The Triassic is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago, to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished. Therapsids and archosaurs were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs, called dinosaurs, first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic Period; the first true mammals, themselves a specialized subgroup of therapsids evolved during this period, as well as the first flying vertebrates, the pterosaurs, like the dinosaurs, were a specialized subgroup of archosaurs. The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to rift into two separate landmasses, Laurasia to the north and Gondwana to the south.
The global climate during the Triassic was hot and dry, with deserts spanning much of Pangaea's interior. However, the climate became more humid as Pangaea began to drift apart; the end of the period was marked by yet another major mass extinction, the Triassic–Jurassic extinction event, that wiped out many groups and allowed dinosaurs to assume dominance in the Jurassic. The Triassic was named in 1834 by Friedrich von Alberti, after the three distinct rock layers 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 is separated into Early and Late Triassic Epochs, the corresponding rocks are referred to as Lower, Middle, or Upper Triassic. The faunal stages from the youngest to oldest are: During the Triassic all the Earth's land mass was concentrated into a single supercontinent centered more or less on the equator and spanning from pole to pole, called Pangaea.
From the east, along the equator, the Tethys sea penetrated Pangaea, causing the Paleo-Tethys Ocean to be closed. In the mid-Triassic a similar sea penetrated along the equator from the west; the remaining shores were surrounded by the world-ocean known as Panthalassa. All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates; the supercontinent Pangaea was rifting during the Triassic—especially late in that period—but had not yet separated. The first nonmarine sediments in the rift that marks the initial break-up of Pangaea, which separated New Jersey from Morocco, are of Late Triassic age. S. these thick sediments comprise the Newark Group. Because a super-continental mass has less shoreline compared to one broken up, Triassic marine deposits are globally rare, despite their prominence in Western Europe, where the Triassic was first studied. In North America, for example, marine deposits are limited to a few exposures in the west, thus Triassic stratigraphy is based on organisms that lived in lagoons and hypersaline environments, such as Estheria crustaceans.
At the beginning of the Mesozoic Era, Africa was joined with Earth's other continents in Pangaea. Africa shared the supercontinent's uniform fauna, dominated by theropods and primitive ornithischians by the close of the Triassic period. Late Triassic fossils are more common in the south than north; the time boundary separating the Permian and Triassic marks the advent of an extinction event with global impact, although African strata from this time period have not been studied. During the Triassic peneplains are thought to have formed in what is now southern Sweden. Remnants of this peneplain can be traced as a tilted summit accordance in the Swedish West Coast. In northern Norway Triassic peneplains may have been buried in sediments to be re-exposed as coastal plains called strandflats. Dating of illite clay from a strandflat of Bømlo, southern Norway, have shown that landscape there became weathered in Late Triassic times with the landscape also being shaped during that time. At Paleorrota geopark, located in Rio Grande do Sul, the Santa Maria Formation and Caturrita Formations are exposed.
In these formations, one of the earliest dinosaurs, Staurikosaurus, as well as the mammal ancestors Brasilitherium and Brasilodon have been discovered. The Triassic continental interior climate was hot and dry, so that typical deposits are red bed sandstones and evaporites. There is no evidence of glaciation near either pole. Pangaea's large size limited the moderating effect of the global ocean; the strong contrast between the Pangea supercontinent and the global ocean triggered intense cross-equatorial monsoons. The Triassic may have been a dry period, but evidence exists that it was punctuated by several episodes of increased rainfall in tropical and subtropical latitudes of the Tethys Sea and its surrounding land. Sediments and fossils suggestive of a more humid climate are known from the Anisian to Ladinian of the Tethysian domain, from the Carnian and Rhaetian of a larger area that includes the Boreal domain, the North
Wikispecies is a wiki-based online project supported by the Wikimedia Foundation. Its aim is to create a comprehensive free content catalogue of all species. Jimmy Wales stated that editors are not required to fax in their degrees, but that submissions will have to pass muster with a technical audience. Wikispecies is available under the GNU Free Documentation License and CC BY-SA 3.0. Started in September 2004, with biologists across the world invited to contribute, the project had grown a framework encompassing the Linnaean taxonomy with links to Wikipedia articles on individual species by April 2005. Benedikt Mandl co-ordinated the efforts of several people who are interested in getting involved with the project and contacted potential supporters in early summer 2004. Databases were evaluated and the administrators contacted, some of them have agreed on providing their data for Wikispecies. Mandl defined two major tasks: Figure out how the contents of the data base would need to be presented—by asking experts, potential non-professional users and comparing that with existing databases Figure out how to do the software, which hardware is required and how to cover the costs—by asking experts, looking for fellow volunteers and potential sponsorsAdvantages and disadvantages were discussed by the wikimedia-I mailing list.
