Myliobatidae are free-swimming rays whose pectoral fins make up broad, powerful "wings" which include the eagle and cow-nose rays. They feed on molluscs and have dentitions adapted to crushing. Dentitions of durophagous myliobatids show several specializations in the jaws and teeth related to their diet. The cartilaginous jaws are strengthened by calcified struts (trabeculae), and the palatoquadrate and mandibular symphysis are fused.
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The enlarged posterior teeth of Pyrenasaurus suggest it had a specialized diet, but what it was eating remains unknown because no living lizards have similar dentitions.
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Mioceratodus is an extinct genus of prehistoric sarcopterygian or lobe-finned fish.Consequences of Traumatic injury in Fossil and Recent Dipnoan Dentitions. Kemp, A. Journal of Vertebrate Paleontology. vol, 21.
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It is known from from isolated teeth and vertebral centra as well as at least two associated dentitions. It is an incredibly widespread shark, known from every continent except Australia. This includes a report from Antarctica.
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In physical anthropology, the Australo- Melanesian group is characterized primarily by its characteristic dental morphology.G. Richard Scott, Christy G. Turner II, Grant C. Townsend, María Martinón-Torres, "The Anthropology of Modern Human Teeth: Dental Morphology and Its Variation in Recent and Fossil Homo Sapiens", Cambridge University Press (2018), p. 260. In Java, "Australo-Melanesian dentitions" are found in fossils until the mid-Holocene (c. 5,000 years ago), but are replaced by modern "Southern Mongoloid dentitions" (Sundadonty) in the Neolithic, suggesting the displacement and assimilation of the aboriginal Australo- Melanesian population by the Austronesian expansion.
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Although only a single tooth was found, it showed several derived features that are similar to other early mammalian dentitions, but further detailed comparisons showed the various differences that allowed this tooth to specifically stand out on its own.
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Malan (1963) questioned the rhynchocephalian placement of Palacrodon, viewing it as either a lizard or procolophonid.Malan, M.E. 1963. The dentitions of the South African rhynchocephalia and their bearing on the origin of the rhynchosaurs. South African Journal of Science 59: 14–220.
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The outer margin oblique, with two dentitions below apex. Inner margin lobed at outer angle. Vein 3 from angle of cell, and vein 5 from just above middle of discocellulars. Vein 7 to 9 stalked, from upper angle and veins 10 and 11 free.
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Hungerbühler, A. (2000). Heterodonty in the European phytosaur Nicrosaurus kapffi and its implications for the taxonomic utility and functional morphology of phytosaur dentitions. Journal of Vertebrate Paleontology, 20(1), 31-48. Nicrosaurus in general have massive snouts similar to extanct crocodilians, suggesting they preyed on tetrapods instead of fish.
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Non-carious cervical lesions on an incisor belonging to Australopithecus africanus. Arrows show the location of the lesions. Non-carious cervical lesions (NCCLs) are defined as dental tissue lost at or near the cementoenamel junction (CEJ), and not relating to tooth decay. NCCLs are common in the dentitions of recent human populations.
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Simosuchus has a broadened skull and jaw that resembles a pug, while Anatosuchus has a broad, flat snout like that of a duck. The teeth vary greatly between different genera. Many have heterodont dentitions that vary in shape across the jaw. Often, there are large canine-like teeth protruding from the front of the mouth and broader molar-like teeth in the back.
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In general, E. major has a more robust skull, both in cranial length and breadth, and mandible. Their teeth are specialized and insectivore-like due to their diet. The two species have conspicuously different dentitions, which are more robust in E. major. One of the most noticeable diagnostic differences between these two species is the much more expansive auditory bullae in E. major.
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Cynodesmus once included numerous species of Oligocene and Miocene canid with highly carnivorous (hypercarnivorous) dentitions. A revision of the genus by Wang (1994) indicates that most species previously placed in Cynodesmus are unrelated to the type species, C. thooides. These other species have been placed the genera Carpocyon, Desmocyon, Leptocyon, Metatomarctus, Osbornodon, Otarocyon, Paracynarctus, Paratomarctus, and Phlaocyon (Wang, 1994; Wang et al., 1999).
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They were small animals, averaging about the size of a modern rabbit, had many primitive features. In life, they would have resembled a long-tailed muntjac or chevrotain. Dichobunids had four or five toes on each foot, with each toe ending in a small hoof. They had complete sets of teeth, unlike most later artiodactyls, with their more specialist dentitions.
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They were small animals, averaging about the size of a modern rabbit, had many primitive features. In life, they would have resembled a long-tailed muntjac or chevrotain. Dichobunids had four or five toes on each foot, with each toe ending in a small hoof. They had complete sets of teeth, unlike most later artiodactyls, with their more specialist dentitions.
