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Zygomatic Notch
In rodent anatomy, the zygomatic plate is a bony plate derived from the flattened front part of the zygomatic arch (cheekbone). At the back, it connects to the front (maxillary) root of the zygomatic arch, and at the top it is connected to the rest of the skull via the ''antorbital bridge''.Steppan, 1995, p. 29 It is part of the maxillary bone, or upper jaw, which also contains the upper cheekteeth. Primitively, rodents have a nearly horizontal zygomatic plate.Wood, 1935, p. 246 In association with specializations in zygomasseteric system, several distinct morphologies have developed across the order. The term is also used for an analogous structure in some South American typotheres, including '' Pseudotypotherium'' and '' Medistylus''. Function The zygomatic plate serves to resist muscular tension resulting from the contraction of the incisors by the anterior deep masseter muscle; thus, rodents which pulverize hard food with the incisors tend to have broader zygom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rattus Macleari Skull Zygomatic Plate
''Rattus'' is a genus of muroid rodents, all typically called rats. However, the term rat can also be applied to rodent species outside of this genus. Species and description The best-known ''Rattus'' species are the black rat (''R. rattus'') and the brown rat (''R. norvegicus''). The group is generally known as the Old World rats or true rats and originated in Asia. Rats are bigger than most Old World mouse, mice, which are their relatives, but seldom weigh over in the wild. Taxonomy of ''Rattus'' The genus ''Rattus'' is a member of the giant subfamily Murinae. Several other murine genera are sometimes considered part of ''Rattus'': ''Lenothrix'', ''Anonymomys'', ''Sundamys'', ''Kadarsanomys'', ''Diplothrix'', ''Margaretamys'', ''Lenomys'', ''Komodomys'', ''Palawanomys'', ''Bunomys'', ''Nesoromys'', ''Stenomys'', ''Taeromys'', ''Paruromys'', ''Abditomys'', ''Tryphomys'', ''Limnomys'', ''Tarsomys'', ''Bullimus'', ''Apomys'', ''Millardia'', ''Srilankamys'', ''Niviventer'', ''Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaver
Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-largest living rodents, after capybaras, weighing up to . They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet, and tails that are flat and scaly. The two species differ in skull and tail shape and fur color. Beavers can be found in a number of freshwater habitats, such as rivers, streams, lakes and ponds. They are herbivorous, consuming tree bark, aquatic plants, grasses and sedges. Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they chew down trees for building material. Dams restrict water flow, forming ponds, and lodges (usually built in ponds) serve as shelters. Their infrastructure creates wetlands used by many other species, a ... [...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 phylogenetic 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossorial
A fossorial animal () is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are Mole (animal), moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamanders. Among invertebrates, many molluscs (e.g., clams), insects (e.g., beetles, wasps, bees), and arachnids (e.g. spiders) are fossorial. Prehistoric evidence The physical adaptation of fossoriality is widely accepted as being widespread among many Prehistory, prehistoric Phylum, phyla and Taxon, taxa, such as bacteria and early eukaryotes. Furthermore, fossoriality has evolved independently multiple times, even within a single Family (biology), family. Fossorial animals appeared simultaneously with the colonization of land by arthropods in the late Ordovician period (over 440 million years ago). Other notable early burrowers include ''Eocaecilia'' and possibly ''Dinilysia''. The oldest example of burrowing in synapsids, the lineag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platacanthomyidae
The rodent family Platacanthomyidae, or Oriental dormice, includes the Platacanthomys, spiny dormice and the Typhlomys, Chinese pygmy dormice. In spite of their appearance, these animals are not true dormouse, dormice, but are part of the large and complex Taxonomic rank, superfamily Muroidea. The platacanthomyids can be distinguished from the true dormice, because they have no premolars, giving them three cheek teeth, like their relatives, the Muroidea. The evolutionary relationship of the Platacanthomyidae was uncertain until a molecular phylogenetic study found it to be the earliest extant lineage to branch within the superfamily Muroidea. They can be distinguished from both the family Spalacidae and the Eumuroida (all non-spalacid and non-platacanthomyid muroids), by the distinct shape of their infraorbital canal and by the presence of multiple Foramina of the skull, openings in the palate of the skull. On the basis of these two characteristics, they have been considered to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipodidae
Jerboas () are the members of the family Dipodidae. They are hopping desert rodents found throughout North Africa and Asia. They tend to live in hot deserts. When chased, jerboas can run at up to . Some species are preyed on by little owls (''Athene noctua'') in central Asia. Most species of jerboas have excellent hearing that they use to avoid becoming the prey of nocturnal predators. The typical lifespan of a jerboa is around 2–3 years. Taxonomy Jerboas, as previously defined, were thought to be paraphyletic, with the jumping mice ( Zapodidae) and birch mice (Sminthidae) also being classified in the family Dipodidae. However, phylogenetic analysis split all three as distinct families, leaving just the jerboas in Dipodidae and revealing them to be a monophyletic group. This animal has a body length (including the head) of between , with an additional of tail, which is always longer than the full body. Jerboa dental records reveal a slow increase in crown heights, which c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process (anatomy)
In anatomy, a process () is a projection or outgrowth of tissue from a larger body. For instance, in a vertebra, a process may serve for muscle attachment and leverage (as in the case of the transverse and spinous processes), or to fit (forming a synovial joint A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulati ...), with another vertebra (as in the case of the articular processes).Moore, Keith L. et al. (2010) ''Clinically Oriented Anatomy'', 6th Ed, p.442 fig. 4.2 The word is also used at the microanatomic level, where cells can have processes such as cilia or pedicels. Depending on the tissue, processes may also be called by other terms, such as ''apophysis'', '' tubercle'', or ''protuberance''. Examples Examples of processes include: *The many processes of the human skull: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muroidea
The Muroidea are a large Taxonomic rank, superfamily of rodents, including mice, rats, voles, hamsters, lemmings, Gerbillinae, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitat (ecology), 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 subfamily, 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 (biology), taxonomy is based on recent well-supported molecular phylogeny, molecular phylogenies. The muroids are classified in six family (biology), f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springhaas
''Pedetes'' is a genus of rodent, the springhares, in the family Pedetidae. Members of the genus are distributed across southern and Eastern Africa. Species A number of species both extant and extinct are classified in the genus ''Pedetes''. They include: * South African springhare or ''springhaas'' (''Pedetes capensis'') * East African springhare (''Pedetes surdaster'') * ''Pedetes laetoliensis'' (Davies, 1987) (Pliocene fossil) Throughout the 20th century, the living species (and occasionally the prehistoric one) were merged into ''P. capensis'', making the genus monotypic. Ecology These rodents are generally nocturnal and sleep through the day in burrows they dig. They feed on foliage, roots and other vegetable matter, and occasionally arthropods. Outside the burrow they usually move around by hopping on their hind legs. When only one springhare species was recognized, it was listed as vulnerable by the IUCN in 1996 due to an approximately 20% decrease in the population o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
