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Heteromyid
Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within the genus ''Heteromys'' are also found in forests and their range extends down as far as northern South America. They feed mostly on seeds and other plant parts, which they carry in their fur-lined cheek pouches to their burrows. Although they are very different in physical appearance, the closest relatives of the heteromyids are pocket gophers in the family Geomyidae. Description There are about fifty-nine members of the family Heteromyidae divided among six genera. They are all small rodents, the largest being the giant kangaroo rat (''Dipodomys ingens'') with a body length of and a tail a little longer than this. In many species the tail is tufted and is mainly used for balance. Other adaptations include partially fused vertebrae in the neck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perognathinae
Perognathinae is a subfamily of rodents consisting of two genera of pocket mice. Most species live in complex burrows within the deserts and grasslands of western North America, They feed mostly on seeds and other plant parts, which they carry in their fur-lined cheek pouches to their burrows. Description There are about twenty-six members of the subfamily Perognathinae divided among two genera. They are all small rodents. Adaptations include partially fused vertebrae in the neck, short fore limbs and much enlarged bullae (bubble-shaped bones in the skull). The dental formula is 1/1, 0/0, 1/1, 3/3 making twenty teeth in total. The molars have two-lobed cusps. The upper incisors are grooved and the enamel on the molars is quickly worn away by chewing leaving the dentine exposed. The check teeth have roots. Fur-lined cheek pouches are a feature across the family Heteromyidae. They have openings near the mouth and extend backwards along the sides of the neck. The fur on the animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pocket Mice
Perognathinae is a subfamily of rodents consisting of two genera of pocket mice. Most species live in complex burrows within the deserts and grasslands of western North America, They feed mostly on seeds and other plant parts, which they carry in their fur-lined cheek pouches to their burrows. Description There are about twenty-six members of the subfamily Perognathinae divided among two genera. They are all small rodents. Adaptations include partially fused vertebrae in the neck, short fore limbs and much enlarged bullae (bubble-shaped bones in the skull). The dental formula is 1/1, 0/0, 1/1, 3/3 making twenty teeth in total. The molars have two-lobed cusps. The upper incisors are grooved and the enamel on the molars is quickly worn away by chewing leaving the dentine exposed. The check teeth have roots. Fur-lined cheek pouches are a feature across the family Heteromyidae. They have openings near the mouth and extend backwards along the sides of the neck. The fur on the animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kangaroo Rat
Kangaroo rats, small mostly nocturnal rodents of genus ''Dipodomys'', are native to arid areas of western North America. The common name derives from their bipedal form. They hop in a manner similar to the much larger kangaroo, but developed this mode of locomotion independently, like several other clades of rodents (e.g. dipodids and hopping mice). Description Kangaroo rats are four or five-toed heteromyid rodents with big hind legs, small front legs, and relatively large heads. Adults typically weigh between Nader, I.A. 1978"Kangaroo rats: Intraspecific Variation in ''Dipodomus spectabilis'' Merriami and ''Dipodomys deserti'' Stephens" ''Illinois biological monographs''; 49: 1-116. Chicago, University of Illinois Press. The tails of kangaroo rats are longer than both their bodies and their heads. Another notable feature of kangaroo rats is their fur-lined cheek pouches, which are used for storing food. The coloration of kangaroo rats varies from cinnamon buff to dark gray, dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kangaroo Mice
A kangaroo mouse is either one of the two species of jumping mouse (genus ''Microdipodops'') native to the deserts of the southwestern United States, predominantly found in the state of Nevada. The name "kangaroo mouse" refers to the species' extraordinary jumping ability, as well as its habit of bipedal locomotion. The two species are: *Dark kangaroo mouse – ''Microdipodops megacephalus'' *Pale kangaroo mouse – ''Microdipodops pallidus'' Both species of kangaroo mouse live in sandy desert ecosystems, and forage for seeds and vegetation amongst the scrub brush of their native habitat. The dark kangaroo mouse is also known to feed occasionally on insects and carrion. The mouse rarely drinks water, instead deriving it metabolically from the foods it eats. The kangaroo mouse collects food and maintains large caches in their burrows, which are excavated to a length of between 3 and 8 feet (1 to 2.5 meters). The burrow, the entrance to which the mouse covers during dayl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteromys
''Heteromys'' is a genus of rodents in the family Heteromyidae, commonly known as spiny pocket mice. It is the only extant genus in the subfamily Heteromyinae which also includes the extinct genera ''Diprionomys'' and ''Metaliomys''. ''Heteromys'' was recently enlarged by inclusion of the members of formerly recognized heteromyine genus ''Liomys'', which was found to be paraphyletic. Distribution Heteromyines are distributed from southern Texas to Ecuador and Venezuela, and include all but one of the castorimorph species of South America. Like all of South America's other non-caviomorph rodents, they arrived in the continent relatively recently as part of the Great American Interchange. They inhabit mainly forests; some are also found in scrubland. Taxonomy The genus ''Heteromys'' comprises the following species of spiny pocket mice: * Panamanian spiny pocket mouse (''H. adspersus'') * Trinidad spiny pocket mouse (''H. anomalus'') * Southern spiny pocket mouse (''H. australis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Kangaroo Rat