The board of directors of the Wikimedia Foundation voted by 4 to 0 in favor of the establishment of a Wikispecies. The project is hosted at species.wikimedia.org. It was merged to a sister project of Wikimedia Foundation on September 14, 2004. On October 10, 2006, the project exceeded 75,000 articles. On May 20, 2007, the project exceeded 100,000 articles with a total of 5,495 registered users. On September 8, 2008, the project exceeded 150,000 articles with a total of 9,224 registered users. On October 23, 2011, the project reached 300,000 articles. On June 16, 2014, the project reached 400,000 articles. On January 7, 2017, the project reached 500,000 articles. On October 30, 2018, the project reached 600,000 articles, a total of 1.12 million pages. Wikispecies comprises taxon pages, additionally pages about synonyms, taxon authorities, taxonomical publications, institutions or repositories holding type specimen. Wikispecies asks users to use images from Wikimedia Commons. Wikispecies does not allow the use of content.
All Species Foundation Catalogue of Life Encyclopedia of Life Tree of Life Web Project List of online encyclopedias The Plant List Wikispecies, The free species directory that anyone can edit Species Community Portal The Wikispecies Charter, written by Wales
The Rhizaria are a species-rich supergroup of unicellular eukaryotes. A multicellular form has been described; this supergroup was proposed by Cavalier-Smith in 2002. Being described from rDNA sequences, they vary in form, having no clear morphological distinctive characters, but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. Many produce shells or skeletons, which may be quite complex in structure, these make up the vast majority of protozoan fossils. Nearly all have mitochondria with tubular cristae; the three main groups of Rhizaria are: Cercozoa – various amoebae and flagellates with filose pseudopods and common in soil Foraminifera – amoeboids with reticulose pseudopods, common as marine benthos Radiolaria – amoeboids with axopods, common as marine planktonA few other groups may be included in the Cercozoa, but on some trees appear closer to the Foraminifera. These are the Phytomyxea and Ascetosporea, parasites of plants and animals and the peculiar amoeba Gromia.
The different groups of Rhizaria are considered close relatives based on genetic similarities, have been regarded as an extension of the Cercozoa. The name Rhizaria for the expanded group was introduced by Cavalier-Smith in 2002, who included the centrohelids and Apusozoa. Another order that appears to belong to this taxon is the Mikrocytida; these are parasites of oysters. Rhizaria are part of the Diaphoretickes clade along with Archaeplastida, Cryptista and Halvaria. Many rhizarians were considered animals because of their motility and heterotrophy. However, when a simple animal-plant dichotomy was superseded by a recognition of additional kingdoms, taxonomists placed rhizarians in the kingdom Protista; when scientists began examining the evolutionary relationships among eukaryotes using molecular data, it became clear that the kingdom Protista was paraphyletic. Rhizaria appear to share a common ancestor with Stramenopiles and Alveolates forming part of the SAR super assemblage. Rhizaria has been supported by molecular phylogenetic studies as a monophyletic group.