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The wingspan is about 56 mm. The forewings have a large white patch filling the lower half of the cell and the whole area below except inner margin and extending to near outer margin. Its upper edge has two dentitions, its outer edge is irregular and a large white spot at upper angle of cell. Hindwings with the narrow marginal band.
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In anthropology, Sinodonty and Sundadonty are two patterns of features widely found in the dentitions of different populations in East Asia and Southeast Asia. These two patterns were identified by anthropologist Christy G. Turner II as being within the greater "Mongoloid dental complex".G. Richard Scott, Christy G. Turner, (2000). The Anthropology of Modern Human Teeth: Dental Morphology and Its Variation in Recent Human Populations.
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Bivalves have also been proposed to have evolved from the rostroconchs. Bivalve fossils can be formed when the sediment in which the shells are buried hardens into rock. Often, the impression made by the valves remains as the fossil rather than the valves. During the Early Ordovician, a great increase in the diversity of bivalve species occurred, and the dysodont, heterodont, and taxodont dentitions evolved.
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The Dentitions of the Tritheledontidae (Therapsida: Cynodontia). Proceedings of the Royal Society of London Series B 208(1173):461-481. The genus was named in 1913 on the basis of a partial lower jaw found from South Africa, with the type species being named P. monus. A new species, P. milleri, was named in 1983 and distinguished from the type species in possessing an accessory posterior cusp on the lower postcanines.
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Dr. Max Pleasure introduced the 'Pleasure curve' where he used a reverse Curve of Monson in the premolar area therefore generating a 'lever' balance effect. This concept arose from observations of tooth wear in both human and primate dentitions. The first molars are flat in the horizontal plane and the second molars follow the Curve of Monson. Similarly, the first premolar teeth are shaped such that they have a reverse curve of Monson.
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The acrodont teeth behind them are sharp and triangular, likely adapted for shearing food. Some specimens preserve hatchling teeth between the acrodont and pleurodont teeth, which are conical and laterally compressed. Sphenodontians are also abundant in the Kota microvertebrate assemblage and have acrodont dentitions, raising the possibility that Bharatagama is not one of the earliest lizards but rather a sphenodontian misidentified as a lizard. Bharatagama also shares with sphenodontians an enlarged coronoid process on the lower jaw.
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The family Baurusuchidae was named by Brazilian paleontologist Llewellyn Ivor Price in 1945 to include Baurusuchus. In 1946, American paleontologist Edwin Harris Colbert erected the group Sebecosuchia, which united Baurusuchidae with the family Sebecidae (represented by the genus Sebecus). Both Baurusuchus and Sebecus have deep snouts and ziphodont dentitions (teeth that are serrated and laterally compressed). Other forms were later found that had a close appearance to these two genera, among them Cynodontosuchus, Stratiotosuchus, and Wargosuchus.
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Anodontia is the congenital absence of teeth and can occur in some or all teeth; whereas partial anodontia (or hypodontia), involves two dentitions or only teeth of the permanent dentition (Dorland's 1998). Approximately 1% of the population has oligodontia. Many denominations are attributed to this anomaly: partial anodontia, hypodontia, oligodontia, the congenital absence, anodontia, bilateral aplasia. Anodontia being the term used in controlled vocabulary Medical Subject Headings (MeSH) from MEDLINE which was developed by the United States National Library of Medicine.
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Cretodus simplicatus teeth from Texas, Upper Eagle Ford Group Cretodus is an extinct genus of mackerel sharks belonging to the proposed family Pseudoscapanorhynchidae. It lived during the Late Cretaceous, approximately 100 to 89 million years ago. The genus is best known from formations formed in the Western Interior Seaway, but is also known from the late Cretaceous of Europe, Africa, and possibly Asia. It is mainly known from isolated teeth and vertebral centra, though a few associated dentitions and spines have been found.
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Australopithecus anamensis was found at Asa Issie and Aramis 14, both located in Middle Awash. Fossils found at Asa Issie include “2 partial maxillary dentitions, a partial metatarsal shaft, a foot phalanx, a hand phalanx, 4 vertebral fragments, and a proximal femur” belonging to at least 2 specimens. The cheek teeth of Au. anamensis are much larger than that of Ar. Ramidus, but approximately equal to Au. afarensis. Both individuals have relatively large canines and thicker molar enamel than Ar. Ramidus.
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The scales may be modified into spines for display or protection, and some species have bone osteoderms underneath the scales. Red tegu (Tupinambis rufescens) skull, showing teeth of differing types The dentitions of lizards reflect their wide range of diets, including carnivorous, insectivorous, omnivorous, herbivorous, nectivorous, and molluscivorous. Species typically have uniform teeth suited to their diet, but several species have variable teeth, such as cutting teeth in the front of the jaws and crushing teeth in the rear. Most species are pleurodont, though agamids and chameleons are acrodont.