The giant kangaroo rat (''Dipodomys ingens'') is an endangered species of heteromyid rodent endemic to California. Description The giant kangaroo rat, is the largest of over 20 species of kangaroo rats, which are small members of the rodent family, measuring about in length, including its long, tufted tail. It is tan or brown in color. Like other kangaroo rats it has a large head and large eyes, and long, strong hind leg with which helps it hop at high speeds. The giant kangaroo rat has been recently added to the endangered species list due to its habitat being severely reduced. Data was collected on its foraging behavior and social structure. Traps baited kangaroo rats with oats in them for four weeks in the summer. The animals were captured, tagged with tracking devices and set free. Results show that significantly fewer males were captured. This could have been due to the time of year at which the experiment was tested. Females were found to be more social. Studies also sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipodomyinae
Dipodomyinae is a subfamily of heteromyid rodents, the kangaroo rats and mice. Dipodomyines, as implied by both their common and scientific names, are bipedal; they also jump exceptionally well. Kangaroo rats and mice are native to desert and semidesert ecosystems of western North America from southern Canada to central Mexico. They are generally herbivorous foragers, and dig and live in burrows. Taxonomy Dipodomyinae is the sister group of a Perognathinae-Heteromyinae clade; the two are estimated to have split about 22-24 million years ( Ma) ago. The most recent common ancestor of extant dipodomyines is thought to have lived 15-16 Ma ago, when the two genera split. The most recent common ancestors of extant members of ''Dipodomys'' and ''Microdipodops'' are thought to have lived 10-11 and 7-8 Ma ago, respectively. *Subfamily Dipodomyinae **Genus ''Dipodomys'' — kangaroo rats *** Agile kangaroo rat, ''Dipodomys agilis'' ***California kangaroo rat, ''Dipodomys californicus'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteromyinae
Heteromyinae is a subfamily of rodents in the family Heteromyidae, commonly known as spiny pocket mice. It contains a single extant genus, ''Heteromys'', as well as the extinct genera ''Diprionomys'' and ''Metaliomys''. ''Heteromys'' was recently enlarged by inclusion of the members of formerly recognized heteromyine genus ''Liomys'', which was found to be paraphyletic. Taxonomy Heteromyinae is the sister group of Perognathinae Perognathinae is a subfamily of rodents consisting of two genera of pocket mice. Most species live in complex burrows within the deserts and grasslands of western North America, They feed mostly on seeds and other plant parts, which they carr ...; the two are estimated to have split about 22-23 million years ( Ma) ago. The most recent common ancestor of extant heteromyines is thought to have lived 12-15 Ma ago; the basal species in the subfamily is '' H. salvini''. References Heteromyidae Taxa named by John Edward Gray Mammal subfamilie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masseter Muscle
In human 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 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 the posterior third of the lower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Bulla
The tympanic part of the temporal bone is a curved plate of bone lying below the squamous part of the temporal bone, in front of the mastoid process, and surrounding the external part of the ear canal. It originates as a separate bone (tympanic bone), which in some mammals stays separate through life. Evolutionarily, a portion of it is derived from the angular bone of the reptilian lower jaw. Surfaces Its postero-superior surface is concave, and forms the anterior wall, the floor, and part of the posterior wall of the bony ear canal. Medially, it presents a narrow furrow, the ''tympanic sulcus'', for the attachment of the tympanic membrane. Its antero-inferior surface is quadrilateral and slightly concave; it constitutes the posterior boundary of the mandibular fossa, and is in contact with the retromandibular part of the parotid gland. Borders Its lateral border is free and rough, and gives attachment to the cartilaginous part of the ear canal. Internally, the tympani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostrum (anatomy)
Rostrum (from Latin ', meaning ''beak'') is a term used in anatomy for a number of phylogenetically unrelated structures in different groups of animals. Invertebrates * In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. * Among insects, the rostrum is the name for the piercing mouthparts of the order Hemiptera as well as those of the snow scorpionflies, among many others. The long snout of weevils is also called a rostrum. * Gastropod molluscs have a rostrum or proboscis. * Cephalopod molluscs have hard beak-like mouthparts referred to as the rostrum. File:Washington DC Zoo - Macrobrachium rosenbergii 6.jpg, Crustacean: the rostrum of the shrimp ''Macrobrachium rosenbergii'' is serrated along both edges. File:Gminatus australis with Beetle.jpg, Insect: assassin bug piercing its prey with its rostrum File:Architeuthis beak.jpg, Cephalopod: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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