|
Phyllotis Xanthopygus
The yellow-rumped leaf-eared mouse (''Phyllotis xanthopygus'') otherwise known as the Patagonian leaf-eared mouse is a species of rodent in the family Cricetidae and order Rodentia. It is the most widespread member of the genus. Description ''Phyllotis xanthopygus'' is a predominantly greyish brown/sand-colored New World mouse that reaches around 55g in its adulthood. Its thick coat is typically lighter on its underside, most prominent posteriorly, exhibiting countershading that is typical for many small mammals as it aids in camouflage from predators. True to its name, the Patagonian leaf-eared mouse has broad triangular ears similar to other leaf-eared members that compose the genus Phyllotis. The pelage of ''Phyllotis xanthopygus'' is known to differ seasonally. This example of phenotypic plasticity contributes to its ability to camouflage in a dynamic, seasonal, environment. Blending in with the vegetation and rocky outcrops is an important characteristic as their primary pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Robert Waterhouse
George Robert Waterhouse (6 March 1810 – 21 January 1888) was an English natural history, naturalist. He was a keeper at the department of geology and later curator of the Zoological Society of London's museum. Early life George was born in Somers Town to James Edward Waterhouse and Mary Newman. His father was a solicitor's clerk and an amateur entomologist. He was the brother of Frederick George Waterhouse, who also became a zoologist. George went to school at Koekelberg, near Brussels. He returned to England in 1824 and worked as an apprentice to an architect. Part of the work was in designing the garden of Charles Knight in the Vale of Health, Hampstead and the ornamentation for St. Dunstan's Church. Natural history George became interested in entomology through his father and he founded the Entomological Society of London along with Frederick William Hope in 1833 with himself as honorary curator. He became its president in 1849–50. He wrote articles for Knight's ''P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpor
Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time a hibernator spends at low body temperature, lasting days to weeks, or it can refer to a period of low body temperature and metabolism lasting less than 24 hours, as in "daily torpor". Animals that undergo daily torpor include birds (even tiny hummingbirds, notably Cypselomorphae) and some mammals, including many marsupial species, rodent species (such as mice), and bats. During the active part of their day, such animals maintain normal body temperature and activity levels, but their metabolic rate and body temperature drop during a portion of the day (usually night) to conserve energy. Some animals seasonally go into long periods of inactivity, with reduced body temperature and metabolism, made up of multiple bouts of torpor. This is kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentin
Dentin () (American English) or dentine ( or ) (British English) ( la, substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by enamel on the crown and cementum on the root and surrounds the entire pulp. By volume, 45% of dentin consists of the mineral hydroxyapatite, 33% is organic material, and 22% is water. Yellow in appearance, it greatly affects the color of a tooth due to the translucency of enamel. Dentin, which is less mineralized and less brittle than enamel, is necessary for the support of enamel. Dentin rates approximately 3 on the Mohs scale of mineral hardness. There are two main characteristics which distinguish dentin from enamel: firstly, dentin forms throughout life; secondly, dentin is sensitive and can become hypersensitive to changes in temperature due to the sensory function of odontoblasts, especially when enamel recedes and dentin channels becom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diastema
A diastema (plural diastemata, from Greek διάστημα, space) is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars. More colloquially, the condition may be referred to as gap teeth or tooth gap. In humans, the term is most commonly applied to an open space between the upper incisors (front teeth). It happens when there is an unequal relationship between the size of the teeth and the jaw. Diastemata are common for children and can exist in adult teeth as well. In humans Causes 1. Oversized Labial Frenulum: Diastema is sometimes caused or exacerbated by the action of a labial frenulum (the tissue connecting the lip to the gum), causing high mucosal attachment and less attached keratinized tissue. This is more prone to recession or by tongue thrusting, which can push the teeth apart. 2. Periodontal Disease: Periodontal disease, also known as gum disease, can result in bone loss that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheek Teeth
