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Orrorin Tugenensis
''Orrorin tugenensis'' is a postulated early species of Homininae, estimated at and discovered in 2000. It is not confirmed how ''Orrorin'' is related to modern humans. Its discovery was used to argue against the hypothesis that australopithecines are human ancestors, although this remains the most prevalent hypothesis of human evolution as of 2012. The name of genus ''Orrorin'' (plural ''Orroriek'') means "original man" in Tugen, and the name of the only classified species, ''O. tugenensis'', derives from Tugen Hills in Kenya, where the first fossil was found in 2000. As of 2007, 20 fossils of the species have been found. Fossils The 20 specimens found as of 2007 are believed to be from at least five individuals. They include: the posterior part of a mandible in two pieces; a symphysis and several isolated teeth; three fragments of femora; a partial humerus; a proximal phalanx; and a distal thumb phalanx. ''Orrorin'' had small teeth relative to its body size. Its dentiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Miocene
The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The evolution of life The gibbons (family Hylobatidae) and orangutans (genus ''Pongo'') are the first groups to split from the line leading to the hominins, including humans, then gorillas (genus ''Gorilla''), and finally, chimpanzees and bonobo The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the comm ...s (genus '' Pan''). The splitting date between hominin and chimpanzee lineages is placed by some between 4 to 8 million years ago, that is, during the Late Miocene. References External links GeoWhen Database - Late Miocene .03 03 * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesial
This is a list of definitions of commonly used terms of location and direction in dentistry. This set of terms provides orientation within the oral cavity, much as anatomical terms of location provide orientation throughout the body. Terms Combining of terms Most of the principal terms can be combined using their corresponding combining forms (such as ''mesio-'' for ''mesial'' and ''disto-'' for ''distal''). They provide names for directions (vectors) and axes; for example, the coronoapical axis is the long axis of a tooth. Such combining yields terms such as those in the following list. The abbreviations should be used only in restricted contexts, where they are explicitly defined and help avoid extensive repetition (for example, a journal article that uses the term "mesiodistal" dozens of times might use the abbreviation "MD"). The abbreviations are ambiguous: (1) they are not spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crete
Crete ( el, Κρήτη, translit=, Modern: , Ancient: ) is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and Corsica. Crete rests about south of the Greek mainland, and about southwest of Anatolia. Crete has an area of and a coastline of 1,046 km (650 mi). It bounds the southern border of the Aegean Sea, with the Sea of Crete (or North Cretan Sea) to the north and the Libyan Sea (or South Cretan Sea) to the south. Crete and a number of islands and islets that surround it constitute the Region of Crete ( el, Περιφέρεια Κρήτης, links=no), which is the southernmost of the 13 top-level administrative units of Greece, and the fifth most populous of Greece's regions. Its capital and largest city is Heraklion, on the north shore of the island. , the region had a population of 636,504. The Dodecanese are located to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daily Nation
The ''Daily Nation'' is the highest circulation Kenyan independent newspaper with 170,000 copies. History The ''Daily Nation'' was started in the year 1958 as a Swahili weekly called ''Taifa'' by the Englishman Charles Hayes. It was bought in 1959 by the Aga Khan, and became a daily newspaper, ''Taifa Leo'' (Swahili for "Nation Today"), in January 1960. An English language edition called ''Daily Nation'' was published on 3 October 1960, in a process organised by former editor of the British ''News Chronicle'', Michael Curtis. The publisher was East African Newspapers (Nation Series) Ltd, which later became the Nation Media Group with operations throughout the African Great Lakes region. The newspaper is published by Nation Media Group from its headquarters at Nation Centre on Kimathi Street in Nairobi. It also maintains a website, which hosts online editions of the daily and Sunday titles. Access is partially free and the site's daily hit rate is more than three million. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thumb
The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb is ''pollex'' (compare ''hallux'' for big toe), and the corresponding adjective for thumb is ''pollical''. Definition Thumb and fingers The English word ''finger'' has two senses, even in the context of appendages of a single typical human hand: # Any of the five terminal members of the hand. # Any of the four terminal members of the hand, other than the thumb Linguistically, it appears that the original sense was the first of these two: (also rendered as ) was, in the inferred Proto-Indo-European language, a suffixed form of (or ), which has given rise to many Indo-European-family words (tens of them defined in English dictionaries) that involve, or stem from, concepts of fiveness. The thumb shares the following with each of the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postcranium
Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated skeletal elements; these are referred to as ''postcrania''. There is some disagreement over whether the skull and skeleton belong to the same or different animals. One example is the case of a Cretaceous sauropod skull of ''Nemegtosaurus'' found in association with the postcranial skeleton ''Opisthocoelicaudia ''Opisthocoelicaudia'' is a genus of sauropod dinosaur of the Late Cretaceous Period discovered in the Gobi Desert of Mongolia. The type species is ''Opisthocoelicaudia skarzynskii''. A well-preserved skeleton lacking only the head and neck wa ...''. In paleoanthropological studies, reconstruction of relationship between various species/remains is considered to be better supported by cranial characters rather than postcranial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesser Trochanter
