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Myomorpha
The suborder Myomorpha contains 1,524 species of mouse-like rodents, nearly a quarter of all mammal species. Included are mice, rats, gerbils, hamsters, lemmings, and voles. They are grouped according to the structure of their jaws and molar teeth. They are characterized by their myomorphous zygomasseteric system, which means that both their medial and lateral masseter muscles are displaced forward, making them adept at gnawing. As in the hystricognathous rodents, the medial masseter muscle goes through the eye socket, a feature unique among mammals. Myomorphs are found worldwide (apart from Antarctica) in almost all land habitats. They are usually nocturnal seed-eaters. Most myomorph species belong to the superfamily Muroidea: (hamsters, voles, lemmings, true mice, true rats, and gerbils). *Superfamily Muroidea **Family Platacanthomyidae ( spiny dormice and Chinese pygmy dormice) **Family Spalacidae ( blind mole-rats and bamboo rats) **Family Calomyscidae (mouse-like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygomasseteric System
The zygomasseteric system (or zygomasseteric structure) in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal (front-to-back) motion of the rodent jaw is enabled by an extension of the zygomatic arch and the division of the masseter into a superficial, lateral and medial muscle. The four main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous.{* Protrogomorphy The members of this grade include nearly all of the pre-Oligocene rodents of North America and Asia and some of those of Europe. Several lineages survive into the Oligocene or early Miocene, with only one species still alive today, the mountain beaver ('' Aplodontia rufa''). The molerats (family Bathyergidae) are considered secondarily protrogomorphous since their zygomatic condition is clearly derived from a hystricomorphous ancestor. The rostrum of protrogomorph rodents is unmodified an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouse
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus''). Mice are also popular as pets. In some places, certain kinds of field mice are locally common. They are known to invade homes for food and shelter. Mice are typically distinguished from rats by their size. Generally, when a muroid rodent is discovered, its common name includes the term ''mouse'' if it is smaller, or ''rat'' if it is larger. The common terms ''rat'' and ''mouse'' are not taxonomically specific. Typical mice are classified in the genus '' Mus'', but the term ''mouse'' is not confined to members of ''Mus'' and can also apply to species from other genera such as the deer mouse, ''Peromyscus''. Domestic mice sold as pets often differ substantially in size from the common house mouse. This is attributable to breeding a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muridae
The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. The name Muridae comes from the Latin ' (genitive '), meaning "mouse", since all true mice belong to the family, with the more typical mice belonging to the genus '' Mus''. Distribution and habitat Murids are found nearly everywhere in the world, though many subfamilies have narrower ranges. Murids are not found in Antarctica or many oceanic islands. Although none of them are native to the Americas, a few species, notably the house mouse and black rat, have been introduced worldwide. Murids occupy a broad range of ecosystems from tropical forests to tundras. Fossorial, arboreal, and semiaquatic murid species occur, though most are terrestrial animals. The extensive list of niches filled by murids helps to explain their relative abundance. Diet and dentiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muroidea
The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to difficulties in determining how the subfamilies are related to one another. Many of the families within the Muroidea superfamily have more variations between the families than between the different clades. A possible explanation for the variations in rodents is because of the location of these rodents; these changes could have been due to radiation or the overall environment they migrated to or originated in. The following taxonomy is based on recent well-supported molecular phylogenies. The muroids are classified in six families, 19 subfamilies, around 280 genera, and at least 1,750 species. Taxonomy *Family Platacanthomyidae (spiny ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calomyscidae
200px, right 200px, Mouse-like hamster using its tail for balance while standing on a branch (a feat difficult for hamsters) Mouse-like hamsters are a group of small rodents found in Syria, Azerbaijan, Iran, Turkmenistan, Afghanistan, and Pakistan. They are found in rocky outcrops and semi-mountainous areas in desert regions. The mouse-like hamsters are not true hamsters, but represent an early split from the rest of the mouse-like rodents. They were once thought to be hamsters based on the shape of their molars, but they lack the cheek pouches, flank glands and short tails of the true hamsters. The closest relatives of the mouse-like hamsters may be the extinct Cricetodontidae. Because of their seemingly early break from the rest of the mouse-like rodents, mouse-like hamsters have been placed in a family of their own, Calomyscidae, and have been referred to as living fossils. All members of the genus were once considered part of the same species, ''Calomyscus bailwardi'', b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spalacidae
