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Southern Elephant Seal
The southern elephant seal (''Mirounga leonina'') is one of two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets its name from its massive size and the large proboscis of the adult male, which is used to produce very loud roars, especially during the breeding season. A bull southern elephant seal is about 40% heavier than a male northern elephant seal (''Mirounga angustirostris''), which is nearly twice the weight of a male walrus (''Odobenus rosmarus''), or 6–7 times heavier than the largest living mostly terrestrial carnivorans, the Kodiak bear and the polar bear. Taxonomy The southern elephant seal was one of the many species originally described by Swedish zoologist Carl Linnaeus in the landmark 1758 10th edition of his ''Systema Naturae'', where it was given the binomial name of ''Phoca leonina''. John Edward Gray established the genus ''Mirou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from 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 () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Elephant Seal
The northern elephant seal (''Mirounga angustirostris'') is one of two species of elephant seal (the other is the southern elephant seal). It is a member of the family Phocidae (true seals). Elephant seals derive their name from their great size and from the male's large proboscis, which is used in making extraordinarily loud roaring noises, especially during the mating competition. Sexual dimorphism in size is great. Correspondingly, the mating system is highly polygynous; a successful male is able to impregnate up to 50 females in one season. Description The huge male northern elephant seal typically weighs and measures , although some males can weigh up to . Females are much smaller and can range from in weight, or roughly a third of the male's bulk, and measure from . The bull southern elephant seals are, on average, larger than those in the northern species, but the females in both are around the same size, indicating the even higher level of sexual dimorphism in the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Thewissen
Gerardus arie (Hans) Thewissen is a Dutch-American paleontologister known for his significant contributions to the field of whale evolution. Thewissen's fieldwork has led to the discovery of key fossils that have shed light on the transition of whales from land to water, including the discovery of ''Ambulocetus'', ''Pakicetus'', ''Indohyus'', and ''Kutchicetus''. In addition to his work on fossil discoveries, Thewissen also studies modern bowhead and Beluga whale, beluga whales in Alaska, focusing on their biology and the implications of this knowledge for management and conservation efforts. His research has been instrumental in deepening our understanding of cetacean evolution and the adaptations that allowed these mammals to transition from terrestrial to fully aquatic lifestyles. Early life Thewissen has always been interested in paleontology and natural history. His mother said that when Thewissen was a small boy, she had to sort through his pockets before laundry time to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, dioecious species, which consist of most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male-male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', when both biological sexes are phenotype, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirounga Leonina 01
Elephant seals or sea elephants are very large, oceangoing earless seals in the genus ''Mirounga''. Both species, the northern elephant seal (''M. angustirostris'') and the southern elephant seal (''M. leonina''), were hunted to the brink of extinction for lamp oil by the end of the 19th century, but their numbers have since recovered. They can weigh up to . Despite their name, elephant seals are not closely related to elephants, and the large proboscis or Elephant trunk, trunk that males of the species possess is an example of Convergent evolution, convergent evolution. The northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S., Canada and Mexico. The most northerly breeding location on the Pacific Coast is at Race Rocks Marine Protected Area, at the southern tip of Vancouver Island in the Strait of Juan de Fuca. The southern elephant seal is found in the Southern Hemisphere on islands such as South Georgia and Macquari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systema Naturae
' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomenclature, was partially developed by the Bauhin brothers, Gaspard Bauhin, Gaspard and Johann Bauhin, Johann, Linnaeus was the first to use it consistently throughout his book. The first edition was published in 1735. The full title of the 10th edition (1758), which was the most important one, was ', which appeared in English in 1806 with the title: "A General System of Nature, Through the Three Grand Kingdoms of Animals, Vegetables, and Minerals, Systematically Divided Into their Several Classes, Orders, Genera, Species, and Varieties, with their Habitations, Manners, Economy, Structure and Peculiarities". The 10th edition of Systema Naturae, tenth edition of this book (1758) is considered the starting point of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoology
