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Microgale Macpheei
''Microgale macpheei'' is an extinct shrew tenrec from southeastern Madagascar. It is known only from two partial skulls found in Andrahomana cave, which radiocarbon dating of associated rodent remains suggests are about 3000 years old. It is the only known recently extinct tenrec. First described in 2007, it is most similar to the smaller '' Microgale brevicaudata'' of northern and western Madagascar. ''M. macpheei'' has a broad rostrum (front part of the skull) and, like ''M. brevicaudata'', lacks a diastema (gap) between the premolars. A number of details of tooth morphology are characteristic of ''M. macpheei''. Taxonomy Remains of shrew tenrecs (''Microgale'') were found during expeditions to the cave of Andrahomana in southeastern Madagascar, led by David Burney in 2000 and 2003.Goodman et al., 2007, p. 368 The ''Microgale'' material was described as a new species, ''M. macpheei'', in 2007 by Steven Goodman, Natalie Vasey, and Burney.Goodman et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Replacement
Tooth loss is a process in which one or more teeth come loose and fall out. Tooth loss is normal for deciduous teeth (baby teeth), when they are replaced by a person's adult teeth. Otherwise, losing teeth is undesirable and is the result of injury or disease, such as dental avulsion, tooth decay, and gum disease. The condition of being toothless or missing one or more teeth is called ''edentulism''. Tooth loss has been shown to causally reduce overall health and wellbeing as it increases the probability of depression. Tooth exfoliation in children Normal loss of primary teeth typically begins around age six and continues until age twelve. The upper and lower central incisors are shed at age six to seven years. The upper and lower lateral incisors are shed at seven to eight years. The upper canines are shed at ten to twelve years. The lower canines are shed at nine to twelve years. The upper and lower first molars are shed at nine to eleven years. The upper and lower sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrotarsomys Petteri
Petter's big-footed mouse (''Macrotarsomys petteri''), is a Madagascan rodent in the genus '' Macrotarsomys''. With a head and body length of 150 mm (5.9 in) and body mass of 105 g (3.7 oz), it is the largest species of its genus. Its upper body is brown, darkest in the middle of the back, and the lower body is white to yellowish. The animal has long whiskers, short forelimbs, and long hindfeet. The tail ends in a prominent tuft of long, light hairs. The skull is robust and the molars are low-crowned and cuspidate. Petter's big-footed mouse is now found only in the Mikea Forest of southwestern Madagascar, but subfossil records indicate that it used to be more widely distributed in southern Madagascar. Climatic changes and competition with introduced species may have led to the shift in its distribution. The Mikea Forest, the only place where it is still known to occur, is threatened by human development. Taxonomy During a 2003 biological inventory of the Mike ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesic Habitat
In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Mesic habitats transition to xeric shrublands in a non-linear fashion, which is evidence of a threshold. Mesic is one of a triad of terms used to describe the amount of water in a habitat. The others are xeric and hydric. Further examples of mesic habitats include streamsides, wet meadows, springs, seeps, irrigated fields, and high elevation habitats. These habitats effectively provide drought insurance as land at higher elevations warms due to seasonal or other change. Healthy mesic habitats act like sponges in that they store water in such a way that it can be deposited to neighboring habitats as needed. They are common in dryer regions of the western United States, and can be a good water source to neighboring desert habitats. Healthy mesic habitats also provide forb and insects for organisms belonging t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypogeomys Australis
''Hypogeomys australis'' is an extinct rodent from central and southeastern Madagascar. First described in 1903, it is larger than its close relative, the living '' Hypogeomys antimena'', which occurs further west, but otherwise similar. Average length of the femur (upper leg bone) is 72.1 mm, compared to 63.8 mm in ''H. antimena''. One of the few extinct rodents of Madagascar, it survived to at least around 1536 BP based on radiocarbon dating. Little is known of its ecology, but it may have lived in burrows like its living relative and eaten some arid-adapted plants. Taxonomy ''Hypogeomys australis'' was described in 1903 by Guillaume Grandidier from subfossil material collected in the cave of Andrahomana in southeastern Madagascar. The ''Hypogeomys'' material was similar to the living '' Hypogeomys antimena'', but distinct enough for Grandidier to recognize it as a separate species, different in size and some morphological details. Grandidier described anot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracone
A paracone is a 1960s atmospheric reentry or spaceflight mission abort concept using an inflatable ballistic cone.Analysis and design of space vehicle flight control systems, Volume 16: Abort by A.L. Greensite, '''', 1969, accessed 2010-05-25. A notable feature of the paracone concept is that it facilitates an abort throughout the entire profile. Gallery [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocone
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. Buccal Cusp- One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is no ... [...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] |