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The large canines of Tiarajudens were likely used as a defense against predators or as a means of fighting for mates; living mammals such as the water deer and musk deer use their saber teeth for these purposes. The palatal teeth are broad and fit tightly together, an adaptation to consuming fibrous plants. This variation in tooth shape, known as a heterodont dentition, is common in mammals. While most other Permian therapsids had homodont dentitions (teeth of the same shape), Tiarajudens is one of the earliest therapsids to have a heterodont dentition.
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Before the Spanish arrived in the Philippines, decorating teeth was a common practice. From staining them red or black, to decorating them with gold scales, the ornate practice of dental decoration was a status symbol for the Philippine natives. The work of Zumbroich and Salvador-Amores state that only eight out of the fifty-one burials unearthed from the 14th-15th century cemetery site in Bolinao had dentitions with gold ornamentations featuring varying elaborations. Evidence of deliberate teeth dyeing was also pointed out by the discoloration in the frontal teeth only.
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G. pebasensis was named in 2015 on the basis of a nearly complete skull and several lower jaws from the Pebas Formation near Iquitos in Peru. It lived alongside six other species of crocodylians, including two other caimans with crushing dentitions: Kuttanacaiman iquitosensis and Caiman wannlangstoni. The genus name comes from the Quechua word ñatu meaning "small nose" and the species name comes from an Amazonian village called Pebas. A phylogenetic analysis published alongside its initial description placed Gnatusuchus as the most basal member of the clade Caimaninae.
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A meta-analysis of studies conducted between 2001 and 2010 revealed a rate of 5 episodes/1,000 flight-years. Maxillary and mandibular dentitions were affected equally in flight, but in diving, maxillary dentition was affected more than the mandibular dentition, which can indicate a greater role for maxillary sinus pathology in diving barodontalgia. Surprisingly, despite cabin pressurization, the current in-flight barodontalgia incidence is similar to the incidence in the first half of the 20th century. Also, despite the greater fluctuation in divers' pressures, the weighted incidence of barodontalgia among aircrews is similar to the weighted incidence among divers.
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The Cave of Aroeira was first investigated from 1998–2002 revealing a rich lithic assemblage with Acheulean bifaces associated with faunal remains and two human teeth: Aroeira 1 (a left mandibular canine) and Aroeira 2 (a left maxillary third molar). Aroeira 1 is moderately large and Aroeira 2 is among the larger of the Middle Pleistocene upper right third molars. They fit morphologically within the known variation of European Middle Pleistocene dentitions, although Aroeira 2 has a relatively large hypocone. The faunal remains are highly fragmented, mainly consisting of isolated teeth, phalanges, carpal/tarsal bones, and antler fragments.
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The ITRI was established in 1992 by Haeger which utilises both intra-arch and inter-arch relationships to generate index scores to compare the entire dentitions occlusion. This index is of use as it divides the arches into segments which would result in a more accurate outcome. This index evaluates tooth relationships from a morphological perspective which has been of use when evaluating the results of orthodontic treatment, post-treatment stability, settling, relapse and different orthodontic treatment modalities. The ITRI can allow for comparisons to be made in an objective and quantitative manner that allows for statistical analysis of orthodontic outcomes.
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These are rarely as elaborate as those of horseshoe bats (Rhinolophidae), for example, and are sometimes related to sexual selection rather than echolocation; there is no indication that Synemporion had marked sexual differences, and altogether its skull shape is not too different from that of e.g. Australasian big-eared bats (Nyctophilus). One notable difference from all vesper bats it was compared with, however, is the sagittal crest which seems to be completely absent in Synemporion. The teeth are more delicate than in the Hawaiian hoary bat, especially so in the lower jaw; otherwise their dentitions differ little.
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When discovered in the 19th century and during the following decades, Phlaocyon was thought to be ancestral to raccoons because of shared convergent adaptations toward hypocarnivorous dentitions, but was the first to discover the canid nature of the middle ear region in P. leucosteus and Phlaocyon in now believed to be part of very diverse clade of hypocarnivorous canids, the Phlaocyonini, and only distantly related to raccoons. P. mariae and P. yatkolai, both known from isolated teeth and fragmentary material, are the largest and most derived species, and both display a tendency away from the hypocarnivorous dentition of the genus and towards a more hypercarnivorous dentition.
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Because of this, the species was seen as a transitional form between long-snouted, piscivorous metriorhynchids and hypercarnivorous, short- snouted species of Dakosaurus. While Dakosaurus and Geosaurus have ziphodont dentition with teeth that are laterally compressed, Torvoneustes is unique in having a false-ziphodont dentition. The common ancestor of Dakosaurus and Geosaurus may also have had a ziphodont dentition, and as Torvoneustes is also a descendant of this common ancestor, it is possible that a ziphodont dentition was secondarily lost in the genus. However, it is also possible that Dakosaurus and Geosaurus acquired similar dentitions independently, and that Torvoneustes is not descended from a ziphodont ancestor.
