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Geomyoidea
Geomyoidea is a superfamily of rodent that contains the pocket gophers ( Geomyidae), the kangaroo rats and mice ( Heteromyidae), and their fossil relatives. Characteristics Although dissimilar in overall appearance, gophers have been united with kangaroo rats into a common superfamily for a considerable time. The superfamily Geomyoidea is among the few superfamilial relationships in rodents that is not subject to much controversy. Overall morphology, the fossil record, molecular analyses, and biogeography all support this relationship. Geomyoids are most noticeably characterized by the position of the infraorbital canal. Unlike all other rodents who have the opening of the infraorbital canal facing forward, geomyoids have an infraorbital canal that faces to the side. Instead of passing through the zygoma, the infraorbital canal of geomyoids has moved to the side of the snout. This condition is so pronounced and the snout so narrow in heteromyids that the infraorbital c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliscomyidae
Heliscomyidae is a family of extinct rodents from the mid-Tertiary of North America related to pocket gophers (family Geomyidae) and kangaroo rats and their relatives (family Heteromyidae). The family contains four genera, '' Apletotomeus'', '' Heliscomys'', '' Passaliscomys'', and '' Tylionomys'' (Korth et al., 1991; Korth and Eaton, 2004; Korth and Branciforte, 2007). McKenna and Bell (1997) placed the first two genera in synonymy, with ''Heliscomys'' as the senior synonym. Characteristics Heliscomyids are distinguished from other geomyoid rodents by several characteristics of the skull including the fusion of three cranial foramina, elongation of the incisive foramina, and an unusual position of the mental foramen (Korth et al., 1991). Taxonomy Heliscomyidae is a member of the clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for 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/ricochetal (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 Mouse, mice, rats, squirrels, prairie dogs, porcupines, beavers, Cavia, guinea pigs, and hamsters. Once included wi ... [...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] |
Sciuromorphous
The zygomasseteric system (or zygomasseteric structure) refers to the anatomical arrangement of the masseter muscle and the zygomatic arch (cheek bone) in the skulls of rodents. This system plays a crucial role in the diverse chewing mechanics observed across rodent species. The zygomatic arch is modified to accommodate the masseter muscle, a primary muscle responsible for jaw movement. The masseter muscle itself is often divided into superficial, lateral, and medial components, allowing for a wide range of jaw motion, particularly the anteroposterior or propalinal movement (front-to-back chewing motion) characteristic of rodents. Variations in the structure of the zygomatic arch and the masseter muscle's insertion points have led to the classification of rodents into four main zygomasseteric types: protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous, reflecting adaptations to different dietary niches and chewing strategies. Protrogomorphy The members of thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomorpha (bug)
''Geomorpha'' is a genus of African bugs in the subfamily Pentatominae Pentatominae is a subfamily of Pentatomidae, a family of shield bugs. This subfamily is the largest one within the Pentatomidae, having 4937 species classified in 938 genera. Species in this subfamily are phytophages and several of them are consid ... (tribe Aeschrocorini), erected by Ernst Evald Bergroth in 1893.Bergroth EE (1893) ''J. Acad. Lisboa'', (2) 3. Species BioLib lists: # '' Geomorpha junodi'' Distant, 1904 # '' Geomorpha lujai'' Schouteden, 1917 # '' Geomorpha tuberculosa'' Bergroth, 1893 References External links * Hemiptera genera Pentatomidae {{Pentatomidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Florentiamyidae
Florentiamyidae is a family of extinct rodents from North America. They are part of the Superfamily Geomyoidea according to R. L. Carroll 1988. They are known to have existed 33.3 to 15.97 mya. They are known from the Miocene of United States, Harrisonian of United States, Arikareean of United States, and Oligocene of Canada. Four fossil specimens from the Arikareean were obtained at the John Day Fossil Beds in Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t .... References Geomyoid rodents Eocene rodents Eocene Perissodactyla Eocene mammals of North America Paleogene geology of Oregon Prehistoric rodent families John Day Fossil Beds National Monument Extinct rodents Extinct mammals of North America Eocene first appearances Eocene extinctions Rupelian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myomorphous
The zygomasseteric system (or zygomasseteric structure) refers to the anatomical arrangement of the masseter muscle and the zygomatic arch (cheek bone) in the skulls of rodents. This system plays a crucial role in the diverse chewing mechanics observed across rodent species. The zygomatic arch is modified to accommodate the masseter muscle, a primary muscle responsible for jaw movement. The masseter muscle itself is often divided into superficial, lateral, and medial components, allowing for a wide range of jaw motion, particularly the anteroposterior or propalinal movement (front-to-back chewing motion) characteristic of rodents. Variations in the structure of the zygomatic arch and the masseter muscle's insertion points have led to the classification of rodents into four main zygomasseteric types: protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous, reflecting adaptations to different dietary niches and chewing strategies. Protrogomorphy The members of thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masseter Muscle
In anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest. Structure The masseter is a thick, somewhat quadrilateral muscle, consisting of three heads, superficial, deep and coronoid. The fibers of superficial and deep heads are continuous at their insertion. Superficial head The superficial head, the larger, arises by a thick, tendinous aponeurosis from the zygomatic process of the maxilla, the temporal process of the zygomatic bone and from the anterior two-thirds of the inferior border of the zygomatic arch. Its fibers pass inferior and posterior, to be inserted into the angle of the mandible and inferior half of the lateral surface of the ramus of the mandible. Deep head The deep head is much smaller, and more muscular in texture. It arises from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squirrel
Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squirrels are indigenous to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. The earliest known fossilized squirrels date from the Eocene epoch, and among other living rodent families, the squirrels are most closely related to the mountain beaver and dormice. Etymology The word ''squirrel'', first attested in 1327, comes from the Anglo-Norman which is from the Old French , the reflex of a Latin language">Latin word , which was taken from the Ancient Greek word (; from ) 'shadow-tailed', referring to the long bushy tail which many of its members have. ''Sciurus'' is also the name of one of its genuses. The native Old English language, Old English word for the squirrel, , only survived into Middle Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Beaver
The mountain beaver (''Aplodontia rufa'')Other names include boomer, mountain boomer, ground bear, giant mole, gehalis, sewellel, suwellel, showhurll, showtl, and showte, as well as a number of other Native American terms. "Mountain beaver" is a misnomer as the animal is not a true beaver (''Castor'') and it is not restricted to mountains. "Boomer" refers to the loud vocalizations that these usually-solitary animals make when in social situations, but this has not been recorded nor verified. Lewis and Clark originally called the animal "sewellel", a misunderstanding of the Chinook word "she-wal-lal", the name for garments made from the skin of the creature. See Borrecco and Anderson, 1980. is a North American rodent. It is the only living member of its genus, ''Aplodontia'', and Family (biology), family, Aplodontiidae. It should not be confused with true North American beaver, North American and Eurasian beavers, to which it is not closely related; the mountain beaver is instead m ... [...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] |
