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M. Exilis
The pygmy mammoth or Channel Islands mammoth (''Mammuthus exilis'') is an extinct species of dwarf elephant descended from the Columbian mammoth (''M. columbi'') of mainland North America. This species became extinct during the Quaternary extinction event in which many megafauna species became extinct due to changing conditions to which the species could not adapt. A case of island or insular dwarfism, from a recent analysis in 2010 it was determined that ''M. exilis'' was on average, tall at the shoulders and in weight, in stark contrast to its tall, ancestor. Another estimate gives a shoulder height of and a weight of . Discovery Mammoth remains have been known on the northern Channel Islands of California since 1856. They were first reported in scientific literature in 1873. In 1994 the National Park Service called in scientists to inspect an uncovered, unidentified skeleton found on the northeast coast of Santa Rosa Island. They found bones of the axial skeleton of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insular Dwarfism
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing. This process has occurred many times throughout evolutionary history, with examples including dinosaurs, like '' Europasaurus'' and ''Magyarosaurus dacus'', and modern animals such as elephants and their relatives. This process, and other "island genetics" artifacts, can occur not only on islands, but also in other situations where an ecosystem is isolated from external resources and breeding. This can include caves, desert oases, isolated valleys and isolated mountains ("sky islands"). Insular dwarfism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tusk
Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with pigs and walruses, or, in the case of elephants, elongated incisors. Tusks share common features such as extra-oral position, growth pattern, composition and structure, and lack of contribution to ingestion. Tusks are thought to have adapted to the extra-oral environments, like dry or aquatic or arctic. In most tusked species both the males and the females have tusks although the males' are larger. Most mammals with tusks have a pair of them growing out from either side of the mouth. Tusks are generally curved and have a smooth, continuous surface. The male narwhal's straight single helical tusk, which usually grows out from the left of the mouth, is an exception to the typical features of tusks described above. Continuous growth of tusks is enabled by formative tissues in the apical openings of the roots of the teeth. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smilodon
''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. ''Smilodon'' lived in the Americas during the Pleistocene epoch (2.5 Year#mya, mya – 10,000 years ago). The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth". Three species are recognized today: ''S. gracilis'', ''S. fatalis'', and ''S. populator''. The two latter species were probably descended from ''S. gracilis'', which itself probably evolved from ''Megantereon''. The hundreds of individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of ''Smilodon'' fossils. Overall, ''Smilodon'' was more robustly built than any Neontology, extant cat, with particularly well-d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dire Wolf
The dire wolf (''Aenocyon dirus'' ) is an extinct canine. It is one of the most famous prehistoric carnivores in North America, along with its extinct competitor ''Smilodon''. The dire wolf lived in the Americas and eastern Asia during the Late Pleistocene and Early Holocene epochs (125,000–9,500 years ago). The species was named in 1858, four years after the first specimen had been found. Two subspecies are recognized: ''Aenocyon dirus guildayi'' and ''Aenocyon dirus dirus''. The largest collection of its fossils has been obtained from the Rancho La Brea Tar Pits in Los Angeles. Dire wolf remains have been found across a broad range of habitats including the plains, grasslands, and some forested mountain areas of North America, the arid savanna of South America, and the steppes of eastern Asia. The sites range in elevation from sea level to . Dire wolf fossils have rarely been found north of 42°N latitude; there have been only five unconfirmed reports above this latitude. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammoth
A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, in northern species, a covering of long hair. They lived from the Pliocene epoch (from around 5 million years ago) into the Holocene at about 4,000 years ago, and various species existed in Africa, Europe, Asia, and North America. They were members of the family Elephantidae, which also contains the two genera of modern elephants and their ancestors. Mammoths are more closely related to living Asian elephants than African elephants. The oldest representative of ''Mammuthus'', the South African mammoth (''M. subplanifrons''), appeared around 5 million years ago during the early Pliocene in what is now southern and eastern Africa. Descendant species of these mammoths moved north and continued to propagate into numerous subsequent spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygmy Mammoth Jawbone - Cleveland Museum Of Natural History - 2014-12-26