Biosynthesis of 24-isopropyl cholestane precursors in various rhizaria suggests a relevant ecological role during the Ediacaran. Phylogeny based on al.. 2009, Howe et al. 2011, Silar 2016. In 2019, the Cercozoa were recognized as sister of the Retaria. Molecular Phylogeny of Amoeboid Protists - Tree of Rhizaria Tree of Life Eukaryotes
A nummulite is a large lenticular fossil, characterized by its numerous coils, subdivided by septa into chambers. They are the shells of the fossil and present-day marine protozoan Nummulites, a type of foraminiferan. Nummulites vary in diameter from 1.3 cm to 5 cm and are common in Eocene to Miocene marine rocks around southwest Asia and the Mediterranean. Fossils up to six inches wide are found in the Middle Eocene rocks of Turkey, they are valuable as index fossils. The ancient Egyptians used nummulite shells as coins and the pyramids were constructed using limestone that contained nummulites, it is not surprising that the name "Nummulites" is a diminutive form of the Latin nummulus meaning "little coin", a reference to their shape. In 1913, naturalist Randolph Kirkpatrick published a book, The Nummulosphere: an account of the Organic Origin of so-called Igneous Rocks and Abyssal Red Clays, proposing the unconventional theory that all rocks had been produced through the accumulation of forams such as Nummulites.
Http://paleopolis.rediris.es/cg/CG2006_M02/index.html Aigner, Thomas. "Biofabrics as Dynamic Indicators in Nummulite Accumulations". Journal of Sedimentary Research. 55: 131–134. Doi:10.1306/212F8634-2B24-11D7-8648000102C1865D. Kopaevich, L. F.. A.. M.. V.. "The Crimean Eocene Nummulite Bank". Moscow University Geology Bulletin. 63: 195–8. Doi:10.3103/S0145875208030083. Racey, Andrew. "A Review of Eocene Nummulite Accumulations: Structure and Reservoir Potential". Journal of Petroleum Geology. 24: 79–100. Bibcode:2001JPetG..24...79R. Doi:10.1111/j.1747-5457.2001.tb00662.x. Papazzoni, Cesare Andrea. "Nummulite biostratigraphy at the Middle/Upper Eocene boundary in the northern Mediterranean area". Rivista Italiana di Paleontologia e Stratigrafia. 101: 63–80. Guido, Adriano. "Automicrite in a'nummulite bank' from the Monte Saraceno: evidence for synsedimentary cementation". Sedimentology. 58: 878–889. Bibcode:2011Sedim..58..878G. Doi:10.1111/j.1365-3091.2010.01187.x
A locule or loculus is a small cavity or compartment within an organ or part of an organism. In angiosperms, the term locule refers to a chamber within an ovary of the flower and fruits. Depending on the number of locules in the ovary, fruits can be classified as uni-locular, bi-locular, tri-locular or multi-locular; the number of locules present in a gynoecium may be equal to or less than the number of carpels. The locules contain the seeds; the term may refer to chambers within anthers containing pollen. In Ascomycete fungi, locules are chambers within the hymenium in which the perithecia develop
Foraminifera are members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses. Tests of chitin are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment, while a smaller variety float in the water column at various depths. Fewer are known from freshwater or brackish conditions, some few soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in structure; these shells are made of calcium carbonate or agglutinated sediment particles. Over 50,000 species are recognized, both fossil, they are less than 1 mm in size, but some are much larger, the largest species reaching up to 20 cm. In modern Scientific English, the term foraminifera is both singular and plural, is used to describe one or more specimens or taxa: its usage as singular or plural must be determined from context.
