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Isotelus
''Isotelus'' is a genus of asaphid trilobites from the middle and upper Ordovician period, fairly common in the Northeastern United States, northwest Manitoba, southwestern Quebec and southeastern Ontario. One species, ''Isotelus rex,'' is currently the world's largest trilobite ever found as a complete fossil, and was probably exceeded in size only by '' Hungioides bohemicus,'' in which the specimens probably exceeding ''Isotelus rex'' in size are only known from partial remains. Discovery and naming A specimen of ''Isotelus rex'', from Churchill, Manitoba, is the largest complete trilobite ever found. Discovered by Dave Rudkin ( Royal Ontario Museum), Robert Elias (University of Manitoba), Graham Young (Manitoba Museum) and Edward Dobrzanske (Manitoba Museum) in 1999, it measures in length, in maximum width (across the cephalon) and in maximum height (at the posterior midpoint of the cephalon). A number of species have been described: *''I. aktchokensis'' Weber, 1948 *' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verulam Formation
The Verulam Formation is a geologic formation and Lagerstätte in Ontario, Canada. It preserves fossils dating back to the Katian stage of the Ordovician period, or Shermanian to Chatfieldian in the regional stratigraphy. Description The Verulam Formation belongs to the Simcoe Group and overlies the Bobcaygeon Formation. Both the Bobcaygeon and Verulam Formations are composed of bioclastic wackestones, grainstones, and packstones interbedded with calcareous shales and siltstones. The Verulam contains more shale than the underlying Bobcaygeon Formation. Several hardgrounds have been documented in detail from the upper Bobcaygeon and lower Verulam. The paleoenvironments in which the Bobcaygeon and Verulam Formations were deposited have been interpreted as a proximal carbonate shelf that ranged in depth and proximity from shoal to shallow shelf in the Bobcaygeon and from deep shelf to shoal or shallow shelf in the Verulam Formation. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio
Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-largest by area, and with a population of nearly 11.8 million, is the List of U.S. states and territories by population, seventh-most populous and List of U.S. states and territories by population density, tenth-most densely populated. The state's capital and List of cities in Ohio, largest city is Columbus, Ohio, Columbus, with the Columbus metropolitan area, Ohio, Columbus metro area, Cincinnati metropolitan area, Greater Cincinnati, and Greater Cleveland being the List of metropolitan statistical areas, largest metropolitan areas. Ohio is bordered by Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the west, and Michigan to the northwest. Ohio is historically known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromide Formation
The Bromide Formation is a geological formation in Oklahoma, USA. It is well known for its diverse echinoderm and trilobite fossil fauna. Location The Bromide Formation crops out in the Arbuckle and Wichita Mountains and in the Criner Hills of Southern Oklahoma. It appears at the surface in particular within Carter, Johnston, Murray and Pontotoc counties (34.0° N, 97.0° W). Stratigraphy The Bromide Formation is the uppermost part of the Simpson Group, and originates from the Upper Ordovician (early Sandbian). This mostly carbonate succession is divided into the Mountain Lake and overlying Pooleville members. Although it primarily consists of limestone, limestone interbedded with shale, and sandstone, also occur. The Bromide Formation is a shallow water marine sediment.Bauer, J.A. Conodonts from the Bromide Formation (Middle Ordovician), South-Central Oklahoma. Journal of Paleontology 68-2 (1994). Much of the Mountain Lake Member comprises meter-scale, deep ramp cyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Life Of Quebec
The Paleozoic (or Palaeozoic) Era is the earliest of three era (geology), geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Ancient Greek, Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six period (geology), geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phylum, phyla first appeared. Arthropods, Mollusca, molluscs, fish, amphibians, reptiles, and synapsids all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Life Of Ontario
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct Animals Of North America
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asaphida Genera
Asaphida is a large, morphologically diverse order (biology), order of trilobites found in marine Stratum, strata dated from the Middle Cambrian until their extinction during the Silurian. Asaphida contains six Superfamily (zoology), superfamilies (Anomocaroidea, Asaphoidea, Cyclopygoidea, Dikelocephaloidea, Remopleuridoidea and Trinucleioidea), but no suborders. Asaphids comprise some 20% of described fossil trilobites. In 2020, the superfamily Trinucleoidea was proposed to be raised to an order (Trinucleida) and removed from Asaphida. Morphology The Asaphids generally have cephalon (arthropod anatomy), cephalon (head) and pygidium (tail) parts similar in size, and most species have a prominent median ventral suture. Heads are often flat, and carapace furrows in the head area are often faint or not visible. Thoracic segments typically number 5 - 12, though some species have as few as two and some as many as 30. They also generally have a wide doublure, or rim, that surrounds t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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