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Sciuromorpha
Sciuromorpha ("squirrel-like") is a rodent clade that includes several different 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 familie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reithroparamys
Sciuromorpha ("squirrel-like") is a rodent clade that includes several different 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hystricomorphous
The zygomasseteric system (or zygomasseteric structure) in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal (front-to-back) motion of the rodent jaw is enabled by an extension of the zygomatic arch and the division of the masseter into a superficial, lateral and medial muscle. The four main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous.{* Protrogomorphy The members of this grade include nearly all of the pre-Oligocene rodents of North America and Asia and some of those of Europe. Several lineages survive into the Oligocene or early Miocene, with only one species still alive today, the mountain beaver ('' Aplodontia rufa''). The molerats (family Bathyergidae) are considered secondarily protrogomorphous since their zygomatic condition is clearly derived from a hystricomorphous ancestor. The rostrum of protrogomorph rodents is unmodified an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myomorphous
The zygomasseteric system (or zygomasseteric structure) in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal (front-to-back) motion of the rodent jaw is enabled by an extension of the zygomatic arch and the division of the masseter into a superficial, lateral and medial muscle. The four main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous.{* Protrogomorphy The members of this grade include nearly all of the pre-Oligocene rodents of North America and Asia and some of those of Europe. Several lineages survive into the Oligocene or early Miocene, with only one species still alive today, the mountain beaver (''Aplodontia rufa''). The molerats (family Bathyergidae) are considered secondarily protrogomorphous since their zygomatic condition is clearly derived from a hystricomorphous ancestor. The rostrum of protrogomorph rodents is unmodified and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygomasseteric System
The zygomasseteric system (or zygomasseteric structure) in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal (front-to-back) motion of the rodent jaw is enabled by an extension of the zygomatic arch and the division of the masseter into a superficial, lateral and medial muscle. The four main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous.{* Protrogomorphy The members of this grade include nearly all of the pre-Oligocene rodents of North America and Asia and some of those of Europe. Several lineages survive into the Oligocene or early Miocene, with only one species still alive today, the mountain beaver ('' Aplodontia rufa''). The molerats (family Bathyergidae) are considered secondarily protrogomorphous since their zygomatic condition is clearly derived from a hystricomorphous ancestor. The rostrum of protrogomorph rodents is unmodified an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciuromorphous
The zygomasseteric system (or zygomasseteric structure) in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal (front-to-back) motion of the rodent jaw is enabled by an extension of the zygomatic arch and the division of the masseter into a superficial, lateral and medial muscle. The four main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous.{* Protrogomorphy The members of this grade include nearly all of the pre-Oligocene rodents of North America and Asia and some of those of Europe. Several lineages survive into the Oligocene or early Miocene, with only one species still alive today, the mountain beaver (''Aplodontia rufa''). The molerats (family Bathyergidae) are considered secondarily protrogomorphous since their zygomatic condition is clearly derived from a hystricomorphous ancestor. The rostrum of protrogomorph rodents is unmodified and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Beaver
The mountain beaver (''Aplodontia rufa'')Other names include mountain boomer, ground bear, giant mole, gehalis, lesser sasquatch, sewellel, suwellel, showhurll, showtl, and showte, as well as a number of Chinookan and other Native American terms; "mountain boomer" is a misnomer, and the animal does not make the characteristic tail slapping sound of the true beaver species. See Carraway and Verts, 1993. 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, Aplodontiidae. It should not be confused with true North American and Eurasian beavers, to which it is not closely related, being more closely related to squirrels. There are 7 subspecies of mountain beavers, 6 of which are found in California and 3 of which are endemic to the state. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedetidae
The Pedetidae are a family (biology), family of mammals from the rodent order. The two living species, the springhares, are distributed throughout much of southern Africa and also around Kenya, Tanzania, and Uganda. Fossils have been found as far north as Turkey.McKenna, M.C. and Bell, S.K. 1997. Classification of Mammals: Above the species level. New York: Columbia University Press, 631 pp. (p. 185) Together with the anomalures and Cameroon scaly-tail, zenkerella, Pedetidae forms the suborder Anomaluromorpha. The fossil genus ''Parapedetes'' is also related. Taxonomy The family includes one living genus and three extinct genera. The Asian fossil ''Diatomys'' was previously included, but is now classified in the family Diatomyidae with the Laotian rock rat. *Family Pedetidae **Genus ''Pedetes'' ***South African springhare, ''P. capensis'' ***†''Pedetes gracilis'' ***†''Pedetes hagenstadti'' ***East African springhare, ''P. surdaster'' **Genus †''Megapedetes'' ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mylagaulidae
The Mylagaulidae or mylagaulids are an extinct clade of sciuromorph rodents nested within the family Aplodontiidae. They are known from the Neogene of North America and China. The oldest member is the Late Oligocene '' Trilaccogaulus montanensis'' that lived some 29 million years ago (Mya), and the youngest was '' Ceratogaulus hatcheri''—formerly in the invalid genus "''Epigaulus"'' —which was found barely into the Pliocene, some 5 Mya.Hopkins (2005) Systematics Three subfamilies are recognized. The taxonomy of '' Galbreathia'' is not resolved; it might belong in Mylagaulinae, but lacks the characteristic apomorphies. Promylagaulinae *Genus '' Crucimys'' *Genus '' Promylagaulus'' *Genus '' Trilaccogaulus'' *Genus '' Simpligaulus'' Mesogaulinae *Genus '' Mesogaulus'' - includes ''Mylagaulodon'' Mylagaulinae *Genus '' Alphagaulus'' ( paraphyletic) *Genus '' Ceratogaulus'' - includes "''Epigaulus"'' *Genus '' Hesperogaulus'' *Genus '' Mylagaulus'' *Genus ''Notogaulus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygomatic Arch
In anatomy, the zygomatic arch, or cheek bone, is a part of the skull formed by the zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomatic bone (the side of the cheekbone), the two being united by an oblique suture (the zygomaticotemporal suture); the tendon of the temporal muscle passes medial to (i.e. through the middle of) the arch, to gain insertion into the coronoid process of the mandible (jawbone). The jugal point is the point at the anterior (towards face) end of the upper border of the zygomatic arch where the masseteric and maxillary edges meet at an angle, and where it meets the process of the zygomatic bone. The arch is typical of '' Synapsida'' (“fused arch”), a clade of amniotes that includes mammals and their extinct relatives, such as ''Moschops'' and '' Dimetrodon''. Structure The zygomatic process of the temporal arises by two roots: * an ''anter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Von Brandt
Johann Friedrich von Brandt (25 May 1802 – 15 July 1879) was a German-Russian natural history, naturalist, who worked mostly in Russia. Brandt was born in Jüterbog and educated at a Gymnasium (school), gymnasium in Wittenberg and the Humboldt University of Berlin, University of Berlin. In 1831 he emigrated to Russia, and soon was appointed director of the Zoological Museum of the St Petersburg Academy of Sciences. Brandt encouraged the collection of native animals, many of which were not represented in the museum. Many specimens began to arrive from the expeditions of Nikolai Alekseevich Severtzov, Severtzov, Nikolai Przhevalsky, Przhevalsky, Aleksandr Fyodorovich Middendorf, Middendorff, Leopold von Schrenck, Schrenck and Gustav Radde. He described several birds collected by Russian explorers off the Pacific Coast of North America, including Brandt's cormorant, red-legged kittiwake and spectacled eider. As a paleontologist, Brandt ranks among the best. He was also an entomo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
