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Viatkogorgon And Nochnitsa Skulls
''Viatkogorgon'' is a genus of gorgonopsian (a type of therapsid, the group that includes modern mammals) that lived during the Permian period in what is now Russia. The first fossil was found at the Kotelnich locality near the Vyatka River and was made the holotype of the new genus and species ''V. ivachnenkoi'' in 1999. The generic name refers to the river and the related genus ''Gorgonops''—the gorgons of Greek mythology are often referenced in the names of the group. The specific name honors the paleontologist Mikhail F. Ivakhnenko. The holotype skeleton is one of the most complete gorgonopsian specimens known and includes rarely preserved elements such as gastralia (abdominal ribs) and a sclerotic ring (a bony ring inside the eye). A larger, but poorly preserved specimen has also been assigned to the species. The holotype specimen is about long, including the long skull, making ''Viatkogorgon'' a relatively small gorgonopsian. The assigned specimen is larger, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the sixth and last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the Perm Governorate, region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the Sauropsida, sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Mythology
Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories concern the ancient Greek religion's view of the Cosmogony, origin and Cosmology#Metaphysical cosmology, nature of the world; the lives and activities of List of Greek deities, deities, Greek hero cult, heroes, and List of Greek mythological creatures, mythological creatures; and the origins and significance of the ancient Greeks' cult (religious practice), cult and ritual practices. Modern scholars study the myths to shed light on the religious and political institutions of ancient Greece, and to better understand the nature of mythmaking itself. The Greek myths were initially propagated in an oral tradition, oral-poetic tradition most likely by Minoan civilization, Minoan and Mycenaean Greece, Mycenaean singers starting in the 18th century&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postcranial
The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the vertebrae and ribs, and the appendicular skeleton, which includes girdles and limbs. In paleontology, there may be disagreement over whether the skull and skeleton belong to the same or different animals. One example is the case of the dinosaur ''Nemegtosaurus'', which is known only from a skull that was found in the same geological formation as the related ''Opisthocoelicaudia ''Opisthocoelicaudia'' is a genus of sauropod dinosaur of the Late Cretaceous Period discovered in the Gobi Desert of Mongolia. The type species is ''Opisthocoelicaudia skarzynskii''. A well-preserved skeleton lacking only the head and neck wa ...'', which is only known from postcranial material. References Skeletal system {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulcus (morphology)
In biological morphology and anatomy, a sulcus (: sulci) is a furrow or fissure (Latin ''fissura'', : ''fissurae''). It may be a groove, natural division, deep furrow, elongated cleft, or tear in the surface of a limb or an organ, most notably on the surface of the brain, but also in the lungs, certain muscles (including the heart), as well as in Osteology, bones, and elsewhere. Many sulci are the product of a surface fold or junction, such as in the Gingiva, gums, where they fold around the Cementoenamel junction, neck of the tooth. In invertebrate zoology, a sulcus is a fold, groove, or boundary, especially at the edges of sclerites or between Segmentation (biology), segments. In pollen, a grain that is grooved by a sulcus is termed sulcate. Examples in anatomy Liver *Ligamentum teres hepatis fissure *Ligamentum venosum fissure *Portal fissure, found in the under-surface of the liver *Transverse fissure of liver, found in the lower surface of the liver *Umbilical fissure, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital Bar
The postorbital bar (or postorbital bone) is a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket. It is a trait that only occurs in mammalian taxa, such as most strepsirrhine primates and the hyrax, while haplorhine primates have evolved fully enclosed sockets. One theory for this evolutionary difference is the relative importance of vision to both orders. As haplorrhines (tarsiers and simians) tend to be diurnal, and rely heavily on visual input, many strepsirrhines are nocturnal and have a decreased reliance on visual input. Postorbital bars evolved several times independently during mammalian evolution and the evolutionary histories of several other clades. Some species, such as tarsiers, have a postorbital septum. This septum can be considered as joined processes with a small articulation between the frontal bone, the zygomatic bone and the alisphenoid bone and is therefore different from the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheek Teeth
