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Aristonectes
''Aristonectes'' (meaning 'best swimmer') is an extinct genus of plesiosaur from the Late Cretaceous Paso del Sapo Formation of what is now Argentina, the Quiriquina Formation of Chile and the Lopez de Bertodano Formation of Antarctica. The type species is ''Aristonectes parvidens'', first named by Cabrera in 1941. Description Analysis of a specimen from the Lopez de Bertodano Formation indicates that ''Aristonectes'' was one of the largest plesiosaurs ever to exist, with an estimated body length of and body mass of per Paul and per O'Gorman and his colleagues. Classification ''Aristonectes'' was classified variously since its original 1941 description, but a 2003 review of plesiosaurs from Patagonia conducted by Gasparini ''et al.'' (2003) found that ''Aristonectes'' was most closely related to elasmosaurid plesiosaurs like ''Elasmosaurus''. The authors also considered '' Morturneria'' a junior synonym of ''Aristonectes'' because the former's holotype has unfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristonectes NT Small
''Aristonectes'' (meaning 'best swimmer') is an extinct genus of plesiosaur from the Late Cretaceous Paso del Sapo Formation of what is now Argentina, the Quiriquina Formation of Chile and the Lopez de Bertodano Formation of Antarctica. The type species is ''Aristonectes parvidens'', first named by Cabrera in 1941. Description Analysis of a specimen from the Lopez de Bertodano Formation indicates that ''Aristonectes'' was one of the largest plesiosaurs ever to exist, with an estimated body length of and body mass of per Paul and per O'Gorman and his colleagues. Classification ''Aristonectes'' was classified variously since its original 1941 description, but a 2003 review of plesiosaurs from Patagonia conducted by Gasparini ''et al.'' (2003) found that ''Aristonectes'' was most closely related to elasmosaurid plesiosaurs like ''Elasmosaurus''. The authors also considered '' Morturneria'' a junior synonym of ''Aristonectes'' because the former's holotype has unfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristonectes Scale
''Aristonectes'' (meaning 'best swimmer') is an extinct genus of plesiosaur from the Late Cretaceous Paso del Sapo Formation of what is now Argentina, the Quiriquina Formation of Chile and the Lopez de Bertodano Formation of Antarctica. The type species is ''Aristonectes parvidens'', first named by Cabrera in 1941. Description Analysis of a specimen from the Lopez de Bertodano Formation indicates that ''Aristonectes'' was one of the largest plesiosaurs ever to exist, with an estimated body length of and body mass of per Paul and per O'Gorman and his colleagues. Classification ''Aristonectes'' was classified variously since its original 1941 description, but a 2003 review of plesiosaurs from Patagonia conducted by Gasparini ''et al.'' (2003) found that ''Aristonectes'' was most closely related to elasmosaurid plesiosaurs like ''Elasmosaurus''. The authors also considered '' Morturneria'' a junior synonym of ''Aristonectes'' because the former's holotype has unfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Plesiosaur Research
This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of plesiosaurs, an order of marine reptiles that flourished during the Mesozoic Era. The first scientifically documented plesiosaur fossils were discovered during the early 19th century by Mary Anning. Plesiosaurs were actually discovered and described before dinosaurs. They were also among the first animals to be featured in artistic reconstructions of the ancient world, and therefore among the earliest prehistoric creatures to attract the attention of the lay public. Plesiosaurs were originally thought to be a kind of primitive transitional form between marine life and terrestrial reptiles. However, now plesiosaurs are recognized as highly derived marine reptiles descended from terrestrial ancestors. Early researchers thought that plesiosaurs laid eggs like most reptiles. They commonly imagined ples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmosaurus
''Elasmosaurus'' (;) is a genus of plesiosaur that lived in North America during the Campanian stage of the Late Cretaceous period, about 80.5million years ago. The first specimen was discovered in 1867 near Fort Wallace, Kansas, US, and was sent to the American paleontologist Edward Drinker Cope, who named it ''E.platyurus'' in 1868. The generic name means "thin-plate reptile", and the specific name means "flat-tailed". Cope originally reconstructed the skeleton of ''Elasmosaurus'' with the skull at the end of the tail, an error which was made light of by the paleontologist Othniel Charles Marsh, and became part of their "Bone Wars" rivalry. Only one incomplete ''Elasmosaurus'' skeleton is definitely known, consisting of a fragmentary skull, the spine, and the pectoral and pelvic girdles, and a single species is recognized today; other species are now considered invalid or have been moved to other genera. Measuring in length and in body mass, ''Elasmosaurus'' would have ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tatenectes
''Tatenectes'' is a genus of cryptoclidid plesiosaur known from the Upper Jurassic of Wyoming. Its remains were recovered from the Redwater Shale Member of the Sundance Formation, and initially described as a new species of '' Cimoliosaurus'' by Wilbur Clinton Knight in 1900. It was reassigned to '' Tricleidus'' by Maurice G. Mehl in 1912 before being given its own genus by O'Keefe and Wahl in 2003. ''Tatenectes laramiensis'' is the type and only species of ''Tatenectes''. While the original specimen was lost, subsequent discoveries have revealed that ''Tatenectes'' was a very unusual plesiosaur. Its torso had a flattened, boxy cross-section and its gastralia (belly ribs) exhibit pachyostosis (thickening). The total length of ''Tatenectes'' has been estimated at . ''Tatenectes'' is related to '' Kimmerosaurus'', although their taxonomic placement has varied. They were once considered to be close relatives of ''Aristonectes'' in the family Cimoliasauridae or Aristonect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morturneria
