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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''), twice as heavy as a male walrus (''Odobenus rosmarus''), and 6–7 times heavier than the largest living mostly-terrestrial carnivoran, the polar bear (''Ursus maritimus'') and the Kodiak bear (''Ursus arctos middendorffi''),. 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 Edw ... [...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] |
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 (biology), family Phocidae (true seal (mammal), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Thewissen
Hans Thewissen is a Dutch-American paleontologist. His field work has discovered fossils for the steps in the transition from land to water in whales: '' Ambulocetus'', '' Pakicetus'', ''Indohyus'' and '' Kutchicetus''. He now studies modern bowhead and beluga whales in Alaska to learn about their biology and their implications for management and conservation. 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 take out the rocks and worms he collected. His father used to take him to the town of Maastricht, and they collected fossils from the Maastrichtian period. 12th birthday present was a rock hammer, which has accompanied him on all collecting trips since. He grew up just 2 miles from Liessel, a fossil locale that yielded the first whales he ever collected. Educational background After finishing Gymnasium secondary education in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray, FRS (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 zoologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systema Naturae
' (originally in Latin written ' with the ligature æ) is one of the major works of the 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 and Johann, Linnaeus was 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 ' or translated: "System of nature through the three kingdoms of nature, according to classes, orders, genera and species, with characters, differences, synonyms, places". The tenth edition of this book (1758) is considered the starting point of zoological nomenclature. In 1766–1768 Linnaeus published the much enhanced 12th edition, the last under his authorship. Another again enhanced work in the same style and titled "'" was published by Johann Friedrich Gmelin between 1788 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoology
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and how they interact with their ecosystems. 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 made use of 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. The Greek physician Galen studied human anatomy and was one of the greatest surgeons of the 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 upon 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 t ... [...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, Alaska, Monterey, California, Fort Lauderdale, Florida, New York City, New York, Portland, Oregon, Toronto, Ontario, Mexico City, Madrid, Brussels, Copenhagen, Geneva, London, Manila, Belmopan, Brasilia, 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 foundat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kodiak Bear
The Kodiak bear (''Ursus arctos middendorffi''), also known as the Kodiak brown bear, sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is 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, 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. While there is generally much variation in size between brown bears in different areas, most usually weigh between 115 and 360 kg (254 and 794 lb). The Kodiak bear, on the other hand, commonly reaches sizes of , and has even been known to exceed a weight of . Despite this large variation in size, the diet and lifestyle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Bear
The polar bear (''Ursus maritimus'') is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear species, as well as the largest extant land carnivore. A boar (adult male) weighs around , while a sow (adult female) is about half that size. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice and open water, and for hunting seals, which make up most of its diet. Although most polar bears are born on land, they spend most of their time on the sea ice. Their scientific name means "maritime bear" and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present. Because of their dependence on the sea ice, polar be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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