Cheek teeth or postcanines comprise the molar and premolar teeth in mammals. Cheek teeth are multicuspidate (having many folds or tubercles). Mammals have multicuspidate molars (three in placentals, four in marsupials, in each jaw quadrant) and premolars situated between canines and molars whose shape and number varies considerably among particular groups. For example, many modern Carnivora possess carnassials, or secodont teeth. This scissor-like pairing of the last upper premolar and first lower molar is adapted for shearing meat. In contrast, the cheek teeth of deer and cattle are selenodont. Viewed from the side, these teeth have a series of triangular cusps or ridges, enabling the ruminants' sideways jaw motions to break down tough vegetable matter. Cheek teeth are sometimes separated from the incisors by a gap called a diastema. Cheek teeth in reptiles are much simpler as compared to mammals. Roles and significance Apart from helping grind the food to properly reduce th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos, anteaters and other animals in the order Edentata have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisors are: * maxillary central incisor (upper jaw, closest to the center of the lips) * maxillary lateral incisor (upper jaw, beside the maxillary central incisor) * mandibular central incisor (lower jaw, closest to the center of the lips) * mandibular lateral incisor (lower jaw, beside the mandibular central incisor) Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development. Typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saber-toothed Cat
Machairodontinae (from Ancient Greek μάχαιρα '' machaira,'' a type of Ancient Greek sword and ὀδόντος ''odontos'' meaning tooth) is an extinct subfamily of carnivoran mammals of the cat family Felidae, representing the earliest diverging major branch of the family. Machairodonts varied in size from comparable to lynxes to exceeding that of lions. The Machairodontinae contain many of the extinct predators commonly known as "saber-toothed cats", including those with greatly elongated upper maxillary canines, such as the famed genus ''Smilodon'' and '' Megantereon,'' though the degree of elongation was variable, and in some machairodontines like '' Dinofelis'' the length of the upper canines was much more modest. Sometimes, other carnivorous mammals with elongated teeth are also called saber-toothed cats, although they do not belong to the felids. Besides the machairodonts, other saber-toothed predators also arose in the nimravids, barbourofelids, machaeroidine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canine Tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, eye teeth, vampire teeth, or fangs, are the relatively long, pointed teeth. In the context of the upper jaw, they are also known as '' fangs''. They can appear more flattened, however, causing them to resemble incisors and leading them to be called ''incisiform''. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Individuals of most species that develop them normally have four, two in the upper jaw and two in the lower, separated within each jaw by incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. The four canines in humans are the two upper maxillary canines and the two lower mandibular canines. They are specially prominent in dogs (Canidae), hence the name. Details There are generally four canine teeth: two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serrated
Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pressure at each point of contact is greater, and the points of contact are at a sharper angle to the material being cut. This causes a cutting action that involves many small splits in the surface of the material being cut, which cumulatively serve to cut the material along the line of the blade. Serration in nature In nature, serration is commonly seen in the cutting edge on the teeth of some species, usually sharks. However, it also appears on non-cutting surfaces, for example, in botany where a toothed leaf margin or other plant part, such as the edge of a carnation petal, is described as being serrated. A serrated leaf edge may reduce the force of wind and other natural elements. Probably the largest serrations on Earth occur on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snout
A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, Rostrum (anatomy), rostrum, beak or proboscis. The wet furless surface around the nostrils of the nose of many mammals is called the rhinarium (colloquially this is the "cold wet snout" of some mammals). The rhinarium is often associated with a stronger sense of olfaction. Variation Snouts are found on many mammals in a variety of shapes. Some animals, including ursines and great cats, have box-like snouts, while others, like shrews, have pointed snouts. Pig snouts are flat and cylindrical. Primates Strepsirrhine primates have muzzles, as do baboons. Great apes have reduced muzzles, with the exception being human beings, whose face does not have protruding jaws nor a snout but merely a human nose. Dogs The muzzle begins at the Stop (dog), stop, just below the eyes, and includes the dog's nose and mouth. In the domestic dog, most of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclerotic Ring
The scleral ring or sclerotic ring is a hardened ring of plates, often derived from bone, that is found in the eyes of many animals in several groups of vertebrates. Some species of mammals, amphibians, and crocodilians lack scleral rings. The ring is in the fibrous outer layer of the eye, called the sclera. The structure is commonly referred to as the sclerotic ring; but, because the word ''sclerotic'' often implies pathology of the sclera (''see'' " sclerosis", an unrelated medical condition), recent authors have urged avoiding the use of this term, to avoid confusion and to increase the utility of character comparisons. Scleral rings can be made of cartilaginous material (scleral cartilage) or bony material (scleral ossicles), or often a combination of both, that comes together to form a ring. The arrangement, size, shape, and number of ossicles vary by group. They are believed to have a role in supporting the eye, especially in animals whose eyes are not spherical, or which liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