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The haplochromine cichlid fishes in the Great Lakes of the East African Rift (particularly in Lake Tanganyika, Lake Malawi, and Lake Victoria) form the most speciose modern example of adaptive radiation. These lakes are believed to be home to about 2,000 different species of cichlid, spanning a wide range of ecological roles and morphological characteristics. Cichlids in these lakes fill nearly all of the roles typically filled by many fish families, including those of predators, scavengers, and herbivores, with varying dentitions and head shapes to match their dietary habits. In each case, the radiation events are only a few million years old, making the high level of speciation particularly remarkable.
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Kuttanacaiman lived in Amazonia at a time before the Amazon River Basin was established; in its place was a massive wetland, called the Pebas Mega-Wetland System, that covered an approximate area of over in a drainage basin east of the still forming Andes, which at the time were experiencing rapid uplift in certain parts. Kuttanacaiman coexisted with six other crocodylian species, including two other caiman species with crushing dentitions: Gnatusuchus pebasensis and Caiman wannlangstoni. Shells belonging to the bivalve genus Pachydon form thick fossil beds in the Pebas Formation and may have been a food source for Kuttanacaiman and these other caimans in swamps and marshes.
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They used their incisors to help dig and unearth buried plants. The way they ate and the shape of their teeth demonstrate that Tritylodons were probably primarily herbivorous (though some tritylodontids show evidence of more omnivorous diets, and modern analogues like rodents tend to be more omnivorous than their dentitions lead on). Any of the Tritylodonts including Tritylodon were warm-blooded or endothermic. Like most non-placental mammalimorphs, it had epipubic bones, aiding in its erect gait but preventing the expansion of the abdomen, making it unable to go through prolonged pregnancy and instead give birth to larval young like modern marsupials and monotremes.
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The matching of the cusps allowed the teeth to occlude more precisely than in earlier cynodonts. It would grind its food between the teeth in somewhat the same way as a modern rodent, though unlike rodents tritylodontids had a palinal jaw stroke (front-to-back), instead of a propalinal one (back-to-front). The teeth were well suited for shredding plant matter; however, there is evidence that some tritylodontids had more omnivorous diets, much in the same vein as modern mammals with "herbivore dentitions" like modern rats. Like mammaliaformes, tritylodontids have epipubic bones, a possible synapomorphy between both clades, and this suggests they may also have laid eggs, or produced undeveloped fetus-like young like modern monotremes and marsupials.
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Joel Irish shows dental traits characteristic of indigenous North Africans and to a lesser extent Southwest Asian and southern European populations. Among the samples included in the study is skeletal material from the Hawara tombs of Fayum, which clustered very closely with the Badarian series of the predynastic period. All the samples, particularly those of the Dynastic period, were significantly divergent from a neolithic West Saharan sample from Lower Nubia. Biological continuity was also found intact from the dynastic to the post-pharaonic periods. According to Irish: > [The Egyptian] samples [996 mummies] exhibit morphologically simple, mass- > reduced dentitions that are similar to those in populations from greater > North Africa (Irish, 1993, 1998a–c, 2000) and, to a lesser extent, western > Asia and Europe (Turner, 1985a; Turner and Markowitz, 1990; Roler, 1992; > Lipschultz, 1996; Irish, 1998a).
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C. wannlangstoni lived through a major climatic and ecological shift in South America during the Middle to Late Miocene. The oldest fossils of the species come from the Pebas Formation, which was deposited during the Middle Miocene about 13 million years ago (Ma) over a vast area of Amazonia called the Pebas mega-wetland. The Pebas mega-wetland developed at the start of the Neogene, coincident with the main phase of uplift of the Andes Mountains and the formation of a massive (>1 million square kilometers) drainage basin that extended from the Andes to the Caribbean Sea. During this time C. wannlangstoni would have inhabited oxygen- poor marshes and swamps, feeding on thick-shelled molluscs alongside other caiman species with crushing dentitions like Gnatusuchus pebasensis and Kuttanacaiman iquitosensis.
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This has been suggested to be a specialisation for hunting large-sized prey items by imparting more powerful bites at the very front of the jaws. This is unlike the condition of most other sebecids, which have more generalised dentitions with similarly sized teeth throughout the jaw, which may have preferred smaller to mid-sized prey. The deeper snout and less compressed, stronger teeth of Bergisuchus also suggest that it was capable of withstanding greater forces relatively than planocraniids, and is inferred to be capable of catching and dismembering prey by thrashing its head in any direction, unlike planocraniids. The unusual differentiated heterodont teeth were interpreted as evidence for a relatively complex method for processing food, and they suggested that Bergisuchus used the large canines at the front of the jaws as fangs and the smaller rear teeth to "chew" and process food before swallowing.
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