Foraminifera is used informally to describe the group, in these cases is lowercase. The taxonomic position of the Foraminifera has varied since their recognition as protozoa by Schultze in 1854, there referred to as an order, Foraminiferida. Loeblich and Tappan reranked Foraminifera as a class as it is now regarded; the Foraminifera have been included in the Protozoa, or in the similar Protoctista or Protist kingdom. Compelling evidence, based on molecular phylogenetics, exists for their belonging to a major group within the Protozoa known as the Rhizaria. Prior to the recognition of evolutionary relationships among the members of the Rhizaria, the Foraminifera were grouped with other amoeboids as phylum Rhizopodea in the class Granuloreticulosa; the Rhizaria are problematic, as they are called a "supergroup", rather than using an established taxonomic rank such as phylum. Cavalier-Smith defines the Rhizaria as an infra-kingdom within the kingdom Protozoa; some taxonomies put the Foraminifera in a phylum of their own, putting them on par with the amoeboid Sarcodina in which they had been placed.
Although as yet unsupported by morphological correlates, molecular data suggest the Foraminifera are related to the Cercozoa and Radiolaria, both of which include amoeboids with complex shells. However, the exact relationships of the forams to the other groups and to one another are still not clear. Foraminifera are related to testate amoebae; the most recent taxonomy by Mikhalevich 2013. Foraminifera d'Orbigny 1826 Order Reticulomyxida Class Schizocladea Cedhagen & Mattson 1992 Order Schizocladida Class Xenophyophorea Schultze 1904 Order Stannomida Tendal 1972 Order Psamminida Tendal 1972 Class Astrorhizata Saidova 1981 Subclass Lagynana Mikhalevich 1980 Order Ammoscalariida Mikhalevich 1980 Order Lagynida Mikhalevich 1980 Order Allogromiida Loeblich & Tappan 1961 Subclass Astrorhizana Saidova 1981 Order Astrorhizida Lankester 1885 Order Dendrophryida Mikhalevich 1995 Order Hippocrepinida Saidova 1981 Order †Parathuramminida Mikhalevich 1980 Order Psammosphaerida Haeckel 1894 Class Rotaliata Mikhalevich 1980 Subclass Globigerinana Mikhalevich 1980 Order Cassigerinellida Mikhalevich 2013 Order Globigerinida Carpenter, Parker & Jones 1862 Order Hantkeninida Mikhalevich 1980 Order Heterohelicida Fursenko 1958 Order Globorotaliida Mikhalevich 1980 Subclass Textulariana Mikhalevich 1980 Order Nautiloculinida Mikhalevich 2003 Order Spiroplectamminida Mikhalevich 1992 Order Textulariida Delage & Hérouard 1896 Order Trochamminida Saidova 1981 (Carterinida Loeblich & Tappan 1955] Order Verneuilinida Mikhalevich & Kaminski 2003 Subclass Rotaliana Mikhalevich 1980 Superorder Robertinoida Mikhalevich 1980 Order Robertinida Mikhalevich 1980 Superorder Nonionoida Saidova 1981 Order Elphidiida Saidova 1981 Order Nummulitida Carpenter, Parker & Jones 1862 Order †Orbitoidida Copeland 1956 Order Nonionida Saidova 1981 Superorder Buliminoida Saidova 1981 Order Cassidulinida d’Orbigny 1839 Order Buliminida Saidova 1981 Order Bolivinitida Saidova 1981 Superorder Discorboida Ehrenberg 1838 Order Chilostomellida Haeckel 1894 Order Discorbida Ehrenberg 1838 Order Glabratellida Mikhalevich 1994 Order Planorbulinida Mikhalevich 1992 Order Rotaliida Lankester 1885 Order Rosalinida Delage & Hérouard 1896 Class Nodosariata Mikhalevich 1992 Subclass Hormosinana Mikhalevich 1992 Order Ammomarginulinida Mikhalevich 2002 Order Nouriida Mikhalevich 1980 Order †Pseudopalmulida Mikhalevich 1992 Order Saccamminida Lankester 1885 Order Hormosinida Mikhalevich 1980 Subclass Nodosariana Mikhalevich 1992 Order †Biseriamminida Mikhalevich 1981 Order Delosinida Revets 1989 Order Lagenida Delage & Hérouard 1896 Order †Palaeotextulariida Hohenegger & Piller 1975 Order Polymorphinida Mikhalevich 1980 Order Vaginulinida Mikhalevich 1993 Order Nodosariida Calkins 1926 Class Spirillinata Mikhalevich 1992 Subclass Ammodiscana Mikhalevich 1980 Order †Plagioraphida Mikhalevich 2003 Order Ammodiscida Mikhalevich 1980 Order Ammovertellinida Mikhalevich 1999 Order Ataxophragmiida Fursenko 1958 Subclass Spirillinana Mikhalevich 1992 Superorder †Archaediscoida Pojarkov & Skvortsov 1979 Order †Archaediscida Pojarkov & Skvortsov 1979 Order †Lasiodiscida
An estuary is a enclosed coastal body of brackish water with one or more rivers or streams flowing into it, with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments, they are subject both to marine influences—such as tides and the influx of saline water—and to riverine influences—such as flows of fresh water and sediment. The mixing of sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are classified according to their geomorphological features or to water-circulation patterns, they can have many different names, such as bays, lagoons, inlets, or sounds, although some of these water bodies do not meet the above definition of an estuary and may be saline.
