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Paleontology In Nevada
Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the United States, U.S. state of Nevada. Nevada has a rich fossil Fossil record, record of plants and animal life spanning the past 650 million years of time. The earliest fossils from the state are from Esmeralda County, Nevada, Esmeralda County, and are Late Proterozoic in age and represent stromatolite reefs of cyanobacteria, amongst these reefs were some of the oldest known shells in the fossil record, the Cloudinidae, Cloudina-fauna. Much of the Proterozoic and Paleozoic fossil story of Nevada is that of a warm, shallow, tropical sea, with a few exceptions towards the Late Paleozoic. As such, many fossils across the state are those of marine animals, such as trilobites, brachiopods, bryozoans, honeycomb corals, archaeocyaths, and horn corals. After the Paleozoic, tectonic activity on the western margin of North America increased. This increase in Tectonics, tectonism forced p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Map Of USA NV
A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on a transitory medium such as a computer screen. Some maps change interactively. Although maps are commonly used to depict geography, geographic elements, they may represent any space, real or fictional. The subject being mapped may be two-dimensional such as Earth's surface, three-dimensional such as Earth's interior, or from an abstract space of any dimension. Maps of geographic territory have a very long tradition and have existed from ancient times. The word "map" comes from the , wherein ''mappa'' meant 'napkin' or 'cloth' and ''mundi'' 'of the world'. Thus, "map" became a shortened term referring to a flat representation of Earth's surface. History Maps have been one of the most important human inventions for millennia, allowin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaurs
Ichthyosauria is an taxonomy (biology), order of large extinction, extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago (Myr, Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic Geologic time scale, epoch, ichthyosaurs and other Ichthyosauromorpha, ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurians were particularly abundant in the Late Triassic and Early Jurassic periods, until they were replaced as the top ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shonisaurus PopularisDB
''Shonisaurus'' is a genus of very large ichthyosaurs. At least 37 incomplete fossil specimens of the type species, ''Shonisaurus popularis'', have been found in the Luning Formation of Nevada, USA. This formation dates to the late Carnian-early Norian age of the Late Triassic, around 227 million years ago. Other possible species of ''Shonisaurus'' have been discovered from the middle Norian deposits of Canada and Alaska. Description left, Size of ''S. popularis'' (green) and '' Shastasaurus sikanniensis'' (red) compared with a human (blue) ''Shonisaurus'' lived during the late Carnian to Norian stages of the Late Triassic. With a large skull about long, ''S. popularis'' measured around in length and in body mass. ''S. sikanniensis'' was one of the largest marine reptiles of all time, measuring long and weighing . ''Shonisaurus'' had a long snout, and its flippers were much longer and narrower than in other ichthyosaurs. While ''Shonisaurus'' was initially reported to hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elko County, Nevada
Elko County is a County (United States), county in the northeastern corner of Nevada, United States. As of the 2020 United States census, 2020 census, the population was 53,702. Its county seat is Elko, Nevada, Elko. The county was established on March 5, 1869, from Lander County, Nevada, Lander County. Elko County is the fourth-largest County (United States), county by area in the contiguous United States, ranking lower when the List of boroughs and census areas in Alaska, boroughs of Alaska are included. It is List of the largest counties in the United States by area, one of only 10 counties in the U.S. with more than of area. Elko County is the second-largest county by area in Nevada, with only Nye County, Nevada, Nye County being larger. Elko County is part of the Elko micropolitan area, Elko micropolitan statistical area. It contains 49.8 percent of the Duck Valley Indian Reservation, set up in the late 19th century for the Shoshone-Paiute peoples; they are a federally reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Bonneville
Lake Bonneville was the largest Late Pleistocene paleolake in the Great Basin of western North America. It was a pluvial lake that formed in response to an increase in precipitation and a decrease in evaporation as a result of cooler temperatures. The lake covered much of what is now western Utah and at its highest level extended into present-day Idaho and Nevada. Many other hydrographically closed basins in the Great Basin contained expanded lakes during the Late Pleistocene, including Lake Lahontan in northwestern Nevada. Geologic description Shorelines of Lake Bonneville are visible above Salt Lake City along the western front of the Wasatch Mountains and on other mountains throughout the Bonneville basin.Gilbert, G.K., 1890. Lake Bonneville. U.S. Geological Survey Monograph 1. 438 pp. These shorelines appear as shelves or benches that protrude from the mountainside above the valley floor, are visible on the ground from long distances and on satellite images, and have both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Lahontan
Lake Lahontan was a large endorheic prehistoric lake during the Pleistocene that occupied modern northwestern Nevada and extended into northeastern California and southern Oregon. The area of the former lake is a large portion of the Great Basin that borders the Sacramento River watershed to the west. The lake was named by Clarence King during the Geological Exploration of the Fortieth Parallel. The name honors Louis-Armand de Lom d'Arce de Lahontan, Baron de Lahontan, a French soldier and explorer. History At its peak approximately 12,700 years ago (during a period known as the Sehoo Highstand), the lake had a surface area of over , with its largest component centered at the location of the present Carson Sink. Near present day Pyramid Lake the depth of the lake was then about and at what is present day Black Rock Desert. Lake Lahontan, during this most recent glacial period, would have been one of the largest lakes in North America. Climate change around the end of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluvial Lakes
A pluvial lake is a body of water that accumulated in a basin because of a greater moisture availability resulting from changes in temperature and/or precipitation. These intervals of greater moisture availability are not always contemporaneous with glacial periods. Pluvial lakes are typically closed lakes that occupied endorheic basins. Pluvial lakes that have since evaporated and dried out may also be referred to as ''paleolakes''.Goudie, A.S., 2013. ''and semi-arid geomorphology.'' Cambridge University Press. Etymology The word comes from the Latin ''pluvia'', which means "rain". Geology Pluvial lakes represent changes in the hydrological cycle: wet cycles generate large lakes, and dry cycles cause the lakes to recede. Accumulated sediments show the variation in water level. During glacial periods, when the lake level is fairly high, mud sediments will settle out and be deposited. At times in between glaciers (interglacial), salt deposits may be present because of the ari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the Phanerozoic eon. It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today); a proposed third epoch, the Anthropocene, was rejected in 2024 by IUGS, the governing body of the ICS. The Quaternary is typically defined by the Quaternary glaciation, the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the first period of the Cenozoic Era, the tenth period of the Phanerozoic and is divided into the Paleocene, Eocene, and Oligocene epochs. The earlier term Tertiary Period was used to define the time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. Paleogene is often abbreviated "Pg", although the United States Geological Survey uses the abbreviation "" for the Paleogene on the Survey's geologic maps. Much of the world's modern vertebrate diversity originated in a rapid surge of diversification in the early Paleogene, as survivors of the Cretaceous–Paleogene extinction event took advantage of empty ecolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basin And Range Province
The Basin and Range Province is a vast United States physiographic region, physiographic region covering much of the inland Western United States and Northern Mexico, northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins. The physical geography, physiography of the province is the result of Extensional tectonics, tectonic extension that began around 17 million years ago in the early Miocene epoch. The numerous ranges within the province in the United States are collectively referred to as the "Great Basin Ranges", although many are not actually in the Great Basin. Major ranges include the Snake Range, the Panamint Range, the White Mountains (California), White Mountains, and the Sandia Mountains. The highest point fully within the province is White Mountain Peak in California, while the lowest point is the Badwater Basin in Death Valle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three geological eras of the Phanerozoic Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians ( placentals) in the Northern Hemisphere and the metatherians (marsupials, now mainly restricted to Australia and to some extent South America) in the Southern Hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that large m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