''Morturneria'' is an extinct genus of plesiosaur from the Late Cretaceous of what is now Antarctica. History of research The Lopez de Bertodano Formation is located on Seymour Island, Antarctica, with exposures present in all but the northernmost third of the island. During the summers of 1981–1982, 1983–1984, and 1984–1985, paleontological expeditions recovered eight partial plesiosaur skeletons in the formation. One of these, TTU P9219, consisted of a skull and some cervical vertebrae. It was found in the upper part of the formation, informally known as the 'molluscan units', high up in a ravine. It was preserved within a tough, calcareous nodule, from which it was difficult to remove. While excavating the specimens, the dig teams faced difficulty in removing the strata above the fossils, due to the presence of permafrost. The cold temperatures also prevented the plaster from setting, so the teams used camp stoves and aluminium foil to heat it up, allowing it to har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Plesiosaur Genera
This list of plesiosaurs is a comprehensive listing of all genera that have ever been included in the order Plesiosauria, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ('' nomen dubium''), or were not formally published ('' nomen nudum''), as well as junior synonyms of more established names, and genera that are no longer considered plesiosaurs. The list currently includes 201 genera. Scope and terminology There is no official, canonical list of plesiosaur genera but one of the most thorough attempts can be found on the Plesiosauria section of Mikko Haaramo's Phylogeny Archive; also pertinent is the Plesiosaur Genera section at Adam Stuart Smith's Plesiosaur Directory.See Smith, ''Plesiosaur Genera''. Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Junior synonym: A name which describes the same taxon as a previo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quiriquina Formation
The Quiriquina Formation is a geological formation in Chile whose strata date back to the 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'', .... Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. . The glauconite, glauconitic sandstones and conglomerate (geology), conglomerates of the formation were deposited in a marine depositional environment, environment. Vertebrate paleofauna * ''Aristonectes, Aristonectes quiriquinensis'' * ''Australobaena, Australobaena chilensis'' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmosaurid
Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian to the Maastrichtian stages of the Cretaceous, and represented one of the two groups of plesiosaurs present at the end of the Cretaceous alongside Polycotylidae. Their diet mainly consisted of crustaceans and molluscs. Description The earliest elasmosaurids were mid-sized, about . In the Late Cretaceous, elasmosaurids grew as large as , such as ''Styxosaurus'', ''Albertonectes'', and '' Thalassomedon''. Their necks were the longest of all the plesiosaurs, with anywhere between 32 and 76 (''Albertonectes'') cervical vertebrae. They weighed up to several tons. Classification Early three-family classification Though Cope had originally recognized ''Elasmosaurus'' as a plesiosaur, in an 1869 paper he placed it, with ''Cimoliasaurus'' and ''Crymocetus'', in a new order of sauropterygian reptiles. He named the group Streptosaur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaiwhekea
''Kaiwhekea'' () is an extinct genus of plesiosaur from the Late Cretaceous (Maastrichtian age) of what is now New Zealand. History of discovery The type species, ''Kaiwhekea katiki'', was first described by Arthur Cruickshank and Ewan Fordyce in 2002. ''Kaiwhekea'' was approximately long and weighed in body mass. It lived around the middle Maastrichtian. The single known specimen, found in the Katiki Formation near Shag Point on the coast of Otago, is nearly complete, and is on display at the Otago Museum in Dunedin, New Zealand. Classification ''Kaiwhekea'' has been placed as an aristonectine plesiosaur close to ''Aristonectes'' (O'Keefe and Street, 2009). In 2010, ''Kaiwhekea'' was transferred to Leptocleididae, but more recent analyses do not find the same result. The following cladogram shows the placement of ''Kaiwhekea'' within Elasmosauridae following an analysis by Rodrigo A. Otero, 2016: See also * List of plesiosaur genera * Timeline of plesiosaur research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiosaur
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago. They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago. They had a worldwide oceanic distribution, and some species at least partly inhabited freshwater environments. Plesiosaurs were among the first fossil reptiles discovered. In the beginning of the nineteenth century, scientists realised how distinctive their build was and they were named as a separate order in 1835. The first plesiosaurian genus, the eponymous ''Plesiosaurus'', was named in 1821. Since then, more than a hundred valid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paso Del Sapo Formation
The Paso del Sapo Formation is a Maastrichtian geologic formation of the Cañadón Asfalto Basin in Argentina. The siltstones of the formation were deposited in a lacustrine environment. Plesiosaur remains are among the fossils that have been recovered from its strata. Fossil content * ''Aristonectes parvidens'' at .org * '' Ptychoceratodus
''Ptychoceratodus'' is an extinct genus of lungfish living from Early Triassic to Middle Jurassic. It was established by Otto Jaekel for one species (''P. runcinatus'') ...
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