The banks of many estuaries are amongst the most populated areas of the world, with about 60% of the world's population living along estuaries and the coast. As a result, many estuaries suffer degradation from a variety of factors including: sedimentation from soil erosion from deforestation and other poor farming practices; the word "estuary" is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus, meaning tide. There have been many definitions proposed to describe an estuary; the most accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, within which sea water is measurably diluted with freshwater derived from land drainage". However, this definition excludes a number of coastal water bodies such as coastal lagoons and brackish seas. A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff.
This broad definition includes fjords, river mouths, tidal creeks. An estuary is a dynamic ecosystem having a connection to the open sea through which the sea water enters with the rhythm of the tides; the sea water entering the estuary streams. The pattern of dilution varies between different estuaries and depends on the volume of fresh water, the tidal range, the extent of evaporation of the water in the estuary. Drowned river valleys are known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley; this is the most common type of estuary in temperate climates. Well-studied estuaries include the Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border; the width-to-depth ratio of these estuaries is large, appearing wedge-shaped in the inner part and broadening and deepening seaward. Water depths exceed 30 m.
Examples of this type of estuary in the U. S. are the Hudson River, Chesapeake Bay, Delaware Bay along the Mid-Atlantic coast, Galveston Bay and Tampa Bay along the Gulf Coast. Bar-built estuaries are found in place where the deposition of sediment has kept pace with rising sea level so that the estuaries are shallow and separated from the sea by sand spits or barrier islands, they are common in tropical and subtropical locations. These estuaries are semi-isolated from ocean waters by barrier beaches. Formation of barrier beaches encloses the estuary, with only narrow inlets allowing contact with the ocean waters. Bar-built estuaries develop on sloping plains located along tectonically stable edges of continents and marginal sea coasts, they are extensive along the Atlantic and Gulf coasts of the U. S. in areas with active coastal deposition of sediments and where tidal ranges are less than 4 m. The barrier beaches that enclose bar-built estuaries have been developed in several ways: building up of offshore bars by wave action, in which sand from the sea floor is deposited in elongated bars parallel to the shoreline, reworking of sediment discharge from rivers by wave and wind action into beaches, overwash flats, dunes, engulfment of mainland beach ridges due to sea level rise and resulting in the breaching of the ridges and flooding of the coastal lowlands, forming shallow lagoons, elongation of barrier spits from the erosion of headlands due to the action of longshore currents, with the spits growing in the direction of the littoral drift.
Barrier beaches form in shallow water and are parallel to the shoreline, resulting in long, narrow estuaries. The average water depth is less than 5 m, exceeds 10 m. Examples of bar-built estuaries are Barnegat Bay, New Jersey. Fjords were formed where pleistocene glaciers deepened and widened existing river valleys so that they become U-shaped in cross s