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Pleurodont
Pleurodont is a form of tooth implantation common in reptiles of the order Squamata, as well as in at least one temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth .... The vestibular (outer) side of pleurodont teeth are fused ( ankylosed) to the inner surface of the jaw bones which host them. The lingual (tongue) side of pleurodont teeth are not attached to bone, and instead are typically held in place by connective ligaments. This contrasts with thecodont implantation, in which the teeth are set in sockets and surrounded by bone on all sides. References External links Tooth Implantation at palaeos.comOral Cavity of Reptiles - Anatomy and Physiology Dentition types Reptile anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentition Types
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology (that is, the relationship between the shape and form of the tooth in question and its inferred function) of the teeth of an animal. Terminology Animals whose teeth are all of the same type, such as most non-mammalian vertebrates, are said to have ''homodont'' dentition, whereas those whose teeth differ morphologically are said to have ''heterodont'' dentition. The dentition of animals with two successions of teeth (deciduous, permanent) is referred to as ''diphyodont'', while the dentition of animals with only one set of teeth throughout life is ''monophyodont''. The dentition of animals in which the teeth are continuously discarded and replaced throughout life is termed ''polyphyodont''. The dentition of animals in which the teeth are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thecodont Dentition
Thecodont dentition is a morphological arrangement in which the base of the tooth is completely enclosed in a deep socket of bone, as seen in crocodilians, dinosaurs and mammals, and opposed to acrodont and pleurodont dentition seen in squamate reptiles. Notably, this appears to be the ancestral tooth condition in Amniota Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the C .... This morphology was once used as a basis for the now-defunct taxonomic group Thecodontia. References Dentition types Archosaurs {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Shape Changes Within The Jaw (heterodont - Homodont)
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...s, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gingiva, gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The Mammal tooth, teeth of ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamata
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it is also the second-largest order of Neontology, extant (living) vertebrates, after the Perciformes, perciform fish. Squamates are distinguished by their skins, which bear horny scale (zoology), scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the Maxilla, upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very widely to accommodate comparatively large prey. Squamates are the most variably sized living reptiles, ranging from the Sphaerodactylus ariasae, dwarf gecko (''Sphaerodactylus ariasae'') to the reticulated python (''Malayopython reticulatus''). The now-Extinction, extinct mosasaurs reached ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temnospondyl
Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinthodontia, primitive amphibians—that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ResearchGate
ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a 2014 study by ''Nature'' and a 2016 article in ''Times Higher Education'', it is the largest academic social network in terms of active users, although other services have more registered users, and a 2015–2016 survey suggests that almost as many academics have Google Scholar profiles. While reading articles does not require registration, people who wish to become site members need to have an email address at a recognized institution or to be manually confirmed as a published researcher in order to sign up for an account. Articles are free to read by visitors, however additional features (such as job postings or advertisements) are accessible only as a paid subscription. Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankylosis
Ankylosis () is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the Tendon, tendinous or muscular structures outside the joint or of the tissues of the joint itself. When the structures outside the joint are affected, the term "false ankylosis" has been used in contradistinction to "true ankylosis", in which the disease is within the joint. When inflammation has caused the joint-ends of the bones to be fused together, the ankylosis is termed ''osseous'' or complete and is an instance of synostosis. Excision of a completely ankylotic shoulder or elbow may restore free mobility and usefulness to the limb. "Ankylosis" is also used as an anatomical term, bones being said to ankylose (or anchylose) when, from being originally distinct, they coalesce, or become so joined that no motion can take place between them. Causes *A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaw Bones
The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of humans and most animals. Arthropods In arthropods, the jaws are chitinous and oppose laterally, and may consist of ''mandibles'' or ''chelicerae''. These jaws are often composed of numerous mouthparts. Their function is fundamentally for food acquisition, conveyance to the mouth, and/or initial processing (''mastication'' or ''chewing''). Many mouthparts and associate structures (such as pedipalps) are modified legs. Vertebrates In most vertebrates, the jaws are bony or cartilaginous and oppose vertically, comprising an ''upper jaw'' and a ''lower jaw''. The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
