They both have a slight diastema, which is very cute.
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And if you weren't familiar with the term DIASTEMA, that section could have caused trouble.
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Mr. Guzzetta has graced us with his themeless presence recently, but today he's back to teach us about DIASTEMA, the technical term for a gap in one's teeth.
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He had all of his teeth, and between his two upper front teeth was a 3-millimeter gap, an inherited condition known as diastema, which Madonna and Elton John also have.
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He took my phone and in the "Notes" app created a glossary list for me, words such as "diastema" (a gap between your teeth à la Lauren Hutton), "afónico" (no voice) and "lampiño" (hairless).
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Diastema cnossia is a species of owlet moth in the family Noctuidae. The MONA or Hodges number for Diastema cnossia is 9068.
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1\. Determining the cause of the diastema, then treat the cause. 2\. Diastema treatment options can differ from one patient to another, but generally it is treated by orthodontics, or composite fillings, or a combination of veneers or crowns.
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Precanine teeth are often replaced by a large diastema in therapsids. Kenomagnathus had both precanine teeth and a diastema, which fills the gap between basal synapsids and therapsids to some extent. It reflects what would have been an ongoing transition, which other stem-mammals with diastemata would also have gone through. Spindler hypothesized that the diastema initially developed as a consequence of the maxilla and premaxilla being angled against each other by the precanine step, which would have prevented the precanine teeth from growing longer; this is seen as an "initial diastema" in "H." garnettensis, Ianthasaurus, and Ianthodon.
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On the mandible the great length of the diastema between the incisors and premolars is a Giraffine characteristic.
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Diastema is a genus of moths of the family Noctuidae. The genus was erected by Achille Guenée in 1852.
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The skull of Riojasuchus Ornithosuchids can be identified by the presence of an arched diastema, a gap between the teeth at the front of the snout. When the jaw is closed, two large curved dentary (lower jaw) teeth fit into the diastema, which is positioned between the premaxilla and maxilla. There are two shallow depressions on the wall of the diastema to accommodate these teeth. The large dentary teeth of Ornithosuchus and Riojasuchus are placed behind a smaller procumbent dentary tooth that sticks out from the jaw.
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Schmitt Gillenwater Kelly syndrome is a rare autosomal dominant congenital disorder consisting of radial hypoplasia, triphalangeal thumbs, hypospadias, and maxillary diastema.
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Mandible of C. stenognathus C. paulistanus has about ten autapomorphies or unique characteristics. The external naris (the nostril opening in the skull) is bordered only by the premaxillae bones. Each premaxilla has four teeth set into it. There is a gap called a diastema in the premaxillary tooth row, and a diastema in between the premaxillary and maxillary teeth.
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Midline diastema (spacing in upper teeth) is a common occurrence in the population. An arbitrary number for the spacing between the teeth to consider as midline diastema is a width of 0.5 from a proximal surface of a teeth to the proximal surface of adjacent teeth. Midline diastema usually occur in the upper teeth compared to lower. The cause of this spacing includes but not limited to microdontia, labial frenulum, peg-shaped lateral incisors, mesiodens, cysts in midlene region, tongue trusting, finger sucking, dental malformations, maxillary incisor proclination, genetics, imperfect joining of interdental septum, dental skeletal discrepancies.
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This would have allowed the corresponding canines on the lower jaw to grow longer and fill the gap, which in turn would have led to a full diastema. However, Spindler also noted that the relationship between the development of the precanine step, tooth loss, and the diastema was unclear, and that the feeding styles of these animals may also have had an effect.
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Seen from above, the diastema formed a wide shelf that sloped downwards on the inner side of the jaw. The small mental foramen was close to the upper middle margin of the diastema. The coronoid process of the mandible appears to have been relatively longer and narrower than in other djadochtatherioideans. It was separated from the alveolar process (where the teeth are contained) by a wide groove.
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Skull of Abdalodon In left lateral view. Photo courtesy of Christian Kammerer. The only existing specimen for Abdalodon is an incomplete, dorsoventrally crushed skull, In which the lower jaws are tightly occluded to the palate. Abdalodon diastematicus is characterized by the presence of diastema between the canines and postcanines of the dentary, and on the maxilla, an even longer diastema between the canines and postcanines.
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Bienotherium is defined as being big and robust compared to other tritylodonts, and also by exposed maxillaries in the skull, an unusually long diastema and thin zygomatic bone.
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They can also result in periodontal disease and diastema. To resolve these you must reduce the enlarged ridges to let the opposing teeth recover and allow the horse to chew correctly.
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When compared to other glossophagines, M. redmani is small to medium-sized. The color of its fur is light brown or gray. The species can also be distinguished from other species in the genus by dental characteristics. The diastema between its upper premolars and the first premolar is at least half the length of the first premolar or longer, while other species have a diastema that is less than half the length of their first premolars.
