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Entepicondylar Foramen
The entepicondylar foramen is an opening in the distal (far) end of the humerus (upper arm bone) present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan '' Plesiorycteropus''. In most Neotominae and all Tylomyinae among cricetid rodents, it is located above the medial epicondyle of the humerus, but it is absent in all Sigmodontinae and Arvicolinae and this trait has been suggested as a synapomorphy for the former subfamily. See also * Supratrochlear foramen The supratrochlear foramen is a small hole located above the trochlea of the humerus of several mammals, it is found frequently in dogs and sometimes in humans, especially women and in the left humerus. It is covered by a layer of connective tissue ... References Literature cited * * {{Refend Mammal anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons. Etymology The word "humerus" is derived from la, humerus, umerus meaning upper arm, shoulder, and is linguistically related to Gothic ''ams'' shoulder and Greek ''ōmos''. Structure Upper extremity The upper or pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...ia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus (biology), fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less developed young which are then nurtured for a period inside the mother's pouch (marsupial), pouch. Anatomical features Placental mammals are anatomically distinguished from othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiorycteropus
''Plesiorycteropus'', also known as the bibymalagasy or Malagasy aardvark, is a recently extinct eutherian mammalian genus from Madagascar. Upon its description in 1895, it was classified with the aardvark, but more recent molecular evidence instead suggests that it is most closely related to the tenrecs (a group extant on the island). Two species are currently recognized, the larger ''P. madagascariensis'' and the smaller ''P. germainepetterae''. They probably overlapped in distribution, as subfossil remains of both species have been found in the same site. Knowledge of the skeletal anatomy is limited, as only limb, partial pelvis, and skull bones have been recovered to date. ''Plesiorycteropus'' was probably a digging animal that fed on insects such as termites and ants. It also shows adaptations for climbing and sitting. Estimates of its mass range from . When and why it became extinct remains unknown. One bone has been radiocarbon dated to 200 BCE; forest dest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neotominae
The Neotominae are a subfamily of the family Cricetidae. They consist of four tribes, 16 genera, and many species of New World rats and mice, predominantly found in North America. Among them are the well-known deer mice, white-footed mice, packrats, and grasshopper mice. Neotomines are related to the other two subfamilies of mice in the New World, the Sigmodontinae and Tylomyinae. Many authorities place them all in a single subfamily, Sigmodontinae. Taxonomy *SUBFAMILY NEOTOMINAE **Tribe Baiomyini ***Genus ''Baiomys'' - pygmy mice **** Southern pygmy mouse, ''Baiomys musculus'' **** Northern pygmy mouse, ''Baiomys taylori'' ***Genus ''Scotinomys'' - brown mice **** Alston's brown mouse, ''Scotinomys teguina'' **** Chiriqui brown mouse, ''Scotinomys xerampelinus'' **Tribe Neotomini ***Genus ''Neotoma'' - pack rats ****Subgenus ''Neotoma'' *****White-throated woodrat, ''Neotoma albigula'' ***** Tamaulipan woodrat, ''Neotoma angustapalata'' *****† Anthony's woodrat, ''Neotoma a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tylomyinae
The subfamily Tylomyinae consists of several species of New World rats and mice including the vesper and climbing rats. They are not as well known as their relatives in the subfamilies Sigmodontinae and Neotominae. Many authorities place all three of these subfamilies in a single subfamily, Sigmodontinae. List of Species *SUBFAMILY TYLOMYINAE **Tribe Nyctomyini ***Genus ''Otonyctomys'' ****Hatt's vesper rat, ''Otonyctomys hatti'' ***Genus ''Nyctomys'' ****Sumichrast's vesper rat, ''Nyctomys sumichrasti'' **Tribe Tylomyini ***Genus ''Tylomys'' ****Chiapan climbing rat, ''Tylomys bullaris'' ****Fulvous-bellied climbing rat, ''Tylomys fulviventer'' ****Mira climbing rat, ''Tylomys mirae'' ****Peters's climbing rat, ''Tylomys nudicaudus'' ****Panamanian climbing rat, ''Tylomys panamensis'' ****Tumbala climbing rat, ''Tylomys tumbalensis'' ****Watson's climbing rat, ''Tylomys watsoni'' ***Genus ''Ototylomys'' ****Big-eared climbing rat, ''Ototylomys phyllotis'' **** La Pera big-ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has members throughout the Americas, Europe and Asia. Characteristics The cricetids are small mammals, ranging from just in length and in weight in the New World pygmy mouse up to and in the muskrat. The length of their tails varies greatly in relation to their bodies, and they may be either furred or sparsely haired. The fur of most species is brownish in colour, often with a white underbelly, but many other patterns exist, especially in the cricetine and arvicoline subfamilies. Like the Old World mice, cricetids are adapted to a wide range of habitats, from the high Arctic to tropical rainforests and hot deserts. Some are arboreal, with long balancing tails and other adaptations for climbing, while others are semiaquatic, with w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Epicondyle Of The Humerus
The medial epicondyle of the humerus is an epicondyle of the humerus bone of the upper arm in humans. It is larger and more prominent than the lateral epicondyle and is directed slightly more posteriorly in the anatomical position. In birds, where the arm is somewhat rotated compared to other tetrapods, it is called the ventral epicondyle of the humerus. In comparative anatomy, the more neutral term entepicondyle is used. The medial epicondyle gives attachment to the ulnar collateral ligament of elbow joint, to the pronator teres, and to a common tendon of origin (the common flexor tendon) of some of the flexor muscles of the forearm: the flexor carpi radialis, the flexor carpi ulnaris, the flexor digitorum superficialis, and the palmaris longus. The medial epicondyle is located on the distal end of the humerus. Additionally, the medial epicondyle is inferior to the medial supracondylar ridge. It is also proximal to the olecranon fossa. The medial epicondyle protects the uln ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigmodontinae
The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World. The "Thomasomyini" from the Atlantic Forest of Brazil are generally thought to be not especially related to the "real" Thomasomyini from the northern Andes and the Amazon rainforest. The genera ''Wiedomys'' and '' Sigmodon'' are generally placed in their own tribe, and the "phyll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arvicolinae
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae (comprising the hamsters and New World rats and mice). Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea. Some refer to the subfamily as the Microtinae (yielding the adjective "microtine") or rank the taxon as a full family, the Arvicolidae. The Arvicolinae are the most populous group of Rodentia in the Northern Hemisphere. They often are found in fossil occlusions of bones cached by past predators such as owls and other birds of prey. Fossils of this group are often used for biostratigraphic dating of paleontological and archeological sites in North America and Europe. Description The most convenient distinguishing feature of the Arvicolinae is the nature of their molar teeth, which have prismatic cusps in the shape of alternati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supratrochlear Foramen
The supratrochlear foramen is a small hole located above the trochlea of the humerus of several mammals, it is found frequently in dogs and sometimes in humans, especially women and in the left humerus. It is covered by a layer of connective tissue. It is not currently recognized with a Terminologia Anatomica name in human anatomy, but the term is still found in older texts and in discussing anatomical variation. See also * Entepicondylar foramen The entepicondylar foramen is an opening in the distal (far) end of the humerus (upper arm bone) present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan ''Plesiorycteropus''. In most Neotominae and al ... References Mammal anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