Zoology ( , ) is the scientific study of animals. Its studies include the anatomy, structure, embryology, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and how they interact with their ecosystems. Zoology is one of the primary branches of biology. The term is derived from Ancient Greek , ('animal'), and , ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and used this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. Modern zoology has its origins during the Renaissance and early modern period, with Carl Linnaeus, Antonie van Leeuwenhoek, Robert Hooke, Charles Darwin, Gregor Mendel a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammalia In The 10th Edition Of Systema Naturae
The Mammalia in the 10th edition of ''Systema Naturae'' forms one of six classes of animals in Carl Linnaeus's tenth reformed edition written in Latin. The following explanations are based on William Turton's translations who rearranged and corrected earlier editions published by Johann Friedrich Gmelin, Johan Christian Fabricius and Carl Ludwig Willdenow: Animals that suckle their young by means of lactiferous teats. In external and internal structure they resemble man: most of them are quadrupeds; and with man, their natural enemy, inhabit the surface of the Earth. The largest, though fewest in number, inhabit the ocean. Linnaeus divided the mammals based on the number, situation, and structure of their teeth; mammals have the following characteristics: *Heart: two auricles, 2 ventricles. Warm, dark red blood; *Lungs: respires alternately; *Jaw: incombent, covered. Teeth usually within jaw; *Teats: lactiferous; *Organs of sense: tongue, nostrils, eyes, ears, and papillae of the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceana (non-profit Group)
Oceana, inc. is a 501(c)(3) nonprofit ocean conservation organization focused on influencing specific policy decisions on the national level to preserve and restore the world's oceans. It is headquartered in Washington, D.C., with offices in Juneau, Monterey, Fort Lauderdale, New York, Portland, Toronto, Mexico City, Madrid, Brussels, Copenhagen, Geneva, London, Manila, Belmopan, Brasília, Santiago, and Lima, and it is the largest international advocacy group dedicated entirely to ocean conservation. Currently, Oceana has a staff of about 200 and 6,000 volunteers, and it has almost 50 million dollars of revenue (as of 2017). Oceana takes a multi-faceted approach to ocean conservation; It conducts its own scientific research in addition to making policy recommendations, lobbying for specific legislation, and filing and litigating lawsuits. History Oceana was established in 2001 by an international group of leading foundations including the Rockefeller Brothers Fund, Sandler F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Bear
The polar bear (''Ursus maritimus'') is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can Hybrid (biology), interbreed. The polar bear is the largest extant species of bear and land carnivore, with adult males weighing . The species is sexually dimorphic, as adult females are much smaller. The polar bear is white- or yellowish-furred with black skin and a thick layer of fat. It is more slender than the brown bear, with a narrower skull, longer neck and lower shoulder hump. Its teeth are sharper and more adapted to cutting meat. The paws are large and allow the bear to walk on ice and paddle in the water. Polar bears are both terrestrial and Pagophily, pagophilic (ice-living) and are considered marine mammals because of their dependence on marine ecosystems. They prefer the annual sea ice but live on land when the ice melts in the summer. They are mostly carnivorous and specialized for preying on pinniped, se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kodiak Bear
The Kodiak bear (''Ursus arctos middendorffi''), also known as the Kodiak brown bear and sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is one of the largest recognized subspecies or population of the brown bear, and one of the two largest bears alive today, the other being the polar bear. They are also considered by some to be a population of grizzly bears. Physiologically and physically, the Kodiak bear is very similar to the other brown bear subspecies, such as the mainland grizzly bear (''Ursus arctos horribilis'') and the extinct California grizzly bear (''U. a. californicus''), with the main difference being size, as Kodiak bears are on average 1.5 to 2 times larger than their cousins. Despite this large variation in size, the diet and lifestyle of the Kodiak bear do not differ greatly from those of other brown bears. Kodiak bears have interacted with humans for centuries, especially hunters and other people in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