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The dentary (lower jaw bone) itself is robust and short. The length axis of the p4 makes an angle of about 58° with the length axis of the jawbone. The bone is concave on the lingual, but convex on the labial side. There is a diastema (gap) between the p4 and the incisor that would have been in front of it, as in the jaw of Sudamerica. Gurovich estimated the length of the diastema as 2.5 mm.
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Another diastema of nearly equal length is found between the fifth and sixth alveolus; this diastema is seen in MNHN SAM 124 and is much longer in MSNM V4047 but is absent from Suchomimus and Cristatusaurus. The maxilla fragment referred to Oxalaia (MN 6119-V) has two alveoli and a broken third one that includes a partial tooth. Like the praemaxilla, it had preserved nutrient canals. It also features a shallow dent in the middle, suggesting it was located near the (bony nostrils).
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Sapper is commemorated in the scientific names of two Central American snakes: Amastridium sapperi and Micrurus diastema sapperi.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press.
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M. macpheei has a broad rostrum (front part of the skull) and, like M. brevicaudata, lacks a diastema (gap) between the premolars. A number of details of tooth morphology are characteristic of M. macpheei.
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Although M3 is relatively large, its back part is reduced. The interorbital region is 4.14 mm long and the zygomatic plate is 2.38 mm. The diastema (gap) between the incisors and molars is 6.39 mm long.
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Askeptosaurus also had the following traits differ from the non-askeptosauroid thalattosaurs: 1\. Lack of a fusion between postorbital and postfrontal. 2\. Presence of a homogenous dentition. 3\. Absence of a diastema and palatal dentition. 4\.
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Strumigenys metazytes is a species of ant that has a distinct diastema on the basal portion of the mandibles with 4 sharp teeth and the species has small hairs. The species was described by Bolton in 2000.
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The nasal incision extends fairly far into the upper jaw, ending just posterior to the canine. Forstercooperia possesses a small post-insicor diastema, not as large as its descendants, and similar in size to that of Hyracodon.
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In the skull, it has a significantly longer rostrum (the front part of the skull) and diastema (the gap between the incisors and the molars). Furthermore, it has shorter molar rows in both the upper and lower jaws.
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The lower incisors and canines project forward. The incisors are followed by a long toothless gap, known as the diastema. The general dental formula for bovids is . Most members of the family are herbivorous, but most duikers are omnivorous.
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The mouth consists of a mandible whose height is less than with a mandible ramus depth of less than . The incisive foramen and the diastema are short. The premaxillaries have dorsal extensions. They have large maxillary and mandibular tooth rows.
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The genus Brasilotyphlus has a three-series dentition. The inner mandibular teeth are absent. The maxillary teeth can extend to or past the choanae, but do not always. It has a large diastema, or gap, between its vomerine and palatine teeth.
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Both Abrictosaurus and Heterodontosaurus had very large eyes. Underneath the eyes, the jugal bone projected sideways, a feature also present in ceratopsians. As in the jaws of most ornithischians, the anterior edge of the premaxilla (a bone at the tip of the upper jaw) was toothless and probably supported a keratinous beak (rhamphotheca), although heterodontosaurids did have teeth in the posterior section of the premaxilla. A large gap, called a diastema, separated these premaxillary teeth from those of the maxilla (the main upper jaw bone) in many ornithischians, but this diastema was characteristically arched in heterodontosaurids.
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The height of the lacrimal, which bordered the front of the eye socket, also implies that Kenomagnathus had large eyes. The tooth-bearing bottom margin of the maxilla in Kenomagnathus was more convex than "H." garnettensis, and is unique in that it lacked a concave region (or "precanine step"). Another distinguishing characteristic is the diastema, a toothless region spanning the width of three teeth at the front of the maxilla, where the bone noticeably thinned and could not have borne tooth sockets. Behind the diastema were two precanine teeth, two large canine teeth, and at least fourteen post-canine teeth (eleven being preserved).
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Mandibles mostly smooth with a few weak striae. Masticatory margin of mandible lacking a diastema and possessing four teeth. The third tooth, counting from the apex, is the smallest. A strongly prominent tooth present about midway on the basal margin of mandible.
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Diastema is defined as a space between two adjoining teeth. Food can be trapped between teeth leading to severe periodontal disease and poor dental health overall. It is very difficult to correct. The unopposed overgrowth of the opposing teeth must be reduced.
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The first toe bears a nail rather than a claw, and is opposable. The dental formula is 1/1, 1/1, 1/2, 3/2 with small incisors and a diastema forms between upper and lower incisors.Lekagul, B., J. McNeely. 1977. Mammals of Thailand.
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There is a small diastema between the upper canine and the first premolar (P2), which is smaller and more caniniform than the other premolars. Unlike other lemurs, the first two upper molars (M1 and M2) have prominent lingual cingulae, yet do not have a protostyle.
