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Abyssosaurus
''Abyssosaurus'' is an extinct genus of cryptoclidid plesiosaur known from the Early Cretaceous of Chuvash Republic, western Russia. It possessed a shortened skull, and it has been suggested that it primarily inhabited the bathyal zone. Discovery ''Abyssosaurus'' is known only from the holotype specimen, Museum of Chuvash Natural Historical Society (MChEIO) no. PM/1, a partial postcranial skeleton. The holotype was collected in Poretskii District of Chuvashia, near Mishukovo, dating to the late Hauterivian faunal stage of the Early Cretaceous, about 133-130 million years ago. The specimen was initially thought to occupy an intermediate position between the Late Jurassic ''Tatenectes'' and '' Kimmerosaurus'' and the Late Cretaceous ''Aristonectes'' and ''Kaiwhekea''. Berezin (2011) considered ''Abyssosaurus'' to represent the first reliable record of Aristonectidae in Russia. A large phylogenetic analysis performed by Roger Benson and Patrick Druckenmiller found it to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2011 In Paleontology
Protozoa New taxa Plants Ferns and fern allies Gymnosperms Gymnosperm research *An amplified whole plant reconstruction of the Ypresian Princeton chert pine '' Pinus arnoldii'', expanding the diagnosis to include ''P. similkameenensis'' (Miller, 1973 Events January * January 1 - The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. * January 15 – Vietnam War: Citing progress in peace negotiations, U.S. ...) foliage and wood plus unnamed pollens cones found in attachment to the ''P. arnoldii'' ovulate cones is published by Klymiuk, Stockey, & Rothwell. Angiosperms Nematoda Lobopods Vetulicolians Molluscs Arthropods Fishes Amphibians Newly named lepospondyls Newly named temnospondyls Newly named lissamphibians Basal reptiles Newly named captorhinids Newly named basal diapsids Newly named ichthyosaurs Lepidosauromorphs Newly named saurosphargids New ... [...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] |
Cryptoclidids
Cryptoclididae is a family of medium-sized plesiosaurs that existed from the Middle Jurassic to the Early Cretaceous. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and crustaceans. The earliest members of the family appeared during the early Bajocian, and they represented the dominant group of long-necked plesiosaurs during the latter half of the Jurassic. Classification In 2010, two supposed late Cretaceous members of the group were reclassified as other kinds of plesiosauroids. ''Kaiwhekea'' was reclassified to Leptocleididae, and ''Aristonectes'' was transferred to Elasmosauridae. Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... based on Ketchum and Benson (2010): References External ... [...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] |
Cryptoclidid
Cryptoclididae is a family of medium-sized plesiosaurs that existed from the Middle Jurassic to the Early Cretaceous. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and crustaceans. The earliest members of the family appeared during the early Bajocian, and they represented the dominant group of long-necked plesiosaurs during the latter half of the Jurassic. Classification In 2010, two supposed late Cretaceous members of the group were reclassified as other kinds of plesiosauroids. ''Kaiwhekea'' was reclassified to Leptocleididae, and ''Aristonectes'' was transferred to Elasmosauridae. Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... based on Ketchum and Benson (2010): References External ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristonectidae
The Aristonectidae is a taxonomic family of poorly known plesiosaurs from the Jurassic and Cretaceous periods. They are closely related to polycotylid plesiosaurs. The family is made up of ''Tatenectes'', ''Kimmerosaurus'', ''Aristonectes'', and ''Kaiwhekea''. This group was formerly known as the Cimoliasauridae, but since ''Cimoliasaurus'' is indeterminate and quite possibly elasmosaurid, this replacement name was erected. ''Tatenectes'' and ''Kimmerosaurus'' represent an earlier Oxfordian Jurassic radiation from Laurasia, while ''Aristonectes'' and ''Kaiwhekea'' represent a later Cretaceous radiation from Gondwana. Appearance Aristonectidae were characterized by a relatively larger head and shorter neck than the Plesiosauridae and Elasmosauridae. Teeth resemble those of the Plesiosauridae. The group is known only from scanty and fragmentary remains. The formal diagnosis of the clade A clade (), also known as a monophyletic group or natural group, is a group of organis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimmerosaurus
''Kimmerosaurus'' ("lizard from Kimmeridge") is an extinct genus of plesiosaur from the family Cryptoclididae. ''Kimmerosaurus'' is most closely related to ''Tatenectes''. Discovery There are very few fossil remains of ''Kimmerosaurus'' known. In fact, nothing has been found to show what ''Kimmerosaurus'' may have looked like below the neck, although the atlas and the axis are similar to those of the plesiosaur ''Colymbosaurus''. It is this lack of any post-cranial fossils, and the bone similarities that has led to the belief that ''Kimmerosaurus'' fossils could be the missing head of ''Colymbosaurus'', a similar plesiosaur with no known skull fossils. The first part of the genus name of ''Kimmerosaurus'' comes from the location of the first ''Kimmerosaurus'' fossils, Kimmeridge Clay deposits of Dorset, England (these deposits are also the root word for the Kimmeridgian stage of the Jurassic period). The second part comes from the Greek word ('), "lizard". Description As ''K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger Benson
Roger is a given name, usually masculine, and a surname. The given name is derived from the Old French personal names ' and '. These names are of Germanic languages, Germanic origin, derived from the elements ', ''χrōþi'' ("fame", "renown", "honour") and ', ' ("spear", "lance") (Hrōþigēraz). The name was introduced into England by the Normans. In Normandy, the Franks, Frankish name had been reinforced by the Old Norse cognate '. The name introduced into England replaced the Old English cognate '. ''Roger'' became a very common given name during the Middle Ages. A variant form of the given name ''Roger'' that is closer to the name's origin is ''Rodger''. Slang and other uses Roger is also a short version of the term "Jolly Roger", which refers to a black flag with a white skull and crossbones, formerly used by piracy, sea pirates since as early as 1723. From up to , Roger was slang for the word "penis". In ''Under Milk Wood'', Dylan Thomas writes "jolly, rodgered" sugges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
