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Aegisuchus
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull has a rect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegisuchus Brain
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull has a r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegisuchus
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull has a rect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegyptosuchidae
Aegyptosuchidae is an extinct family of eusuchian crocodyliforms from the Cretaceous period of Africa. They are characterized by their large size and flat heads. The family includes two genera, '' Aegyptosuchus'' and '' Aegisuchus''. Aegyptosuchidae was originally established as the monotypic family name for '' Aegyptosuchus peyeri'' in 1933. Upon the discovery of the fellow aegyptosuchid '' Aegisuchus witmeri'' in 2012 by Holliday and Gardner, Aegyptosuchidae was phylogenetically defined as the least inclusive clade containing ''Aegisuchus witmeri'' and ''Aegyptosuchus peyeri'', so long as it does not include ''Alligator mississippiensis'' (American alligator), ''Bernissartia fagesii'', ''Crocodylus niloticus'' (Nile crocodile), ''Gavialis gangeticus'' (gharial), ''Hylaeochampsa vectiana'', or '' Susisuchus anatoceps''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant (living) crocodili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegyptosuchus
''Aegyptosuchus'' ("Egyptian crocodile") is an extinct monospecific genus of aegyptosuchid eusuchian crocodyliform. It was found in the Bahariya Formation of Egypt, which dates back to the Cenomanian age of the Late Cretaceous. The type and only species is ''Aegyptosuchus peyeri''. ''Aegyptosuchus'' is a member of the family Aegyptosuchidae, along with the genus ''Aegisuchus''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant (living) crocodilians. The phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ... can be shown in the cladogram below: References Neosuchians Late Cretaceous crocodylomorphs of Africa Bahariya Formation Fossil taxa described in 1933 Prehist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kem Kem Formation
The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations, the lower Gara Sbaa Formation and the upper Douira Formation. It is exposed on an escarpment along the Algeria–Morocco border. The unit unconformably overlies Paleozoic marine units of Cambrian, Silurian and Devonian age, and is itself capped by limestone platform rock of Cenomanian-Turonian age. It primarily consists of deltaic deposits. The lower Gara Sbaa Formation primarily consists of fine and medium grained sandstone, while the Douira Formation consists of fining-upwards, coarse-to-fine grained sandstones intercalated with siltstones, variegated mudstones, and occasional thin gypsiferous evaporites. Dinosaur remains are among the fossils that have been recovered from the group.Weishampel, David B; ''et al.'' (2004). "Dinosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gharial
The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males have a distinct boss at the end of the snout, which resembles an earthenware pot known as a ''ghara'', hence the name "gharial". The gharial is well adapted to catching fish because of its long, narrow snout and 110 sharp, interlocking teeth. The gharial probably evolved in the northern Indian subcontinent. Fossil gharial remains were excavated in Pliocene deposits in the Sivalik Hills and the Narmada River valley. It currently inhabits rivers in the plains of the northern part of the Indian subcontinent. It is the most thoroughly aquatic crocodilian, and leaves the water only for basking and building nests on moist sandbanks. Adults mate at the end of the cold season. Females congregate in spring to dig nests, in which they lay 20–95 eggs. They guard t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torus
In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not touch the circle, the surface has a ring shape and is called a torus of revolution. If the axis of revolution is tangent to the circle, the surface is a horn torus. If the axis of revolution passes twice through the circle, the surface is a spindle torus. If the axis of revolution passes through the center of the circle, the surface is a degenerate torus, a double-covered sphere. If the revolved curve is not a circle, the surface is called a ''toroid'', as in a square toroid. Real-world objects that approximate a torus of revolution include swim rings, inner tubes and ringette rings. Eyeglass lenses that combine spherical and cylindrical correction are toric lenses. A torus should not be confused with a '' solid torus'', which is formed by r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoccipital
The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cerebrum. At the base of skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord. Like the other cranial bones, it is classed as a flat bone. Due to its many attachments and features, the occipital bone is described in terms of separate parts. From its front to the back is the basilar part, also called the basioccipital, at the sides of the foramen magnum are the lateral parts, also called the exoccipitals, and the back is named as the squamous part. The basilar part is a thick, somewhat quadrilateral piece in front of the foramen magnum and directed towards the pharynx. The squamous part is the curved, expanded plate behind the foramen magnum and is the largest par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epaxial
In adult vertebrates, trunk muscles can be broadly divided into hypaxial muscles, which lie ventral to the horizontal septum of the vertebrae and epaxial muscles, which lie dorsal to the septum. Hypaxial muscles include some vertebral muscles, the diaphragm, the abdominal muscles, and all limb muscles. The serratus posterior inferior and serratus posterior superior are innervated by the ventral primary ramus and are hypaxial muscles. Epaxial muscles include other (dorsal) muscles associated with the vertebrae, ribs, and base of the skull. In humans, the erector spinae, the transversospinales (including the multifidus, semispinalis and rotatores), the splenius and suboccipital muscles are the only epaxial muscles. Hypaxial and epaxial muscles develop directly from somitic cells. Differentiation of hypaxial and epaxial muscles is postulated to have evolved as a new trait in vertebrate animals. Location The hypaxial muscles are located on the ventral side of the body, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrate Bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the lower jaw. The quadrate bone forms the lower jaw articulation in all classes except mammals. Evolutionarily, it is derived from the hindmost part of the primitive cartilaginous upper jaw. Function in reptiles In certain extinct reptiles, the variation and stability of the morphology of the quadrate bone has helped paleontologists in the species-level taxonomy and identification of mosasaur squamates and spinosaurine dinosaurs. In some lizards and dinosaurs, the quadrate is articulated at both ends and movable. In snakes, the quadrate bone has become elongated and very mobile, and contributes greatly to their ability to swallow very ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascularization
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise (especially in older texts). The first vessels in the developing embryo form through vasculogenesis, after which angiogenesis is responsible for most, if not all, blood vessel growth during development and in disease. Angiogenesis is a normal and vital process in growth and development, as well as in wound healing and in the formation of granulation tissue. However, it is also a fundamental step in the transition of tumors from a benign state to a malignant one, leading to the use of angiogenesis inhibitors in the treatment of cancer. The essential role of angiogenesis in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