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Many of the original references deal with specimens or species that were not assigned to E. annectens until later. This is particularly true with the specimens long known, chronologically, as Diclonius mirabilis, Anatosaurus copei, and Anatotitan copei. This toothless section is also known as a diastema.
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344 Salanoia durrelli has a more robust dentition than the brown-tailed mongoose; the teeth have larger surface areas. The first and second upper incisors are smaller than the third, which is separated by a pronounced diastema (gap) from the canine tooth.Durbin et al., 2010, p.
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O'Connor et al., 2006, p. 282 All the teeth are incomplete or absent, and lack both enamel and cementum, but what remains indicates that there was a large incisor at the front and five cheekteeth further back, separated by a diastema (gap) of about 2.5 mm (0.098 in).
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A new species of Machairodus from the late Miocene Kalmakpai locality in eastern Kazakhstan. Ann. Zool. Fennici. Vol. 28, p. 361-369. These canines are not nearly as big as the upper canines. There is a diastema between the canines and the premolars in the lower jaw as well.
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The incisors may have been larger in males. The canine teeth otherwise found behind the incisors were lost. The incisors were separated from the row of cheek teeth by a large diastema (gap). This feature is found in mammals where the incisors and cheek teeth have different specialisations.
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The enamel of the lower premolars is crenulated (has scalloped edges). The fourth premolar is a high triangular shape. Like other ancient cetaceans, and most pronouncely in ambulocetids, the lower molars are shorter than the back premolars. The lower premolars are larger than those of Pakicetus and are separated by wider gaps (diastema).
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It was a large, robust animal reaching 1.5-1.8 m in height and a weight between 1 and 2.5 tons, depending on the species. Both sexes are horn-less. The lower jaw has a widened symphysial part and large tusk-like second incisors separated by a broad diastema. The dental formula is .
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140 The coronoid process (a process in the back part of the bone) is small and the capsular process, which houses the root of the lower incisor, are small. The mental foramen, located in the diastema between the lower incisor and the first molar, opens towards the side, as usual in oryzomyines.
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As in other species of Muroidea, golden mice have an infraorbital foramen with a distinct keyhole shape. Neither canines nor premolars are present. Incisors are sharp and long, separated from the cheek teeth by a diastema. Regional differences occur in the amount of yellowish, reddish and brownish overtones in the dorsal pelage.
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There are four upper and three lower triangular incisors of modest size with canines that are relatively less developed. There are two rows of cheek teeth that are close together and diverge posteriorly. A short diastema separates the cheek teeth and canines. There is no significant contrast between the premolars and molars.
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The frontmost three teeth of the maxilla were also preserved. The premaxillary teeth increased in size from the first to third, shrank from the third to the sixth, and enlarged again from the sixth premaxillary to third maxillary positions. A diastema (gap in tooth row) was present between the last premaxillary and first maxillary tooth.
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The maxillary central incisors contact each other at the midline of the face. The mandibular central incisors are the only other type of teeth to do so. The position of these teeth may determine the existence of an open bite or diastema. As with all teeth, variations of size, shape, and color exist among people.
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The nose protrudes forward, and reaches up to the front of the upper incisor. L. c. pygmaeus is the smallest subspecies, with the narrowest frontal aspects and the longest latus. The Yunnan hare is smaller than the woolly hare; the supraorbitals are flat and small, and the toothrow and diastema (space between two teeth) are of different proportions.
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The skull was roughly 30 mm long and 12 mm tall. The eyes were large and the snout was narrow. Towards the tip of the snout were two small premaxillary teeth, which were separated by a diastema from at least 22 small maxillary teeth. The orbits were directed anteriorly, suggesting that Megalancosaurus had good binocular vision.
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Major changes to the pelvis and feet had already taken place before Australopithecus. It was once thought that humans descended from a knuckle- walking ancestor, but this is not well-supported. Australopithecines have thirty two teeth, like modern humans. Their molars were parallel, like those of great apes, and they had a slight pre-canine gap (diastema).
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Their teeth reflect their diet, and suids retain the upper incisors, which are lost in most other artiodactyls. The canine teeth are enlarged to form prominent tusks, used for rooting in moist earth or undergrowth, and in fighting. They have only a short diastema. The number of teeth varies between species, but the general dental formula is: .
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Diastema tigris, the lantana moth or lantana control moth, is a moth of the family Noctuidae. The species was first described by Achille Guenée in 1852. It is endemic to the US states of Florida and Texas, but has been introduced in Zambia, Australia, Micronesia, Fiji, Hawaii, Ghana, St. Helena, Tanzania, Uganda and Mauritius.Kueffer & Mauremootoo (2004).
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Its teeth were small relative to body size. The lack of a diastema (gap) between the second incisor and first premolar of the mandible indicates that Oreopithecus had canines of size comparable to the rest of its dentition. In many primates, small canines correlate with reduced inter-male competition for access to mates and less sexual dimorphism.