The lesser trochanter is a conical posteromedial bony projection of the femoral shaft. it serves as the principal insertion site of the iliopsoas muscle. Structure The lesser trochanter is a conical posteromedial projection of the shaft of the femur, projecting from the posteroinferior aspect of its junction with the femoral neck. The summit and anterior surface of the lesser trochanter are rough, whereas its posterior surface is smooth. From its apex three well-marked borders extend: * two of these are above ** a medial continuous with the lower border of the femur neck ** a lateral with the intertrochanteric crest * the inferior border is continuous with the middle division of the linea aspera Attachments The summit of the lesser trochanter gives insertion to the tendon of the psoas major muscle and the iliacus muscle; the lesser trochanter represents the principal attachment of the iliopsoas. Anatomical relations The intertrochanteric crest (which demarcates the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur Neck
The femoral neck (femur neck or neck of the femur) is a flattened pyramidal process of bone, connecting the femoral head with the femoral shaft, and forming with the latter a wide angle opening medialward. Structure The neck is flattened from before backward, contracted in the middle, and broader laterally than medially. The vertical diameter of the lateral half is increased by the obliquity of the lower edge, which slopes downward to join the body at the level of the lesser trochanter, so that it measures one-third more than the antero-posterior diameter. The medial half is smaller and of a more circular shape. The anterior surface of the neck is perforated by numerous vascular foramina. Along the upper part of the line of junction of the anterior surface with the head is a shallow groove, best marked in elderly subjects; this groove lodges the orbicular fibers of the capsule of the hip joint. The posterior surface is smooth, and is broader and more concave than the anter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur Head
The femoral head (femur head or head of the femur) is the highest part of the thigh bone (femur). It is supported by the femoral neck. Structure The head is globular and forms rather more than a hemisphere, is directed upward, medialward, and a little forward, the greater part of its convexity being above and in front. The femoral head's surface is smooth. It is coated with cartilage in the fresh state, except over an ovoid depression, the fovea capitis, which is situated a little below and behind the center of the femoral head, and gives attachment to the ligament of head of femur. The thickest region of the articular cartilage is at the centre of the femoral head, measuring up to 2.8 mm. The diameter of the femoral head is usually larger in men than in women. Fovea capitis The fovea capitis is a small, concave depression within the head of the femur that serves as an attachment point for the ligamentum teres (Saladin). It is slightly ovoid in shape and is oriented "superior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-canine Megadontia
Post-canine megadontia is a relative enlargement of the molars and premolars compared to the size of the incisors and canines. This phenomenon is seen in some early hominid ancestors such as ''Paranthropus aethiopicus.'' Archaeological evidence The evidence for post-canine megadontia comes from measuring post-canine tooth surface area of hominid specimens and comparing these measurements to other hominid species. ''Australopithecus'', dated to have lived 2 to 3 million years ago, is the earliest hominid genus to demonstrate post-canine enlargement, with average post-canine tooth area ranging from approximately 460mm2 and going all the way up to the largest tooth area, 756mm2, which is seen in ''Paranthropus boisei'' . After ''Australopithecus'', a trend of steady decline in post-canine size is observed, starting in the genus ''Homo'' and culminating with ''Homo sapiens'' which has an average post-canine tooth area of only 334mm2. Studies of premolar size in hominid species that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdontia
Microdontia is a condition in which one or more teeth appear smaller than normal. In the generalized form, all teeth are involved. In the localized form, only a few teeth are involved. The most common teeth affected are the upper lateral incisors and third molars. Teeth affected by microdontia may also have abnormal shape, and the abnormal size may affect the whole tooth, or only a part of the tooth. Definition Males tend to have larger teeth than females, and tooth size also varies by race. Abnormal tooth size is defined by some as when the dimensions are more than 2 standard deviations from the average. Microdontia is when the teeth are abnormally small, and macrodontia is when the teeth are abnormally large. Classification There are 3 types of microdontia: True generalized All the teeth are smaller than the normal size. True generalized microdontia is very rare, and occurs in pituitary dwarfism. Due to decreased levels of growth hormone the teeth fail to develop to a norma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canine Tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, or (in the context of the upper jaw) fangs, eye teeth, vampire teeth, or vampire fangs, are the relatively long, pointed teeth. They can appear more flattened however, causing them to resemble incisors and leading them to be called ''incisiform''. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Individuals of most species that develop them normally have four, two in the upper jaw and two in the lower, separated within each jaw by incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. The four canines in humans are the two maxillary canines and the two mandibular canines. Details There are generally four canine teeth: two in the upper (maxillary) and two in the lower (mandibular) arch. A canine is placed laterall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
