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Enhydriodon Sivalensis Sketch Cranium
''Enhydriodon'' is an extinct genus of typically large otters that lived in what is now Kenya, Ethiopia, Uganda, Chad, South Africa, Pakistan, and India from the late Miocene up to early Pleistocene. The otter is thought to be a relative of modern-day sea otters. ''E. omoensis'' and ''E. dikikae'' are described as the largest mustelids to have ever existed, though only fragments of the genus have been found such as the skull, femur, and dental remains in Ethiopia. Multiple estimates put them at about while ''E. omoensis'' was described to be lion-sized, making them the largest mustelids described so far. Most species of the ''Enhydriodon'' genus are presumed to be semi-aquatic given most of the fossil isotope values being similar to fossilized semi-aquatic animals like hippopotamuses. The largest species, ''Enhydriodon omoensis'', however, was determined to be a terrestrial predator, capable of hunting herbivorous terrestrial prey. ''Enhydriodon'' is part of the bunodont ott ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustelid
The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in the suborder Caniformia of the order Carnivora. They comprise about 66 to 70 species in nine subfamilies. Variety Mustelids vary greatly in size and behaviour. The smaller variants of the least weasel can be under in length, while the giant otter of Amazonian South America can measure up to and sea otters can exceed in weight. Wolverines can crush bones as thick as the femur of a moose to get at the marrow, and have been seen attempting to drive bears away from their kills. The sea otter uses rocks to break open shellfish to eat. Martens are largely arboreal, while European badgers dig extensive tunnel networks, called setts. Only one mustelid has been domesticated; the ferret. Tayra are also kept as pets (although they requ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mamelon (dentistry)
A mamelon (from French ''mamelon'', "nipple") is one of three rounded protuberances which are present on the cutting edge of an incisor tooth when it first erupts through the gum. Mamelons' appearance can be smoothed by a dentist if they have not been worn down naturally by biting and eating foods. Mamelons are present on permanent central and lateral incisors. Mamelons are easiest to observe on the maxillary central incisor The maxillary central incisor is a human tooth in the front upper jaw, or maxilla, and is usually the most visible of all teeth in the mouth. It is located mesial (closer to the midline of the face) to the maxillary lateral incisor. As with all i ...s, and appear as three small prominences on the incisal edge of the tooth. Mamelons are ordinarily of no clinical importance. Usually they are worn off early in the life of the tooth. References Parts of tooth {{dentistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolar
The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth distal to the canines, preceded by deciduous molars. Morphology There is always one large buccal cusp, especially so in the mandibular first premolar. The lower second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar (tooth)
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies from individual to individual. Race can also affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all. The human mouth contains upper (maxillary) and lower (mandib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lutra
''Lutra'' is a genus of otters, one of seven in the subfamily Lutrinae. Taxonomy and evolution The genus includes these species: Extant species Extinct species *†''Lutra affinis'' *†''Lutra bressana '' *†''Lutra bravardi'' *†''Lutra castiglionis'' *†''Lutra euxena'' *†''Lutra fatimazohrae'' *†''Lutra franconica'' *†''Lutra palaeindica'' *†''Lutra simplicidens'' *†''Lutra trinacriae'' The genus most likely evolved in Asia during the late Pliocene epoch; the oldest fossil belonging to the genus is of the species ''L. palaeindica'', and dates from the late Pliocene. Habitat ''Lutra'' species are semiaquatic mammals, so they are well-adapted to both water and land. They prefer shallow, narrow areas of streams surrounded by mature trees and with rocks, especially where weirs reduce the flow of the water, as well as attract fishes. They seem to tolerate roads and residential and agricultural areas, but only moderate human interaction. They clearly avoid are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology (that is, the relationship between the shape and form of the tooth in question and its inferred function) of the teeth of an animal. Animals whose teeth are all of the same type, such as most non-mammalian vertebrates, are said to have '' homodont'' dentition, whereas those whose teeth differ morphologically are said to have '' heterodont'' dentition. The dentition of animals with two successions of teeth (deciduous, permanent) is referred to as ''diphyodont'', while the dentition of animals with only one set of teeth throughout life is ''monophyodont''. The dentition of animals in which the teeth are continuously discarded and replaced throughout life is termed ''polyphyodont''. The dentition of animals in which the teeth are set in so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine. Dia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siwalik Hills
The Sivalik Hills, also known as the Shivalik Hills and Churia Hills, are a mountain range of the outer Himalayas that stretches over about from the Indus River eastwards close to the Brahmaputra River, spanning the northern parts of the Indian subcontinent. It is wide with an average elevation of . Between the Teesta and Raidāk Rivers in Assam is a gap of about . "Sivalik" literally means 'tresses of Shiva'. Sivalik region is home to the Soanian archaeological culture. Geology Geologically, the Sivalik Hills belong to the Tertiary deposits of the outer Himalayas. They are chiefly composed of sandstone and conglomerate rock formations, which are the solidified detritus of the Himalayas to their north; they are poorly consolidated. The remnant magnetisation of siltstones and sandstones indicates that they were deposited 16–5.2 million years ago. In Nepal, the Karnali River exposes the oldest part of the Shivalik Hills. They are bounded on the south by a fault system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhydriodon Sivalensis Sketch Cranium
''Enhydriodon'' is an extinct genus of typically large otters that lived in what is now Kenya, Ethiopia, Uganda, Chad, South Africa, Pakistan, and India from the late Miocene up to early Pleistocene. The otter is thought to be a relative of modern-day sea otters. ''E. omoensis'' and ''E. dikikae'' are described as the largest mustelids to have ever existed, though only fragments of the genus have been found such as the skull, femur, and dental remains in Ethiopia. Multiple estimates put them at about while ''E. omoensis'' was described to be lion-sized, making them the largest mustelids described so far. Most species of the ''Enhydriodon'' genus are presumed to be semi-aquatic given most of the fossil isotope values being similar to fossilized semi-aquatic animals like hippopotamuses. The largest species, ''Enhydriodon omoensis'', however, was determined to be a terrestrial predator, capable of hunting herbivorous terrestrial prey. ''Enhydriodon'' is part of the bunodont ott ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhydra
''Enhydra'' is a genus of mustelid that contains the sea otter and two extinct relatives. It is the only extant genus of the bunodont otters group, referring to otters with non-blade carnassials with rounded cusps. Sea otters probably diverged from other otters during the Pliocene, approximately 5 mya. They probably arose from the closely related ''Enhydritherium'', a bunodont otter endemic to North America during the late Miocene and early Pliocene epochs. ''Enhydra reevei'', the oldest known species, has its origins in the Atlantic, suggesting this may have been where sea otters originated. Fossil evidence indicates the ''Enhydra'' lineage became isolated in the North Pacific approximately 2 million years ago, giving rise to the now-extinct ''Enhydra macrodonta ''Enhydra macrodonta'', the large-toothed sea otter, is an extinct mustelid known from the middle Pleistocene in California California is a state in the Western United States, located along the Pacific Coast. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnassial
Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified fourth upper premolar and the first lower molar, however this may vary in family. These teeth are also referred to as sectorial teeth. Taxonomy The name carnivoran is applied to a member of the order Carnivora. Carnivorans possess a common arrangement of teeth called carnassials, in which the first lower molar and the last upper premolar possess blade-like enamel crowns that act similar to a pair of shears for cutting meat. This dental arrangement has been modified by adaptation over the past 60 million years for diets composed of meat, for crushing vegetation, or for the loss of the carnassial function altogether as in seals, sea lions, and walruses. Carnassial dentition Carnassial teeth are modified molars (and in the case of carn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
