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Dentition Types
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. Terminology 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Jaw Dentition
Upper may refer to: * Shoe upper or ''vamp'', the part of a shoe on the top of the foot * Stimulant, drugs which induce temporary improvements in either mental or physical function or both * ''Upper'', the original film title for the 2013 found footage film ''The Upper Footage'' * Dmitri Upper Dmitri Sergeyevich Upper (; born July 27, 1978) is a Kazakhstani former professional ice hockey center. He also holds Russian citizenship. Career Upper was selected by the New York Islanders in the 5th round (136th overall) of the 2000 NHL ... (born 1978), Kazakhstani ice hockey player See also * Uppers (video game), a video game by Marvelous {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolar
The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in the permanent teeth, permanent set of teeth, making eight premolars total in the mouth. They have at least two Cusp (dentistry), 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 (anatomy), 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 Anatomical terms of location#Proximal and distal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Chimpanzee
The chimpanzee (; ''Pan troglodytes''), also simply known as the chimp, is a species of great ape native to the forests and savannahs of tropical Africa. It has four confirmed subspecies and a fifth proposed one. When its close relative the bonobo was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus ''Pan''. Evidence from fossils and DNA sequencing shows that ''Pan'' is a sister taxon to the human lineage and is thus humans' closest living relative. The chimpanzee is covered in coarse black hair but has a bare face, fingers, toes, palms of the hands, and soles of the feet. It is larger and more robust than the bonobo, weighing for males and for females and standing . The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macaque
The macaques () constitute a genus (''Macaca'') of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and Europe (in Gibraltar). Macaques are principally frugivorous (preferring fruit), although their diet also includes seeds, leaves, flowers, and tree bark. Some species such as the long-tailed macaque (''M. fascicularis''; also called the crab-eating macaque) will supplement their diets with small amounts of meat from shellfish, insects, and small mammals. On average, a southern pig-tailed macaque (''M. nemestrina'') in Malaysia eats about 70 large rats each year. All macaque social groups are arranged around dominant matriarchs. Macaques are found in a variety of habitats throughout the Asian continent and are highly adaptable. Certain species are synanthropic, having learned to live alongside humans, but they have become problematic in urban areas in Southeast Asia and are not suitabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyrrhine
New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboidea (), the only extant superfamily in the parvorder Platyrrhini (). Platyrrhini is derived from the Greek for "broad nosed", and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey, are the only primates to have prehensile tails. New World monkeys' closest relatives are the other simians, the Catarrhini ("down-nosed"), comprising Old World monkeys and apes. New World monkeys descend from African simians that colonized South America, a line that split off about 40 million years ago. Evolutionary history About 40 million years ago, the Simiiformes infraorder split into the parvorders Platyrrhini (New World monkeys) and Catarrhini (apes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosimian
Prosimians are a group of primates that includes all living and extinct Strepsirrhini, strepsirrhines (lemurs, Lorisoidea, lorisoids, and Adapiformes, adapiforms), as well as the Haplorhini, haplorhine tarsiers and their extinct relatives, the Omomyidae, omomyiforms, i.e. all primates excluding the simians. They are considered to have characteristics that are more "Primitive (biology), primitive" (ancestral or Cladistics#Terminology for character states, plesiomorphic) than those of simians (monkeys, apes, and humans). Simians emerged within the Prosimians as sister group of the Haplorhini, haplorhine tarsiers, and therefore Cladistics, cladistically belong to this group. Simians are thus distinctly closer related to tarsiers than lemurs are. Strepsirrhines bifurcated some 20 million years earlier than the tarsier - simian bifurcation. However, simians are traditionally excluded, rendering prosimians paraphyletic. Consequently, the term "prosimian" is no longer widely used in a ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wisdom Tooth
The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs between late teens and early twenties. Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck ( impacted) and not erupt fully, if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is disputed. Impacted wisdom teeth may suffer from tooth decay if oral hygiene becomes more difficult. Wisdom teeth which are partially erupted through the gum may also cause inflammation and infection in the surrounding gum tissues, termed pericoronitis. More conservativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing#Evolution of hairlessness, hairlessness, bipedality, bipedalism, and high Human intelligence, intelligence. Humans have large Human brain, brains, enabling more advanced cognitive skills that facilitate successful adaptation to varied environments, development of sophisticated tools, and formation of complex social structures and civilizations. Humans are Sociality, highly social, with individual humans tending to belong to a Level of analysis, multi-layered network of distinct social groups — from families and peer groups to corporations and State (polity), political states. As such, social interactions between humans have established a wide variety of Value theory, values, norm (sociology), social norms, languages, and traditions (co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aye-aye
The aye-aye (''Daubentonia madagascariensis'') is a long-fingered lemur, a Strepsirrhini, strepsirrhine primate native to Madagascar with rodent-like teeth that perpetually grow and a special thin middle finger that they can use to catch grubs and larvae out of tree trunks. It is the world's largest Nocturnality, nocturnal primate. It is characterized by its unusual method of finding food: it taps on trees to find Larva, grubs, then gnaws holes in the wood using its forward-slanting incisors to create a small hole into which it inserts its narrow middle finger to pull the grubs out. This foraging method is called ''percussive foraging'', and takes up 5–41% of foraging time. The only other living mammal species known to find food in this way are the striped possum and trioks (genus ''Dactylopsila'') of northern Australia and New Guinea, which are marsupials. From an ecological point of view, the aye-aye fills the niche of a woodpecker, as it is capable of penetrating wood to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus (biology), fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer, considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less-developed young, which are then nurtured for a period inside the mother's pouch (marsupial), pouch. Placentalia represents the only living group within Eutheria, which contains all mammals that are more closely related to placentals than they are to marsupials. Anatomical features Placental mammals are anatomically distinguished from other mammals by: * a sufficiently wide opening at the bottom of the pelvis to allow the birt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catarrhini
The parvorder Catarrhini (known commonly as catarrhine monkeys, Old World anthropoids, or Old World monkeys) consists of the Cercopithecoidea and apes (Hominoidea). In 1812, Geoffroy grouped those two groups together and established the name Catarrhini, "Old World monkeys", ("''singes de l'Ancien Monde''" in French). Its sister in the infraorder Simiiformes is the parvorder Platyrrhini (New World monkeys). There has been some resistance to directly designate apes (and thus humans) as monkeys despite the scientific evidence, so "Old World monkey" may be taken to mean the Cercopithecoidea or the Catarrhini. That apes are monkeys was already realized by Georges-Louis Leclerc, Comte de Buffon in the 18th century. Linnaeus placed this group in 1758 together with what we now recognise as the tarsiers and the New World monkeys, in a single genus "'' Simia''" (sans ''Homo''). The Catarrhini are all native to Africa and Asia. Members of this parvorder are called catarrhines. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circular Sector
A circular sector, also known as circle sector or disk sector or simply a sector (symbol: ⌔), is the portion of a disk (a closed region bounded by a circle) enclosed by two radii and an arc, with the smaller area being known as the ''minor sector'' and the larger being the ''major sector''. In the diagram, is the central angle, the radius of the circle, and is the arc length of the minor sector. The angle formed by connecting the endpoints of the arc to any point on the circumference that is not in the sector is equal to half the central angle. Types A sector with the central angle of 180° is called a '' half-disk'' and is bounded by a diameter and a semicircle. Sectors with other central angles are sometimes given special names, such as quadrants (90°), sextants (60°), and octants (45°), which come from the sector being one quarter, sixth or eighth part of a full circle, respectively. Area The total area of a circle is . The area of the sector can be obtai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