In anthropology, pygmy peoples are ethnic groups whose average height is unusually short. The term pygmyism is used to describe the phenotype of endemic short stature (as opposed to disproportionate dwarfism occurring in isolated cases in a population) for populations in which adult men are on average less than tall. The term is primarily associated with the African Pygmies, the hunter-gatherers of the Congo Basin (comprising the Bambenga, Bambuti and Batwa). The terms "Asiatic Pygmies" and "Oceanian pygmies" have been used to describe the Negrito populations of Southeast Asia and Australo-Melanesian peoples of short stature. The Taron people of Myanmar are an exceptional case of a "pygmy" population of East Asian phenotype. Etymology The term ''pygmy'', as used to refer to diminutive people, derives from Greek πυγμαῖος ''pygmaios'' via Latin ''Pygmaei'' (sing. ''Pygmaeus''), derived from πυγμή – meaning a short forearm cubit, or a measure of length corres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the United States. The publication has won more than 40 Pulitzer Prizes. It is owned by Patrick Soon-Shiong and published by the Times Mirror Company. The newspaper’s coverage emphasizes California and especially Southern California stories. In the 19th century, the paper developed a reputation for civic boosterism and opposition to labor unions, the latter of which led to the bombing of its headquarters in 1910. The paper's profile grew substantially in the 1960s under publisher Otis Chandler, who adopted a more national focus. In recent decades the paper's readership has declined, and it has been beset by a series of ownership changes, staff reductions, and other controversies. In January 2018, the paper's staff voted to unionize and final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chumash People
The Chumash are a Native American people of the central and southern coastal regions of California, in portions of what is now San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties, extending from Morro Bay in the north to Malibu in the south. Their territory included three of the Channel Islands: Santa Cruz, Santa Rosa, and San Miguel; the smaller island of Anacapa was likely inhabited seasonally due to the lack of a consistent water source. Modern place names with Chumash origins include Malibu, Nipomo, Lompoc, Ojai, Pismo Beach, Point Mugu, Port Hueneme, Piru, Lake Castaic, Saticoy, Simi Valley and Somis. Archaeological research demonstrates that the Chumash people have deep roots in the Santa Barbara Channel area and lived along the southern California coast for millennia. History Prior to European contact (pre-1542) Indigenous peoples have lived along the California coast for at least 11,000 years. Sites of the Millingstone Horizon date from 7000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arlington Springs Man
The Arlington Springs man is a set of Late Pleistocene human remains discovered in 1959 on Santa Rosa Island, one of the Channel Islands located off the coast of Southern California. The Arlington Springs archeological site is protected within northern Channel Islands National Park, and in Santa Barbara County. History Archaeology In 1959–1960, two femora were excavated by Phil C. Orr, curator of anthropology and paleontology at the Santa Barbara Museum of Natural History, at Arlington Springs on Santa Rosa Island. Orr believed the remains were those of a 10,000-year-old man and dubbed them the "Arlington Springs Man". The Arlington Springs Man was later re-examined in 1989 by Orr's successors at the museum, Dr. John R. Johnson and Don Morris. The two came to the initial assessment that the Arlington Springs Man was actually the "Arlington Springs Woman". Radiocarbon dating determined that the remains dated to 13,000 years BP, making the remains potentially the oldest-known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Rosae
Santa Rosae (also spelled Santarosae) was, before the end of the last ice age, an ancient landmass off the coast of present-day southern California, near Santa Barbara County and Ventura County, of which the northern Channel Islands of California are remnants. At its largest, Santa Rosae was roughly 3-4 times bigger than the northern Channel Islands of today, nearly 125 km (77.67 miles) long from east to west. Between about 20,000 and 5,000 years ago, Santa Rosae lost about 70% of its land mass to post-glacial rising sea level, leaving behind a vast submerged landscape currently being explored by scientists. San Miguel, Santa Rosa, Santa Cruz, and Anacapa Island comprise the unsubmerged portions of Santa Rosae today. This island was about 5 miles offshore. It broke up between about 11,000 and 9,000 years ago, and the present northern Channel Islands took their shape after the continental ice sheets melted and sea levels rose by about 100 meters. There is evidence to suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
