoids and marine reptiles are abundant in the Xiaowa Formation, forming a lagerstätte known as the Guanling biota. Ammonoids and conodonts found in the formation constrain its age to the early Carnian. Reptiles of the Guanling biota include ichthyosaurs, thalattosaurs, placodonts, and ''Odontochelys'' (an early relative of turtles). Sedimentary events within this formation have been tied to the Carnian Pluvial Event. Geology The Xiaowa Formation has three members. The lower member is relatively thin but is also very fossiliferous. It begins w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaurs
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymbospondylus
''Cymbospondylus'' (a Greek word meaning "boat vertebrae") was a basal early ichthyosaur that lived between the early and middle Triassic period (249-237 million years ago). Previously, the genus was classified as a shastasaurid, but more recent work finds it to be more basal.Motani, R. 1999: Phylogeny of the Ichthyopterygia. Journal of Vertebrate Paleontology. 19 (3): 473 – 496 ''Cymbospondylus'' was a cosmopolitan genus found in Nevada, Europe ( Switzerland, Germanic Basin) and Spitsbergen. History ''Cymbospondylus'' was described from Nevada by Joseph Leidy in 1868 on the basis of several fragmentary vertebrae which he assigned to two different species: ''C. piscosus'' (the type species) and ''C. petrinus''. The University of California, under the direction of John Campbell Merriam and funded by Annie Alexander, conducted extensive fieldwork in the region in the late nineteenth and early twentieth century, following the description of ''Cymbospondylus'', recovering addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callawayia
''Callawayia'' is an extinct genus of ichthyosaur. It contains the species ''Callawayia neoscapularis''.Sander, P.M., Chen X., Cheng L. and Wang X. (2011).Short-Snouted Toothless Ichthyosaur from China Suggests Late Triassic Diversification of Suction Feeding Ichthyosaurs. ''PLoS ONE 6(5)'': e19480. History of research In 1994, Christopher McGowan reviewed the taxonomy of '' Shastasaurus''. In this publication, he named a new species of ''Shastasaurus'', ''S. neoscapularis'', based on ROM (Royal Ontario Museum) 41993, a partial skeleton discovered on the shore of Williston Lake in Pink Mountain, British Columbia, Canada in 1987. The specimen was excavated from "Flipper Quarry" in 1988. The name of this species refers to the closer resemblance of its scapulae (shoulder blades) to Jurassic ichthyosaurs than those of other Triassic ichthyosaurs. In 2000, Michael Maisch published a study on the skull anatomy of ''Shastasaurus'', and also revised the genus again. He noted that ''S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaur
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosaur
Thalattosauria (Attic Greek, Greek for "sea lizards") is an extinct Order (biology), order of prehistoric marine reptiles that lived in the middle to late Triassic period. Thalattosaurs were diverse in size and shape, and are divided into two superfamilies: Askeptosauroidea and Thalattosauroidea. Askeptosauroids were endemic to the Tethys Ocean, their fossils have been found in Europe and China, and they were likely semiaquatic fish eaters with straight snouts and decent terrestrial abilities. Thalattosauroids were more specialized for aquatic life and most had unusual downturned snouts and crushing dentition. Thalattosauroids lived along the coasts of both Panthalassa and the Tethys Ocean, and were most diverse in China and western North America. The largest species of thalattosaurs grew to over 4 meters (13 feet) in length, including a long, flattened tail utilized in underwater propulsion. Although thalattosaurs bore a superficial resemblance to lizards, their exact relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrolith
A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In other species the rocks are ingested and pass through the digestive system and are frequently replaced. The grain size depends upon the size of the animal and the gastrolith's role in digestion. Other species use gastroliths as ballast.Rondeau, et aLarval Anurans Adjust Buoyancy in Response to Substrate IngestionCopeia: February 2005, Vol. 2005, No. 1, pp. 188-195. Particles ranging in size from sand to cobble have been documented. Etymology Gastrolith comes from the Greek γαστήρ (''gastēr''), meaning "stomach", and λίθος (''lithos''), meaning "stone". Occurrence Among living vertebrates, gastroliths are common among crocodiles, alligators, herbivorous birds, seals and sea lions. Domestic fowl require access to ''grit''. Stone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, '' Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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