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The generic name Kenomagnathus is derived from the Greek words κένωμα ("gap") and γνάθος ("jaw"), referencing the diastema (gap) in its tooth row. Meanwhile, the specific name scottae honours Diane Scott, a fossil preparator at the University of Toronto Mississauga who "greatly helped with teaching and specimen handling", inspired Spindler's research, and further prepared the specimen in 2013.
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Fossils range in age from the Pliocene and Pleistocene (Blancan to Rancholabrean North American land mammal ages). The known distribution is from southeastern Arizona (Madrean Sky Islands region), to central Texas and from central Colorado to southern Chihuahua. > Aztlanolagus may be distinguished from all other known leporids as follows. > Lower incisor terminates under diastema and well anterior to P3.
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Charles meets Mrs. Ford's attractive mother; she has come from Rome (her daughter had run home to her) and is in the process of settling in to the Ford household. Like Charles, she has a prominent diastema (a space or gap between two teeth). Charles closes the door to her room so they can share an amorous moment alone.
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Spider monkey in Ecuador. Ateles belzebuth has a dental formula of 2.1.3.3. As far as patterns within the teeth, there is a lot of variation but the following are often found within Ateles. Larger incisors and small molars reflect the largely frugivorous diet, with a diastema separating the upper canines from the upper incisors, for the lower incisor.
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Comahuesuchidae is a family of notosuchian crocodyliforms. Constructed in 1991, it includes the genera Comahuesuchus and Anatosuchus. Among the characteristics that are unique to this family is an external naris that is inset into the tip of the snout. There is also a diastema, or gap between the teeth, at the tip of the upper and lower jaws.
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A diastema (plural diastemata) is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars. Diastemata are common for children and can exist in adult teeth as well. Diastemata are primarily caused by imbalance in the relationship between the jaw and the size of the teeth.
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The dentition of Abdalodon helps distinguish it from Procynosuchus, the genus to which it was originally attributed. Charassognathus however bears a similar dental formula to Abdalodon, which has been the basis behind grouping them into the clade Charassognathidae. Charrasognathus however lacks the substantial maxillary and dentary diastema found on Abdalodon, as well as the masseteric fossa, which distinguishes the two.
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The most prominent indigenous deity among Cushitic Horners is Waaq, which continues to be manifested into the modern era with religions such as Waaqeffanna and Waaqism.Aseffa, Abdi, Bula Sirika Wayessa, and Temesgen Burka. "“I have to Resemble My Ancestors through Modification of Midline Diastema”: An Ethnoarchaeological Study of Dental Modification among Karrayyu Oromo, Central Ethiopia." Ethnoarchaeology 8.1 (2016): 57-68.
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At the same time, Nuciruptor does not possess several of the distinctive synapomorphies of extant pitheciins. Nuciruptor remains more primitive than living pitheciins in that no diastema separates its lower incisors from the canine. Its lower canines retain the primitive structure in not having a sharply defined protocristid. P2 is not a robust or high-crowned tooth and does not have a metaconid.
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Food is transferred into these pouches through the diastema. The inside of the pouch contains a large number of folds of dermal papillae. When the pouch is full, it extends and becomes part of the structure of the skin. By 11 days of age, the cheek pouches are fully grown and can carry objects up to the size of a sunflower seed.
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The tusks in the lower jaw fit into an indentation within the diastema of the upper jaw. The cheek-teeth in the lower jaw generally matched those in the upper jaw, though the enamel surface of these were on the outwards side. The upper and lower teeth rows were inset, which created a "cheek-recess" also seen in other ornithischians.
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The Miocene Fauna of La Venta, Colombia. Smithsonian Institution Press, Washington, D.C. pp. 303-318. In the leontiinids, there is a gradual trend towards specialization of the teeth, where this is going developing more the incisors and appears a conspicuous diastema. In Huilatherium, the canine teeth are very reduced in size, reducing the number of anterior incisors and developing tusk-like incisors.
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Between each tooth is a small space, similar to its phylogenetically primitive relatives such as Juxia. Its back teeth, which are separated from the front teeth by a small diastema, consist of four premolars and three molars. These are similar in structure to those of Paraceratherium, with small premolars and larger molars. The latter have low crowns (are brachyodont) and had few enamel folds.
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It had four hoofed toes on each front foot and three hoofed toes on each hind foot. Each toe had a pad on its underside, similar to those of a dog. It had a short face with eye sockets in the middle and a short diastema (the space between the front teeth and the cheek teeth). The skull was long, having 44 low-crowned teeth.
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There was a diastema (gap) between the incisors and molars of the mandible. The lower incisors were broad, recurved, and placed in a straight line across. The p3 premolar tooth of the mandible was present in most early specimens, but lost in later specimens; it was only present in 6% of the La Brea sample. There is some dispute over whether Smilodon was sexually dimorphic.
