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Tusks (53652079298)
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. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanzanian Elephant
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and the Indian Ocean to the east; Mozambique and Malawi to the south; Zambia to the southwest; and Rwanda, Burundi, and the Democratic Republic of the Congo to the west. Mount Kilimanjaro, Africa's highest mountain, is in northeastern Tanzania. According to the United Nations, Tanzania has a population of million, making it the most populous country located entirely south of the equator. Many important hominid fossils have been found in Tanzania, such as 6-million-year-old Pliocene hominid fossils. The genus Australopithecus ranged across Africa between 4 and 2 million years ago, and the oldest remains of the genus ''Homo'' are found near Lake Olduvai. Following the rise of '' Homo erectus'' 1.8 million years ago, humanity spread ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivory Trade
The ivory trade is the commercial, often illegal trade in the ivory tusks of the hippopotamus, walrus, narwhal, mammoth, and most commonly, African and Asian elephants. Ivory has been traded for hundreds of years by people in Africa and Asia, resulting in restrictions and bans. Ivory was formerly used to make piano keys and other decorative items because of the white color it presents when processed but the piano industry abandoned ivory as a key covering material in the 1980s in favor of other materials such as plastic. Also, synthetic ivory has been developed which can be used as an alternative material for making piano keys. Elephant ivory Elephant ivory has been exported from Africa and Asia for millennia with records going back to the 14th century BCE. Transport of the heavy commodity was always difficult, and with the establishment of the early-modern slave trades from East and West Africa, freshly captured slaves were used to carry the heavy tusks to the ports where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal Anatomy
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eco-economic Decoupling
In economic and environmental fields, decoupling refers to an economy that would be able to grow without corresponding increases in environmental pressure. In many economies, increasing production (GDP) currently raises pressure on the environment. An economy that would be able to sustain economic growth while reducing the amount of resources such as water or fossil fuels used and delink environmental deterioration at the same time would be said to be decoupled. Environmental pressure is often measured using emissions of pollutants, and decoupling is often measured by the emission intensity of economic output. Examples of absolute long-term decoupling are rare, but recently some industrialized countries have decoupled GDP growth from both production- and, to a lesser extent, consumption-based emissions. In countries and economic markets where decoupling may be identified, one explanation could be the transition to a service economy. This hypothesis has been expanded upon by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivory Trade
The ivory trade is the commercial, often illegal trade in the ivory tusks of the hippopotamus, walrus, narwhal, mammoth, and most commonly, African and Asian elephants. Ivory has been traded for hundreds of years by people in Africa and Asia, resulting in restrictions and bans. Ivory was formerly used to make piano keys and other decorative items because of the white color it presents when processed but the piano industry abandoned ivory as a key covering material in the 1980s in favor of other materials such as plastic. Also, synthetic ivory has been developed which can be used as an alternative material for making piano keys. Elephant ivory Elephant ivory has been exported from Africa and Asia for millennia with records going back to the 14th century BCE. Transport of the heavy commodity was always difficult, and with the establishment of the early-modern slave trades from East and West Africa, freshly captured slaves were used to carry the heavy tusks to the ports where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fang
A fang is a long, pointed tooth. In mammals, a fang is a modified maxillary tooth, used for biting and tearing flesh. In snakes, it is a specialized tooth that is associated with a venom gland (see snake venom). Spiders also have external fangs, which are part of the chelicerae. Fangs are most common in carnivores or omnivores, but some herbivores, such as fruit bats, have them as well. They are generally used to hold or swiftly kill prey, such as in large cats. Omnivorous animals, such as bears, use their fangs when hunting fish or other prey, but they are not needed for consuming fruit. Some apes also have fangs, which they use for threats and fighting. However, the relatively short canines of humans are not considered to be fangs. Fangs in religion, mythology and legend Certain mythological and legendary creatures such as dragons, gargoyles and yakshas are commonly depicted with prominent fangs. The fangs of vampires are one of their defining characteristics. The iconogra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odobenocetops
