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Neoichthyosauria
Parvipelvia (Latin for "little pelvis" - ''parvus'' meaning "little" and ''pelvis'' meaning "pelvis") is an extinct clade of euichthyosaur ichthyosaurs that existed from the Late Triassic to the early Late Cretaceous (middle Norian to Cenomanian) of Asia, Australia, Europe, North America and South America. Named by Ryosuke Motani, in 1999, it contains the basal taxa like '' Macgowania'' and '' Hudsonelpidia''. Maisch and Matzke (2000) found in their analysis seven synapomorphies that support Parvipelvia. They also found 10 synapomorphies that support the existence of post-Triassic clade of ichthyosaurs (all parvipelvians excluding ''Macgowania'' and ''Hudsonelpidia''), for which the name Neoichthyosauria was found to be available. Parvipelvians were the only ichthyosaurs to survive the Triassic-Jurassic extinction event. Phylogeny Parvipelvia is a node-based taxon defined in 1999 as "the last common ancestor of ''Hudsonelpidia'', ''Macgowania'', ''Ichthyosaurus'' and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dearcmhara
''Dearcmhara'' (pronounced like "jark vara"; Scottish Gaelic: "marine lizard") is a genus of marine reptile from the early to mid-Jurassic period around 170 million years ago, known from fossil remains found on the island of Skye in Scotland. The type species is ''Dearcmhara shawcrossi''. Fragmentary fossil remains of the animal were discovered by an amateur fossil hunter in 1959 and were subsequently donated to a museum, but it was not until 2014 that a scientific research project determined that the fossils were of a previously unknown species. Description ''Dearcmhara'' was a basal neoichthyosaurian ichthyosaur, measuring around in length. It lived in a warm, shallow sea in what is now the north-west of Scotland. Much of Skye was underwater at the time and was joined with the rest of the UK as part of a large island between the landmasses that were later to become Europe and North America. The type species, ''Dearcmhara shawcrossi'', was discovered in an extremely incomplete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norian
The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian. Stratigraphic definitions The Norian was named after the Noric Alps in Austria. The stage was introduced into scientific literature by Austrian geologist Edmund Mojsisovics von Mojsvar in 1869. The Norian Stage begins at the base of the ammonite biozones of '' Klamathites macrolobatus'' and '' Stikinoceras kerri'', and at the base of the conodont biozones of '' Metapolygnathus communisti'' and '' Metapolygnathus primitius''. A global reference profile for the base (a GSSP) had in 2009 not yet been appointed. The top of the Norian (the base of the Rhaetian) is at the first appearance of ammonite species '' Cochloceras amoenum''. The base of the Rheatian is also close to the first appearance of conodont species '' Misikella spp.'' and '' Epigondolella mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmosaurus Icenicus
''Ophthalmosaurus'' (meaning "eye lizard" in Greek) is an ichthyosaur of the Jurassic period (165–150 million years ago). Possible remains from the Cretaceous, around 145 million years ago, are also known. It was a relatively medium-sized ichthyosaur, measuring long and weighing . Named for its extremely large eyes, it had a jaw containing many small but robust teeth. Major fossil finds of this genus have been recorded in Europe with a second species possibly being found in North America. Description ''Ophthalmosaurus'' was a medium-sized ichthyosaur, measuring long and weighing . It had a robust, streamlined body that was nearly as wide as it was tall in frontal view. Like other derived ichthyosaurs ''Ophthalmosaurus'' had a powerful tail ending in a pronounced bi-lobed caudal fluke whose lower half was formed around the caudal spine whereas the upper lobe was made up entirely from soft tissue. The limbs of ''Ophthalmosaurus'' were short and rounded with the forelimbs bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temnodontosaurus Trigonodon
''Temnodontosaurus'' (Greek for "cutting-tooth lizard"temno, meaning "to cut", odont meaning "tooth" and sauros meaning "lizard") is an extinct genus of ichthyosaur from the Early Jurassic period. They lived between 200 and 175 million years ago (Hettangian-Toarcian) in what is now Western Europe, Western Europe (England, France, Luxembourg, Germany and Belgium) and possibly Chile. It lived in the deeper areas of the open ocean.Motani R.(2000). “Rulers of the Jurassic seas”. Scientific American. 283 (6): 52-59 University of Bristol paleontologist Jeremy Martin described the genus ''Temnodontosaurus'' as "one of the most ecologically disparate genera of ichthyosaurs," although the number of valid ''Temnodontosaurus'' species has varied over the years. ''Temnodontosaurus'' was one of the largest ichthyosaurs, with the type species (''T. platyodon'') reaching up to in maximum body length. It is known for its incredibly large eyes which, at approximately in diameter, are belie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hudsonelpidia
''Hudsonelpidia'' is an extinct genus of small parvipelvian ichthyosaur known from British Columbia of Canada. Description ''Hudsonelpidia'' is known only from the holotype, a nearly complete skeleton measuring less than long. It was collected in the Jewitt Spur locality from the Pardonet Formation, dating to the middle Norian stage of the Late Triassic, about 210 million years ago. It was found on the northern shore of the Peace Reach branch of Williston Lake. ''Hudsonelpidia'' has a very stable position in many cladistic analyses. The family Hudsonelpidiidae was named by McGowan and Motani in 2003 to include this genus.McGowan C, Motani R. 2003. Ichthyopterygia. – In: Sues, H.-D. (ed.): ''Handbook of Paleoherpetology, Part 8, Verlag Dr. Friedrich Pfeil'', 175 pp., 101 figs., 19 plts; München Taxonomy ''Hudsonelpidia'' was named by Chris McGowan in 1995 and the type species In zoological nomenclature, a type species (''species typica'') is the species name with whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macgowania
''Macgowania'' is an extinct genus of parvipelvian ichthyosaur known from British Columbia of Canada. History of research ''Macgowania'' is known only from the holotype ROM 41992 ( RBCM EH 91.2.5), a partial skeleton which preserved nearly complete skull, almost complete forefin and other postcranial elements. It was collected in the Jewitt Spur locality from the Pardonet Formation, dating to the middle Norian stage of the Late Triassic, about 210 million years ago. It was found on the northern shore of the Peace Reach branch of Williston Lake. A second specimen from the same locality, ROM 41991, may be referable to this genus based on its forefin structure, but this cannot be confirmed due to its poor preservation. ''Macgowania'' has a very stable position in many cladistic analyses. The family Macgowaniidae was named by McGowan and Motani in 2003 to include this genus.McGowan C, Motani R. 2003. Ichthyopterygia. – In: Sues, H.-D. (ed.): ''Handbook of Paleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...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] |
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