The Spalacidae, or spalacids, are a family of rodents in the large and complex superfamily Muroidea. They are native to eastern Asia, the Horn of Africa, the Middle East, and southeastern Europe. It includes the blind mole-rats, bamboo rats, mole-rats, and zokors. This family represents the oldest split (excluding perhaps the Platacanthomyidae) in the muroid superfamily, and comprises animals adapted to a subterranean way of life. These rodents were thought to have evolved adaptations to living underground independently until recent genetic studies demonstrated they form a monophyletic group. Members of the Spalacidae are often placed in the family Muridae along with all other members of the Muroidea. Characteristics Spalacids are mouse- to rat-sized rodents, adapted to burrowing and living underground. They have short limbs, wedge-shaped skulls, strong neck muscles, large incisor teeth, and small eyes and external ears. In the zokors, which dig primarily with their feet, rat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spalax
''Spalax'' is a genus of rodent in the family Spalacidae, subfamily ''Spalacinae'' (blind mole-rats). It is one of two extant genera in the subfamily Spalacinae, alongside ''Nannospalax''.'''' Species in this genus are found in eastern Europe and western & central Asia. They are completely blind and have a subterranean lifestyle. Taxonomy Prior to 2013, ''Spalax'' was widely considered the only member of Spalacinae, with all blind mole-rat species being grouped within it. However, phylogenetic and morphological evidence supported some of the species within it forming a distinct lineage that diverged from the others during the Late Miocene, when a marine barrier formed between Anatolia and the Balkans. These species were reclassified into the genus ''Nannospalax'', making ''Spalax'' one of two extant spalacine genera.'''' Species of genus ''Spalax'' *Mehely's blind mole-rat'', S. antiquus'' * Sandy blind mole-rat, ''S. arenarius'' * Giant blind mole-rat, ''S. giganteus'' *B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamboo Rats
The bamboo rats are four species of rodents of the subfamily Rhizomyinae. They are the sole living representatives of the tribe Rhizomyini. All are found in South Asia, Southeast Asia and East Asia. The species are: *The Chinese bamboo rat, ''Rhizomys sinensis'', found in central and southern China, northern Burma, and Vietnam; *The hoary bamboo rat, '' R. pruinosus'', found from Assam in India to southeastern China and the Malay Peninsula; *The Sumatra, Indomalayan, or large bamboo rat, ''R. sumatrensis'', found in Yunnan in China, Indochina, the Malay Peninsula and Sumatra. *The lesser bamboo rat, '' Cannomys badius'', found in Nepal, Assam, northern Bangladesh, Burma, Thailand, Laos, Cambodia and northern Vietnam. Bamboo rats vary in size, from the lesser bamboo rat, which is typically long (head and body: tail length is ), and weighs from , to the Sumatra bamboo rat, which can reach lengths of nearly with a tail, and weighs up to . However, they are all bulky, slow-mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ypresian
In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgium, Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flanders, Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouse-like Hamsters
200px, right 200px, Mouse-like hamster using its tail for balance while standing on a branch (a feat difficult for hamsters) Mouse-like hamsters are a group of small rodents found in Syria, Azerbaijan, Iran, Turkmenistan, Afghanistan, and Pakistan. They are found in rocky outcrops and semi-mountainous areas in desert regions. The mouse-like hamsters are not true hamsters, but represent an early split from the rest of the mouse-like rodents. They were once thought to be hamsters based on the shape of their molars, but they lack the cheek pouches, flank glands and short tails of the true hamsters. The closest relatives of the mouse-like hamsters may be the extinct Cricetodontidae. Because of their seemingly early break from the rest of the mouse-like rodents, mouse-like hamsters have been placed in a family of their own, Calomyscidae, and have been referred to as living fossils. All members of the genus were once considered part of the same species, ''Calomyscus bailwardi'', b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesomyidae
The Nesomyidae are a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are Malagasy rodents, climbing mice, African rock mice, swamp mice, pouched rats, and the white-tailed rat. Characteristics Nesomyids are small- to medium-sized rodents, with the largest being the size of a rat. Physically, they may resemble mice, rats, voles, or hamsters, depending on the species and subfamily. Their diets vary from fairly strict herbivory to nearly pure insectivory. Their habits are similarly variable, with some species climbing trees, and others burrowing in the ground. They give birth to up to four young after a gestation period around six weeks. Classification Many of these animals were once thought to be related to other groups of muroid rodents, but this African-based clade has been proposed and confirmed on the basis of genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
