Portal:Permian

Topics Culture Geography Health History Mathematics Nature People Philosophy Religion Society Technology The Permian Portal The Permian is a geologic period and system which extends from 298.9 ± 0.15 to 252.17 ± 0.06 (Million years ago). It is the last period of the Paleozoic Era, following the Carboniferous Period and preceding the Triassic Period of the Mesozoic Era. It was first introduced in 1841 by geologist Sir Roderick Murchison, and is named after the ancient kingdom of Permia. The Permian witnessed the diversification of the early amniotes into the ancestral groups of the mammals, turtles, lepidosaurs and archosaurs. The world at the time was dominated by a single supercontinent known as Pangaea, surrounded by a global ocean called Panthalassa. The extensive rainforests of the Carboniferous had disappeared, leaving behind vast regions of arid desert within the continental interior. Reptiles, who could better cope with these drier conditions, rose to dominance in lieu of their amphibian ancestors. The Permian Period (along with the Paleozoic Era) ended with the largest mass extinction in Earth's history, in which nearly 90% of marine species and 70% of terrestrial species died out. It would take well into the Triassic for life to recover from this catastrophe. (See more…) Template:/box-footer Entoprocta is a phylum of mostly sessile marine animals, ranging from 0.1 to 7 millimetres (0.0039 to 0.2756 in) long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and both the mouth and anus lie inside the "crown". Most families of entoprocts are colonial. Some species eject unfertilized ova into the water, while others keep their ova in brood chambers until they hatch, and some of these species use placenta-like organs to nourish the developing eggs. After hatching, the larvae swim for a short time and then settle on a surface. There they metamorphose, and the larval gut generally rotates by up to 180°, so that the mouth and anus face upwards. Both colonial and solitary species also reproduce by cloning – solitary species grow clones in the space between the tentacles and then release them when developed, while colonial ones produce new members from the stalks or from corridor-like stolons. Fossils of entoprocts are very rare, and the earliest specimens that have been identified with confidence date from the Late Jurassic. Most studies from 1996 onwards have regarded entoprocts as members of the Trochozoa, which also includes molluscs and annelids. However, a study in 2008 concluded that entoprocts are closely related to bryozoans. Recently, the Maotianshan Shales fossil,Cotyledion tylodes, has been reevaluated as being an ancient, sclerite-bearing entoproct. (see more...) A skeletal mount of Edaphosaurus. Paleontology or palaeontology (/ˌpeɪlɪɒnˈtɒlədʒi/, /ˌpeɪlɪənˈtɒlədʒi/ or /ˌpælɪɒnˈtɒlədʒi/, /ˌpælɪənˈtɒlədʒi/) is the scientific study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments (their paleoecology). As a "historical science" it attempts to explain causes rather than conduct experiments to observe effects. Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek: παλαιός (palaios) meaning "old, ancient," ὄν, ὀντ- (on, ont-), meaning "being, creature" and λόγος (logos), meaning "speech, thought, study". Paleontology lies on the border between biology and geology. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics and engineering. Use of all these techniques has enabled paleontologists to discover much of the evolutionary history of life, almost all the way back to when Earth became capable of supporting life, about 3,800 million years ago. As knowledge has increased, paleontology has developed specialized sub-divisions, some of which focus on different types of fossil organisms while others study ecology and environmental history, such as ancient climates. Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave fossils. (see more...) Woodton Conglomerate. Clast-supported, polymictic conglomerate in the Woodton Formation (Permian), NSW, Australia. Photo credit: Rygel, M.C. Methanosarcina barkeri fusaro. ... that the single-celled Methanosarcina (Methanosarcina barkeri fusaro pictured) may have played a significant role in both the evolution of early life and the worst extinction event in history? ... that Gerobatrachus is considered to be a missing link that supports the hypothesis offered by cladistics, that frogs and salamanders had a common ancestor? ... that Arthropleuridea is an extinct class of myriapods which includes, at over 2 meters long, the largest terrestrial arthropods that ever lived? Template:/box-header Epochs - Cisuralian - Guadalupian - Lopingian Ages - Asselian - Sakmarian - Artinskian - Kungurian - Roadian - Wordian - Capitanian -Wuchiapingian - Changhsingian Events - Hunter-Bowen orogeny - Permian–Triassic extinction event Geography - Pangaea - Panthalassa Animals - Ammonoids - Blattopterans - Dicynodonts - Dinocephalians - Fusulinids - Gorgonopsians - Lepospondyls - Pareiasaurs - Pelycosaurs - Temnospondyls - Trilobites Plants - Conifers - Cycads - Ginkgos - Seed ferns Fossil sites - Paleorrota Stratigraphic units - Red Beds of Texas and Oklahoma Researchers - Edward Drinker Cope Culture - Animal Armageddon - The Day The Earth Nearly Died - List of creatures in the Walking with... series - Walking with Monsters Template:/box-footer Template:/box-header Featured Permian articles - Amphibian Good Permian articles - Dimetrodon - Temnospondyli Template:/box-footer ▼ Permian ► Permian life Here are some tasks awaiting attention: Stubs : Permian stubs Current Permian FACs - none currently Template:/box-footer Time Earth sciences Paleontology Extinct and Endangered Species Paleozoic Cambrian Ordovician Silurian Error creating thumbnail: File missing Devonian Carboniferous Permian Mesozoic What are portals? 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