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Front and side view of Saadanius hijazensis. Saadanius had a longer face than living catarrhines, more closely resembling New World monkeys in appearance, although it was larger—possibly the size of a gibbon. Its enlarged, deep-rooted canine teeth, the diastema between its canine teeth and second incisors, and its sagittal crest suggest that the specimen was a male. These features are shared among male Old World monkeys.
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The two species of Voalavo are only subtly different in morphology. With a body mass of , the eastern voalavo is a small rodent. It has a longer tail than the northern voalavo, as well as a longer rostrum (front part of the skull) and diastema (gap between the incisors and molars), but shorter molar rows. The two species also differ in details of the configuration of the palate.
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Krause et al., 2003, pp. 325-326 Krause and colleagues compared the dentary in detail to that of Sudamerica, the only other gondwanathere for which a substantial fragment of the jaw was known. Sudamerica has only four, not five, cheekteeth (all of which are molariform), a higher, narrower incisor with a root that extends further through the dentary, and a shorter diastema; in all these respects, TNM 02067 is more primitive.
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However, it lacked ever-growing incisors and the diastema found in the aye- aye. The increased anterior dentition is peculiar because it has only happened in lemuriforms, and has never been observed in any of the numerous adapiforms. Key to this possible close affinity with the aye-aye is the identity (canine vs. incisor) of the procumbent front teeth of both species, neither of which is definitively known.
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They all have large, gnawing, incisors separated from grinding molar teeth by a gap, or diastema. Although a few exceptions occur, the dental formula for the great majority of cricetids is: Cricetids' populations can increase rapidly in times of plenty, due to a combination of short gestation periods between 15 and 50 days, and large litter sizes relative to many other mammals. The young are typically born blind, hairless, and helpless.
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Tapirs are the only extant group of perissodactyls with a trunk. Odd-toed ungulates have a long upper jaw with an extended diastema between the front and cheek teeth, giving them an elongated head. The various forms of snout between families are due to differences in the form of the premaxilla. The lacrimal bone has projecting cusps in the eye sockets and a wide contact with the nasal bone.
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Diasporus diastema is a species of frog in the family Eleutherodactylidae. Common names include common tink frog or dink frog, supposedly because of the loud metallic "tink" sound that the male frog makes during the night. It is found in Central America, from Honduras through Nicaragua and Costa Rica to Panama. Its natural habitats are tropical humid lowland forests and montane forests, but it can very disturbed habitats.
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Although the upper canines are shorter than other more famous saber toothed cats such Smilodon, they are still abnormally long in comparison to the rest of the teeth in the mandible. There is also a space separating the canines and premolars known as a diastema. The bottom portion of the jaw contains small incisors that are in a straight row with a large, lower canine.Sotnikova, M. V. 1992.
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Stegosaurus and Huayangosaurus possess a straight tooth row in ventral view, although Scelidosaurus and Jiangjunosaurus do not. The maxilla of Paranthodon preserves the tooth row, and shows that there is little to no overhang. This differs from ankylosaurians, where there is a large overhang of the maxilla. As with Stegosaurus and Silvisaurus, there is a diastema (gap in the tooth row) on the maxilla in front of the tooth row.
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Two-toed sloths have a reduced, ever growing dentition, with no incisors or true canines, which overall lacks homology with the dental formula of other mammals. Their first tooth is very canine-like in shape and is referred to as a caniniform. It is separated from the other teeth, or molariforms, by a diastema. The molariforms are used specifically for grinding and are mortar and pestle-like in appearance and function.
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The genus shows a trend for increased size, with later species being considerably larger than some of its first representatives. Ronzotherium did not possess a nasal horn. Instead the nasal bones were retracted, suggesting the presence of a large prehensile upper lip like those seen in modern rhinoceros species. The lower incisors of Ronzotherium were long and tusk- like, with a large diastema in the lower jaw between the incisors and other teeth.
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Though incompletely preserved, it is assumed that the occipital plate sloped back and upwards from the occipital condyles (as in some relatives). The orbito-temporal vascular system inside the skull of Catopsbaatar did not differ much from those of related genera. Catopsbaatar mandible was robust and very elongated. The diastema (gap between the front and cheek teeth) was concave, and extended for 20 percent of the dentary bone (the main bone of the lower jaw).
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It had a sharply limited band of enamel, and grew continually. The p3 premolar was very small, and adhered entirely to the lower diastema under the larger p4. The blade-like p4 was roughly trapezoidal in side view, and had three cusps along the horizontal upper margin and one cusp on the outer back side. The p4 did not have the ridges on the outer and inner side, as are present in other multituberculates.
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The upper molars have three roots while the lower molars have two roots. General patterns of dental morphological evolution throughout human evolution include a reduction in facial prognathism, the presence of a Y5 cusp pattern, the formation of a parabolic palate and the loss of the diastema. Human teeth are made of dentin and are covered by enamel in the areas that are exposed. Enamel, itself, is composed of hydroxyapatite, a calcium phosphate crystal.
