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Sciurida
Sciuromorpha ( 'squirrel-like') is a rodent suborder that includes several rodent families. It includes all members of the Sciuridae (the squirrel family) as well as the mountain beaver species. Traditionally, the term has been defined on the basis of the shape of the infraorbital canal. A sciuromorphous zygomasseteric system is characterized by attachment of the lateral masseter muscle along the side of the rostrum. Unlike hystricomorphous and myomorphous rodents, the medial masseter muscle does not pass through the infraorbital canal. Among extant rodents, only the families Sciuridae, Castoridae, Heteromyidae, and Geomyidae are truly sciuromorphous. Some authorities would exclude the Geomyidae and Heteromyidae from that list due to the attachment of the medial masseter directly behind the zygomatic arch. Carleton and Musser (2005) redefined the rodent suborders on morphological and molecular grounds. They defined the Sciuromorpha as including three families, Sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciuridae
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] |
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] |
Zygomasseteric System
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 Rodent, 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hystricomorphous
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] |
Zygomasseteric System
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 Rodent, 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 t ... [...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] |
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] |
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] |
Ammospermophilus Leucurus
The white-tailed antelope squirrel (''Ammospermophilus leucurus'') is a diurnal species of ground squirrel, scientifically classified in the order Rodentia and family Sciuridae, found in arid regions of the southwestern United States and the Baja California Peninsula of northwestern Mexico. Distribution The white-tailed antelope squirrel's geographical range extends north to south from southwestern Oregon to New Mexico, and east to west from western Colorado to Baja California, Mexico.Hall, E. R. 1946. Mammals of Nevada. University of California Press, Berkeley, 710 pp. Home range and population density This species of squirrel has an average home range of , and utilizes approximately in its daily activities. Throughout much of the squirrel's range, especially in Utah, the population density fluctuates greatly, with periods of high density followed by periods of low density. Average population density also varies by season, with higher density in autumn relative to late spri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplodontiidae
The family Aplodontiidae also known as Aplodontidae, Haplodontiidae or Haploodontini is traditionally classified as the sole extant family of the suborder Protrogomorpha. It may be the sister family of the Sciuridae. There are fossils from the Oligocene until Miocene in Asia, from Oligocene in Europe and from the Oligocene until the present in North America, where there is the only living species: the 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 ... (''Aplodontia rufa''). Systematics It includes the following genera: * '' Aplodontia'' Richardson, 1829 * †'' Altasciurus '' Korth, 2019 * †'' Ameniscomys'' Dehm, 1950 * †'' Ansomys'' Qiu, 1987 * †'' Dakotallomys'' Tedrow and Korth, 1999 * †'' Disallomys'' Korth, 2009 * †'' Ephemeromys'' Wang & Heissig, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogeny
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraorder
Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