Cheek teeth or post-canines comprise the molar and premolar teeth in mammals. Cheek teeth are multicuspidate (having many folds or tubercles). Mammals have multicuspidate molars (three in placentals, four in marsupials, in each jaw quadrant) and premolars situated between canines and molars whose shape and number varies considerably among particular groups. For example, many modern Carnivora possess carnassials, or secodont teeth. This scissor-like pairing of the last upper premolar and first lower molar is adapted for shearing meat. In contrast, the cheek teeth of deer and cattle are selenodont. Viewed from the side, these teeth have a series of triangular cusps or ridges, enabling the ruminants' sideways jaw motions to break down tough vegetable matter. Cheek teeth are sometimes separated from the incisors by a gap called a diastema. Cheek teeth in reptiles are much simpler as compared to mammals. Roles and significance Apart from helping grind the food to properly reduce th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisor are: * maxillary central incisor (upper jaw, closest to the center of the lips) * maxillary lateral incisor (upper jaw, beside the maxillary central incisor) * mandibular central incisor (lower jaw, closest to the center of the lips) * mandibular lateral incisor (lower jaw, beside the mandibular central incisor) Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development. Typically, the mandibular central incisors erupt first, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frugivore
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and nutritional composition of fruits. Frugivores can benefit or hinder fruit-producing plants by either dispersing or destroying their seeds through digestion. When both the fruit-producing plant and the frugivore benefit by fruit-eating behavior the interaction is a form of mutualism. Frugivore seed dispersal Seed dispersal is important for plants because it allows their progeny to move away from their parents over time. The advantages of seed dispersal may have led to the evolution of fleshy fruits, which entice animals to consume them and move the plant's seeds from place to place. While many fruit-producing plant species would not disperse far without frugivores, their seeds can usually germinate even if they fall to the ground directl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Predation
Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of plants as a main or exclusive food source,Hulme, P.E. and Benkman, C.W. (2002) "Granivory", pp. 132–154 in ''Plant animal Interactions: An Evolutionary Approach'', ed. C.M. Herrera and O. Pellmyr. Oxford: Blackwell. . in many cases leaving the seeds damaged and not viable. Granivores are found across many families of vertebrates (especially mammals and birds) as well as invertebrates (mainly insects); thus, seed predation occurs in virtually all terrestrial ecosystems. Seed predation is commonly divided into two distinctive temporal categories, pre-dispersal and post-dispersal predation, which affect the fitness of the parental plant and the dispersed offspring (the seed), respectively. Mitigating pre- and post-dispersal predation may involve different strategies. To counter seed predation, plants have evolved both physical defenses ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insectivore
A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were amphibians. When they evolved 400 million years ago, the first amphibians were piscivores, with numerous sharp conical teeth, much like a modern crocodile. The same tooth arrangement is however also suited for eating animals with exoskeletons, thus the ability to eat insects is an extension of piscivory. At one time, insectivorous mammals were scientifically classified in an order called Insectivora. This order is now abandoned, as not all insectivorous mammals are closely related. Most of the Insectivora taxa have been reclassified; those that have not yet been reclassified and found to be truly related to each other remain in the order Eulipotyphla. Although individually small, insects exist in enormous numbers. Insects make u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, which is more difficult to digest than animal prey. This flora is made up of cellulose-digesting protozoans or bacteria. Etymology Herbivore is the anglicized form of a modern Latin coinage, ''herbivora'', cited in Charles Lyell's 1830 ''Principles of Geology''.J.A. Simpson and E.S.C. Weiner, eds. (2000) ''The Oxford English Dictionary'', vol. 8, p. 155. Richard Owen employed the anglicized term in an 1854 work on fossil teeth and skeletons. ''Herbivora'' is derived from Latin ''herba' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllotis Xanthopygus Etc
''Phyllotis'' is a genus of rodent in the family Cricetidae. These mice are commonly confused with ''Auliscomys, Graomys'' and ''Loxodontomys.'' ''.'' In order to tell these genera apart, one must look at the tail. Species in the genus ''Phyllotis'' have a penicillate tip on their tail which is not present in the other two genera. Tails in the genus Phyllotis are also less than the length of its head and body combined whereas in ''Graomys'', tails are longer than the head and body combined . ''Phyllotis xanthopygus'' was found at the summit of Volcán Llullaillaco (6739 m), which is the highest altitude a mammal has yet been found in nature. It contains the following species: * Los Alisos leaf-eared mouse (''Phyllotis alisosiensis'') * Friendly leaf-eared mouse (''Phyllotis amicus'') * Andean leaf-eared mouse (''Phyllotis andium'') * Anita's leaf-eared mouse (''Phyllotis anitae'') * Buenos Aires leaf-eared mouse (''Phyllotis bonariensis'') * Capricorn leaf-eared mouse (''Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_grazing_-_20050809.jpg "Click for more on -> Herbivore")