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Fusulinid
The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period. Taxonomy Thirteen superfamilies are presently recognised, based on taxa (families) included in the three superfamilies given in the Treatise. Three are based on families in the Parathuramminacea, 1964, and 2.9 million families in the Endothyracea, 1964. The Fusulinacea remains the same in both sources (Treatise 1964 and Loeblich and Tappan, 1988). The term fusulinata has traditionally been used to refer to all palaeozoic for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusulinid Limestone, Upper Pennsylvanian; Elk County KS
The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period. Taxonomy Thirteen superfamilies are presently recognised, based on taxa (families) included in the three superfamilies given in the Treatise. Three are based on families in the Parathuramminacea, 1964, and 2.9 million families in the Endothyracea, 1964. The Fusulinacea remains the same in both sources (Treatise 1964 and Loeblich and Tappan, 1988). The term fusulinata has traditionally been used to refer to all palaeozoic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera Test
Foraminiferal tests are the tests (or shells) of Foraminifera. Foraminifera (''forams'' for short) are single-celled predatory protists, mostly marine, and usually protected with shells. These shells, often called tests, can be single-chambered or have multiple interconnected chambers; the cellular machinery is contained within the shell. So important is the test to the biology of foraminifera that it provides the scientific name of the group—''foraminifera'', Latin for "hole bearers", referring to the pores connecting chambers of the shell in the multi-chambered species. Foraminiferal tests are usually made of calcite, a form of calcium carbonate (), but are sometimes made of aragonite, agglutinated sediment particles, chitin, or (rarely) of silica. Other foraminifera lack tests altogether. Over 50,000 species are recognized, both living (6,700 - 10,000)Ald, S.M. ''et al.'' (2007Diversity, Nomenclature, and Taxonomy of Protists ''Syst. Biol.'' 56(4), 684–689, DOI: 10.1080/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nodosinellacea
The Nodosinellacea is a superfamily of fusulinids (microganular foraminifera) in which the test is of one or more distinct chambers with the wall single layered or with a microgranular outer layer and fibrous inner layer. Differs from the Geinitzinacea in that the latter has the layers reversed. The Nodosinellacea, which has a stratigraphic range from the Upper Silurian to the Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ..., includes two families, the Earlandinitidae and the Nodosinellidae. References * * Alfred R. Loeblich Jr and Helen Tappan,1988. Forminiferal Genera and their Classification. Van Nostrand Reinhold. {{Taxonbar, from=Q7046732 Foraminifera superfamilies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian–Triassic Extinction Event
The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 251.9 million years ago. It is the Earth's most severe known extinction event, with the extinction of 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. It was the largest known mass extinction of insects. There is evidence for one to three distinct pulses, or phases, of extinction. The scientific consensus is that the main cause of extinction was the large amount of carbon dioxide emitted by the volcanic eruptions that created the Siberian Traps, which elevated global temperatures, and in the oceans led to widespread anoxia and acidification. Proposed contributing factors include: the emission of much additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viséan
The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from to Ma. It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage. Name and definitions The Viséan Stage was introduced by Belgian geologist André Dumont in 1832. Dumont named this stage after the city of Visé in Belgium's Liège Province. Before being used as an international stage, the Visean Stage was part of the (West) European regional geologic time scale, in which it followed the Tournaisian Stage and is followed by the Namurian Stage. In the North American regional scale, the Visean Stage correlates with the upper Osagean, the Meramecian and lower Chesterian stages. In the Chinese regional time scale, it correlates with the lower and middle Tatangian series.; 2006: ''Global time scale and regional stratigraphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geinitzinacea
The Geintizinacea comprises a superfamily of Upper Devonian to Upper Permian uniserial fusulinids The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was dif ... (microgranular foraminifera with chambers aligned in a single row), the chamber walls consisting of a dark microgranular inner layer and radially fibrous outer layer. Advanced forms show secondary lateral thickening The Geinitzinacea differs from the Nodosinellacea in that in the Nodosinellacea the inner layer is fibrous. Two families are included, the Geinitzinidae and Pachyphloiidae. References * * Alfred R. Loeblich Jr and Helen Tappan,1988. Forminiferal Genera and their Classification. Van Nostrand Reinhold. {{Taxonbar, from=Q5530156 Foraminifera superfamilies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moravamminacea
The Moravamminacea is a superfamily of foraminifera within Fusulinida that comprises genera in which the proloculus (initial chamber) is followed by a coiled or straight second chamber, and in which periods of growth result in partial or incipient septa. Contains three families, Caligellidae, Moravamminidae, and Paratickenellidae, with an overall range from the upper Silurian to the Lower Carboniferous (Mississippian). In older classifications (e.g. Loeblich and Tappan 1964) these were the Moravaminninae, a subfamily within the Parathuraminacea, as then defined. References *Alfred R. Loeblich Jr and Helen Tappan, 1964. Sarcodina Chiefly "Thecamoebians" and Foraminiferida; Treatise on Invertebrate Paleontology, part C Protista 2. Geological Society of America and University of Kansas Press. R.C. Moore (ed) *Alfred R. Loeblich Jr and Helen Tappan,1988. Forminiferal Genera and their Classification. Van Nostrand Reinhold. {{Taxonbar, from=Q16997057 Foraminifera superfamilie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods ( myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