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It was the first non-Cenozoic sebecosuchian to be described, being assigned to the suborder in 1896 by Arthur Smith Woodward. It was described on the basis of an incomplete snout and articulated lower jaw. The presence of a large saber-like second maxillary tooth and a diastema between the maxilla and premaxilla that made room for a large mandibular tooth suggests that Cynodontosuchus is a member of the family Baurusuchidae.Steel, R. (1973). Crocodylia.
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The 8 postcanines of Abdalodon are also outside of the range of ontengenic variation for Procynosuchus, which typically has 9 to 11 postcanines. The long diastema between the canine and the postcanines, in both the upper and lower jaw, is unique to Abdalodon. The main cusp of Abdalodon's postcanines is straighter than those of other early cynodonts. Abdalodon's accessory cusps are proportionally larger when compared to the main cusp than in other early cynodonts.
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The expansion process usually results in a large gap between the patient's two top front teeth, often known as diastema. This gap is closed naturally and the teeth may overlap which leads to braces being needed. Some may develop a large space while others do not develop a space at all. It usually takes a week or two for one to adjust to eating and speaking after first receiving the rapid palatal expander.
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This means that equal amount of dental and skeletal expansion is achieved, compared to RME technique where mostly skeletal expansion is achieved initially. Slow expansion has also been advocated to be more physiologic to the tissues of the maxilla and it causes less pain. Some studies have reported that diastema in slow type of expansion also happens less due to the interdental fibers having chance to close the space as the maxilla is being expanded.
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The dentary (the main toothed bone of the mandible) had a rounded front end which is also expanded upwards. The first two teeth of the dentary were very large, overlapping the snout at the level of the maxillary/premaxillary diastema. This contrasts with other ornithosuchids, which have a smaller tooth in front of the two enlarged teeth. The two enlarged dentary teeth of Venaticosuchus were unserrated and oval-shaped in cross section.
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Their back margin is angular, not rounded as in eastern voalavo. The diastema (the gap between the upper incisors and molars) is shorter than in eastern voalavo. The bony palate is broad and lacks notable ridges and other features, except for a pair of foramina (openings) near the place where the first and second molars (M1 and M2) meet. The back border of the palate is at the level of the middle of the third molars (M3).
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Mammalodon, with a length of , was smaller and more primitive than modern baleen whales. Unlike other baleen whales, Mammalodon had a blunt and rounded snout. The left maxilla–upper jaw–of specimen NMV P199986 preserved four premolars and three molars, and the space between the teeth (diastema) increased towards back into the mouth. The molars decreased in size back into the mouth, like in archeocetes, and the bottom jaw had two more molars than the upper jaw.
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The fossil preserves a bladelike premolar, identified as the fourth premolar, and the piece of the jawbone below it. A diastema (gap) is present between the premolar and the incisor that would have been located in front of it. The alveolus (socket) of the lower incisor extends all the way through the fossil. The p4 bears eight ridges on both sides of the longitudinal crest and is supported by two roots at the front and back.
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The teeth of M. americanum exhibit extreme hypsodonty, indicative of its gritty, fibrous diet. Their teeth in side view show interlocking V-shaped biting surfaces, though they are nearly square in cross-section and exhibit bilophodonty. The teeth are spaced equidistantly in a series, located in the back of the mouth, which leaves space at the predentary; there is no diastema, though the length of this tooth row and of the predentary spout can vary by species.
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Sakis and uakaris have a diastema between the canine and premolar teeth, but the titis, which have unusually small canines for New World monkeys, do not. All species have the dental formula: Females give birth to a single young after a gestation period of between four and six months, depending on species. The uakaris and bearded sakis are polygamous, living in groups of 8-30 individuals. Each group has multiple males, which establish a dominance hierarchy amongst themselves.
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The jaw was double jointed, and the neck was flexible, with an atlas and axis and a double occipital condyle. The teeth were different from those of related cynodonts; there were no canine teeth, and unusually large, rodent-like incisors. There is a large gap, or diastema, separating the cheek teeth from the incisors. The lower jaw of these animals moved back and forth when the mouth was shut so that the food could be chopped up.
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Malocclusion is the imperfect positioning of the teeth when the jaw is closed. In dogs and cats with normal occlusion, the upper incisors rest in front of the lower incisors, the lower canines fit in the diastema between the upper canine and third incisor, the upper first premolars fit behind the lower first premolars, and the upper fourth premolars overlap the lower first molars. Any deviations are known as malocclusions, and they are separated by class.
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In humans, the term is most commonly applied to an open space between the upper incisors (front teeth). It happens when there is an unequal relationship between the size of the teeth and the jaw. Diastema is sometimes caused or exacerbated by the action of a labial frenulum (the tissue connecting the lip to the gum), causing high mucosal attachment and less attached keratinized tissue. This is more prone to recession or by tongue thrusting, which can push the teeth apart.
