Portal:Triassic

Topics Culture Geography Health History Mathematics Nature People Philosophy Religion Society Technology The Triassic Portal Mounted skeletons at the AMNH. The Triassic /traɪˈæsɪk/ is a geologic period and system that extends from about 250 to 200 Ma (252.17 ± 0.06 to 201.3 ± 0.2 million years ago). It is the first period of the Mesozoic Era, and lies between the Permian and Jurassic periods. Both the start and end of the period are marked by major extinction events. The Triassic was named in 1834 by Friedrich von Alberti, after the three distinct rock layers (tri meaning "three") that are found throughout Germany and northwestern Europe—red beds, capped by marine limestone, followed by a series of terrestrial mud- and sandstones—called the "Trias." The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it would take well into the middle of the period for life to recover its former diversity. Therapsids and archosaurs were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs, dinosaurs, first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic. The first true mammals, themselves a specialized subgroup of Therapsids also evolved during this period, as well as the first flying vertebrates, the pterosaurs, who like the dinosaurs were a specialized subgroup of archosaurs. The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, with deserts spanning much of Pangaea's interior. However, the climate shifted and became more humid as Pangaea began to drift apart. The end of the period was marked by yet another major mass extinction, wiping out many groups and allowing dinosaurs to assume dominance in the Jurassic. (see more...) Template:/box-footer The evolutionary history of life on Earth traces the processes by which living and fossil organisms have evolved since life on the planet first originated until the present day. Earth formed about 4.5 Ga (billion years ago) and life appeared on its surface within one billion years. Microbial mats of coexisting bacteria and archaea were the dominant form of life in the early Archean. The evolution of oxygenic photosynthesis, around 3.5 Ga, eventually led to the oxygenation of the atmosphere, beginning around 2.4 Ga. The earliest evidence of eukaryotes (complex cells with organelles), dates from 1.85 Ga, and while they may have been present earlier, their diversification accelerated when they started using oxygen in their metabolism. Later, around 1.7 Ga, multicellular organisms began to appear, with differentiated cells performing specialised functions. The earliest land plants date back to around 450 Ma (million years ago), although evidence suggests that algal scum formed on the land as early as 1.2 Ga. Land plants were so successful that they are thought to have contributed to the late Devonian extinction event. Invertebrate animals appear during the Vendian period, while vertebrates originated about525 Ma during the Cambrian explosion. During the Permian period, synapsids, including the ancestors of mammals, dominated the land, but the Permian–Triassic extinction event251 Ma came close to wiping out all complex life. (see more...) 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...) Reconstructed skeleton of Smok wawelski at the University of Warsaw. Photo credit: User:Panek ... that the large prehistoric amphibian Cyclotosaurus had a skull up to 70 cm long? ... that Dactylosaurus lived in the Middle Triassic period during the Anisian faunal stage of central Europe? ... that although Atopodentatus had a fearsome set of teeth, it was a filter feeder and not a predator? ...that Megazostrodon (pictured) is widely accepted as being one of the first mammals to have appeared on Earth? ...that the type specimen of Dromicosuchus had damage to its jaw and neck that may have been inflicted by the teeth of the large carnivore it was found underneath? Template:/box-header Epochs - Early Triassic - Middle Triassic - Late Triassic Stages - Induan - Olenekian - Anisian - Ladinian - Carnian - Norian - Rhaetian Events - Cambrian–Ordovician extinction event - Great Ordovician Biodiversification Event - Taconic orogeny - Late Ordovician glaciation - Alice Springs Orogeny - Ordovician–Silurian extinction event Landmasses - Baltica - Gondwana - Laurentia - Siberia Bodies of water - Iapetus Ocean - Khanty Ocean - Proto-Tethys Ocean - Rheic Ocean - Tornquist Sea - Ural Ocean Animals - Articulate brachiopods - Bryozoans - Cornulitids - Crinoids - Cystoids - Gastropods - Graptolites - Jawed fishes - Nautiloids - Ostracoderms - Rugose corals - Star fishes - Tabulate corals - Tentaculitids - Trilobites Trace fossils - Petroxestes - Trypanites Plants - Marchantiophyta Fossil sites - Beecher's Trilobite Bed - Walcott–Rust quarry Stratigraphic units - Chazy Formation - Fezouata formation - Holston Formation - Kope Formation - Potsdam Sandstone - St. Peter Sandstone Researchers - Charles Emerson Beecher - Charles Lapworth - Charles Doolittle Walcott Culture - Animal Armageddon - List of creatures in the Walking with... series - Sea Monsters Template:/box-footer Template:/box-header Featured Mesozoic articles - Bone Sharps, Cowboys, and Thunder Lizards - Bone Wars - Edward Drinker Cope - Geology of the Capitol Reef area - Geology of the Death Valley area -Geology of the Grand Canyon area - Geology of the Zion and Kolob canyons area Good Mesozoic articles - Chitinozoan - Coal ball - Dimetrodon - History of paleontology - Evolutionary history of life - Ornatifilum - Opabinia - Paleontology- Schinderhannes - Small shelly fauna - Temnospondyli - Tiktaalik - Waptia Template:/box-footer ▼ Mesozoic ► Triassic ► Jurassic ► Cretaceous ► Mesozoic life Here are some tasks awaiting attention: Stubs : Mesozoic stubs, Triassic stubs, Jurassic stubs, Cretaceous stubs Current Paleozoic FACs - none currently Template:/box-footer Time Earth sciences Paleontology Extinct and Endangered Species Paleozoic Triassic Jurassic Cretaceous Cenozoic What are portals? 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