User:Abyssal/Portal:Ediacaran

The Ediacaran Portal Introduction Selected article on the Ediacaran world and its legacies Artist's reconstruction of Waptia fieldensis. 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...) Selected article on the Ediacaran in human science, culture and economics Illustration of trilobite fossils by Joachim Barrande. The history of paleontology traces the history of the effort to study the fossil record left behind by ancient life forms. Although fossils had been studied by scholars since ancient times, the nature of fossils and their relationship to life in the past became better understood during the 17th and 18th centuries. At the end of the 18th century the work of Georges Cuvier ended a long running debate about the reality of extinction and led to the emergence of paleontology as a scientific discipline. The first half of the 19th century saw paleontological activity become increasingly well organized. This contributed to a rapid increase in knowledge about the history of life on Earth, and progress towards definition of the geologic time scale. As knowledge of life's history continued to improve, it became increasingly obvious that there had been some kind of successive order to the development of life. After Charles Darwin published Origin of Species in 1859, much of the focus of paleontology shifted to understanding evolutionary paths. The last half of the 19th century saw a tremendous expansion in paleontological activity, especially in North America. The trend continued in the 20th century with additional regions of the Earth being opened to systematic fossil collection, as demonstrated by a series of important discoveries in China near the end of the 20th century. There was also a renewed interest in the Cambrian explosion that saw the development of the body plans of most animal phyla. (see more...) Selected image Agnostus pisiformis (Linnaeus, 1757) as depicted in the 47th plate of Ernst Haeckel's Kunstformen der Natur.. Photo credit: User:Micha L. Rieser Did you know? Spriggina flounensi ...that the enigmatic Ediacaran biota (fossil pictured) have been classified into every major group of lifeforms, including their own kingdom? ... that fossils of Yelovichnus were initially believed to be the feeding trails of other organisms? ... that the last common ancestor of bilaterian animals has been reconstructed as a tiny worm with a combined mouth and anus? ... that Andiva (fossil pictured), an enigmatic animal that lived 555 millions of years ago, perhaps had a convex carapace? Geochronology Series - Terreneuvian - Cambrian Series 2 - Cambrian Series 3 - Furongian Epochs - Early Cambrian - Middle Cambrian - Late Cambrian Stages - Fortunian - Cambrian Stage 2 - Cambrian Stage 3 - Cambrian Stage 4 - Cambrian Stage 5 - Drumian - Guzhangian -Paibian - Jiangshanian - Cambrian Stage 10 Events - Cambrian Explosion - Cambrian substrate revolution - End-Botomian mass extinction - Cambrian–Ordovician extinction event Geography - Pannotia - Baltica - Gondwanaland - Laurentia - Siberia Animals - Archaeocyathans - Trilobites Trace fossils - Climactichnites - Protichnites Plants - Dalyia - Margaretia Fossil sites - Walcott Quarry Stratigraphic units - Burgess Shale - Maotianshan Shales Researchers - Stephen Jay Gould - Simon Conway Morris - Charles Doolittle Walcott Culture - Wonderful Life (book) Quality Content Featured Cambrian articles - None Good Cambrian articles - Fossils of the Burgess Shale - Opabinia - Small shelly fauna - Stephen Jay Gould - Waptia Subcategories Ediacaran Ediacaran Africa Ediacaran Asia Ediacaran Europe Ediacaran North America Ediacaran South America Ediacaran events Ediacaran geology Ediacaran life Ediacaran paleogeography Placozoa Vendobionta Things you can do Here are some tasks awaiting attention: Stubs : Cambrian stubs Current Cambrian FACs - none currently Related content Time Earth sciences Paleontology Extinct and Endangered Species Paleozoic Cambrian Ordovician Silurian Devonian Carboniferous Permian Associated Wikimedia The following Wikimedia Foundation sister projects provide more on this subject: Commons Free media repository Wikibooks Free textbooks and manuals Wikidata Free knowledge base Wikinews Free-content news Wikiquote Collection of quotations Wikisource Free-content library Wikiversity Free learning tools Wiktionary Dictionary and thesaurus ¤ 01 Category:Geologic time portals