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Ratus sanila is known only by the discovery of some 7 subfossil fragments of jaw dated to over 3000 years old. The molars of this particular species are broad and have a very complex structure of the cusp. The diastema is also longer than in other species of the genus Rattus suggesting a separate species which may be a relict of an archaic or ancestral dispersal of Rattus stock to New Guinea and Australia. This species probably still survives in some primary forest.
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The 8 upper postcanines on Abdalodon diastematicus are tricuspid, with a large minimally curved main cusp, and two smaller accessory cusps. The accessory cusps are nearly symmetrical and sit anterior and posterior to the main cusp. The roots of the postcanines are thecodont, meaning that the teeth sit in sockets in the middle of the jaw. Four upper incisors are present on both sides of the skull, with the most posterior incisor being separated from the canine by short diastema.
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However, after a rather large diastema with the beak, there were large batteries of cheek teeth on the sides of the jaws: the gaps between the teeth crowns were filled by the points of a second generation of replacement teeth, the whole forming a continuous surface. Contrary to the situation with some related species, a third generation of erupted teeth was lacking. There were twenty-two tooth positions in both lower and upper jaw, for a total of eighty-eight.
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Another very distinctive feature is the presence of two pairs of large front-facing incisors, in the form of tusks and arranged at a 45° angle. These showed continuous growth and were equipped with an enamel band only on the front. It lacked canines, and it also has peculiar premolars and molars, with two transverse high ridges (bilophodonts), whose general appearance is reminiscent of tapir molars. Between the incisors and the posterior teeth there was a space without teeth, the diastema, reaching long.
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It is also common to see signs of attrition, which is wear over time from other tooth contact. The lingual of maxillary incisors and the facial of mandibular incisors are the most common places for attrition to occur. When space exists between the contacts of the maxillary central incisors, the condition is referred to as a diastema or "gap tooth." One frequent cause of the space is the presence of a large labial frenum from the upper lip extending near the teeth.
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A 7.7 millimeter precanine diastema is located behind the upper incisor on that same right side. This seems large, but when compared to incisors of dinocephalians and anomodonts, they are relatively small. Serration is present in NMQR 1702 but it is faint compared to the intense serration of BP/1/816. It is speculated that these differences in serration between NMQR 1702 and BP/1/816 might be ontogenetic, for it is common for juvenile therapsids to lose serration as they get older.
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Because they do not stop growing, the animal must continue to wear them down so that they do not reach and pierce the skull. As the incisors grind against each other, the softer dentine on the rear of the teeth wears away, leaving the sharp enamel edge shaped like the blade of a chisel. Most species have up to 22 teeth with no canines or anterior premolars. A gap, or diastema, occurs between the incisors and the cheek teeth in most species.
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This pseudodont dentition possibly suggests a possibility of a beak being present, similar to turtles and birds. Thalattosauroidea (which contains Clarazia and Thalattosaurus) have a relatively short rostrum, distinct from the elongate primitive condition, with convergent lateral margins that terminate in a pointed tip. It is also characteristic of their supratemporal to contact the frontal bone, having a heavy postorbital bar, diastema present that separates the premaxillary from the maxillary teeth, and a deep lower jaw. The Thalattosauroidea are easily distinguished by their down-turned snouts.
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It had wide gaps (diastema) between the teeth. Its teeth had one of the thickest enamel layers of any known baleen whale, 830–890 μm at the top and 350–380 μm at the base, which is also consistent with a shearing action. It had a crest on the mandible which may have supported proper musculature to pucker its lips. All baleen whales have in their mouth palatal sulci, which carry blood, between tooth sockets, which has generally thought to be indicative of baleen.
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Life restoration Gordodon (meaning "fat tooth") is a genus of edaphosaurid pelycosaur from the Early Permian (the North American Wolfcampian stage, equivalent to the Asselian) of New Mexico. It contains a single species, G. kraineri and was about 1.5 meters (5 feet) long. Gordodon differed from other edaphosaurids in its dentition. Whereas its relatives had their jaws lined with uniformly peg-shaped teeth, Gordodon had enlarged, chisel-like teeth at the front of its mouth, which were separated from the rest by a large diastema.
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Size comparison Terrestrisuchus was a small, slender crocodylomorph with very long legs, quite unlike modern crocodilians. It was initially estimated to have been between long, although this estimate may be based on juvenile specimens and fully grown Terrestrisuchus may have reached or exceeded in length. Its skull was long and narrow, with a tapering, pointed triangular snout lined with sharp curved teeth. The upper jaw margin was straight, and lacked a diastema (a gap in the tooth row) between the maxilla and the premaxilla.