''Odobenocetops'' () is an extinct genus of small toothed whale known from Peru and Chile. Its fossils are found in Neogene-aged marine strata dating from the Tortonian to the Zanclean. It had two tusks, and, in some fossils, one tusk was longer than the other. Phylogeny ''Odobenocetops'' can be identified as a cetacean based on several features unique to this order: # The presence of large air sinuses in the auditory region connected to large pterygoid sinuses. # The large supraorbital process of the frontal bone overhanging the orbital region. # Narial fossae opening dorsally (thought not at the apex of the skull like in other cetaceans.) # The absence of a true cribriform plate (a bony blade separating the nares). In ''Odobenocetops'', a group of foramina in this plate allows the passage of olfactory nerves connected to the small olfactory lobes in the brain. In other cetaceans, the olfactory nerves are similarly present but strongly reduced. # The elbow joint is immobile, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wild Boar
The wild boar (''Sus scrofa''), also known as the wild swine, common wild pig, Eurasian wild pig, or simply wild pig, is a suid native to much of Eurasia and North Africa, and has been introduced to the Americas and Oceania. The species is now one of the widest-ranging mammals in the world, as well as the most widespread suiform. It has been assessed as least concern on the IUCN Red List due to its wide range, high numbers, and adaptability to a diversity of habitats. It has become an invasive species in part of its introduced range. Wild boars probably originated in Southeast Asia during the Early Pleistocene and outcompeted other suid species as they spread throughout the Old World. , up to 16 subspecies are recognized, which are divided into four regional groupings based on skull height and lacrimal bone length. The species lives in matriarchal societies consisting of interrelated females and their young (both male and female). Fully grown males are usually solitary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbian Mammoth
The Columbian mammoth (''Mammuthus columbi'') is an extinct species of mammoth that inhabited the Americas as far north as the Northern United States and as far south as Costa Rica during the Pleistocene epoch. It was one of the last in a line of mammoth species, beginning with '' Mammuthus subplanifrons'' in the early Pliocene. DNA studies show that the Columbian mammoth was a hybrid species between woolly mammoths and another lineage descended from steppe mammoths; the hybridization happened more than 420,000 years ago. The pygmy mammoths of the Channel Islands of California evolved from Columbian mammoths. The closest extant relative of the Columbian and other mammoths is the Asian elephant. Reaching at the shoulders and in weight, the Columbian mammoth was one of the largest species of mammoth. It had long, curved tusks and four molars, which were replaced six times during the lifetime of an individual. It most likely used its tusks and trunk like modern elephants—for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warthog
''Phacochoerus'' is a genus in the family Suidae, commonly known as warthogs (pronounced ''wart-hog''). They are pigs who live in open and semi-open habitats, even in quite arid regions, in sub-Saharan Africa. The two species were formerly considered conspecific under the scientific name ''Phacochoerus aethiopicus'', but today this is limited to the desert warthog, while the best-known and most widespread species, the common warthog (or simply warthog), is ''Phacochoerus africanus''. Skull Although covered in bristly hairs, their bodies and heads appear largely naked from a distance, with only the crest along the back, and the tufts on their cheeks and tails being obviously haired. The English name refers to their facial wattles, which are particularly distinct in males. They also have very distinct tusks, which reach a length of in the males, but are always smaller in the females.Novak, R. M. (editor) (1999). ''Walker's Mammals of the World.'' Vol. 2. 6th edition. Johns Hopk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walrus
The walrus (''Odobenus rosmarus'') is a large pinniped, flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the family (biology), family Odobenidae and genus ''Odobenus''. This species is subdivided into two subspecies: the Atlantic walrus (''O. r. rosmarus''), which lives in the Atlantic Ocean, and the Pacific walrus (''O. r. divergens''), which lives in the Pacific Ocean. Adult walrus are characterised by prominent tusks and whiskers, and their considerable bulk: adult males in the Pacific can weigh more than and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walruses live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic zone, benthic bivalvia, bivalve mollusks to eat. Walruses are relatively long-lived, social animals, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephant
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and the order Proboscidea. The order was formerly much more diverse during the Pleistocene, but most species became extinct during the Late Pleistocene epoch. Distinctive features of elephants include a long proboscis called a trunk, tusks, large ear flaps, pillar-like legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Elephants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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