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There are several risk factors leading to the development of black triangles. Papillae dimension can be changed due to any of the following reasons: 1\. Inter-proximal space between teeth; diverging roots can result in the presence of an interproximal space when the contact point between the two clinical crowns is situated too incisally, diverging roots may also be a result of orthodontic treatment. 2\. The increased distance between inter-proximal contact position to bone crest, example to that is the naturally occurring diastema. 3\.
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Some species of jerboa, however, such as Allactaga sibirica, are almost entirely insectivorous. Like other rodents, they have gnawing incisors separated from the grinding cheek teeth by a gap, or diastema. The dental formula for dipodids is: Jerboas and birch mice make their nests in burrows, which, in the case of jerboas, may be complex, with side-chambers for storage of food. In contrast, while jumping mice sometimes co-opt the burrows of other species, they do not dig their own, and generally nest in thick vegetation.
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Kenomagnathus (meaning "gap jaw", in reference to the diastema in its upper tooth row) is a genus of synapsid belonging to the Sphenacodontia, which lived during the Pennsylvanian subperiod of the Carboniferous in what is now Garnett, Kansas, United States. It contains one species, Kenomagnathus scottae, based on a specimen consisting of the maxilla and lacrimal bones of the skull, which was catalogued as ROM 43608 and originally classified as belonging to "Haptodus" garnettensis. Frederik Spindler named it as a new genus in 2020.
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The tritylodont dentition was very different from that of other cynodonts: they did not have canines, and the front pair of incisors were enlarged and were very similar to rodents of today. Tritylodontids had a large gap, called a diastema, that separated the incisors from their square- shaped cheek teeth. The cheek teeth in the upper jaw had three rows of cusps running along its length, with grooves in between. The lower teeth had two rows of cusps which fitted into the grooves in the upper teeth.
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The predentary is joined at the back by the dentary, which constitutes most of the lower jaw. There is a short recess, or diastema, between the articulation of the predentary with the dentary and the first tooth position on the dentary, which is observed in Equijubus, Probactrosaurus, and other hadrosauroids. The front of the dentary characteristically deepens, as in Protohadros, Ouranosaurus, and Bactrosaurus. Two bulges are present on the outer surface of the dentary, one of them representing the coronoid process as in Probactrosaurus and other hadrosauroids.
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In 2019 the production of cube-shaped wombat feces was the subject of the Ig Nobel Prize for Physics, won by Patricia Yang and David Hu. Wombats are herbivores; their diets consist mostly of grasses, sedges, herbs, bark, and roots. Their incisor teeth somewhat resemble those of rodents (rats, mice, etc.), being adapted for gnawing tough vegetation. Like many other herbivorous mammals, they have a large diastema between their incisors and the cheek teeth, which are relatively simple. The dental formula of wombats is .
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The replacing the premolars and the anterior molars are permanently lost, enlarging the post canine diastema in the older specimens. The single replacement of at least some posterior molars and the differentiation of premolars from molars may be a general condition in the stem group of mammals. The skull experienced indeterminate growth while the teeth were being replaced in adult specimens. The dental replacement of Sinoconodon could be interpreted as an intermediate stage in the character evolution from the primitive pattern of polyphyodont replacement seen in most cynodonts to the derived diphyodont replacement of mammals.
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The outer (marginal) tooth row was present solely on the dentary bone, which was narrow and had alternating regions of light and absent texturing. It had at most 33 teeth, including a symphysial fang (an enlarged tooth near the chin) which was only slightly larger than the other dentary teeth. The inner tooth row stretched along four plate-like bones: the parasymphysial plate and three coronoid bones. The parasymphysial plate has a large tooth at its front edge, followed by a smaller tooth and a diastema (toothless area), similar to Ichthyostega.
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The toothcomb is kept clean using a sublingual organ—a thin, flat, fibrous plate that covers a large part of the base of the tongue. The first lower premolar (p2) following the toothcomb is shaped like a canine (caniniform) and occludes the upper canine, essentially filling the role of the incisiform lower canine. There is also a diastema (gap) between the second and third premolars (p2 and p3). The upper incisors are small, with the first incisors (I1) space widely from each other, yet closely to the second incisors (I2).
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Generally, Eritherium shared similarities in the structure of their teeth with other Paenungulata such as the extinct Embrithopoda or early representatives of the manatees, but their teeth are more specialised. The dentition of the mandible that was reconstructed (from two left fragments) made up the complete sequence of the original teeth of mammals: with three incisors, one canine, four premolars and three molars. The tooth row was closed and had no diastema between the canine tooth on the front and back teeth. This primitive mammalian dentition is unique among Proboscideans.
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The subnarial gap resulted in a diastema, a gap in the tooth row (which has also been called a "notch"). Within the subnarial gap was a deep excavation behind the toothrow of the premaxilla, called the subnarial pit, which was walled by a downwards keel of the premaxilla. The outer surface of the premaxilla was covered in foramina (openings) of varying sizes. The upper of the two backwards-extending processes of the premaxilla was long and low, and formed most of the upper border of the elongated naris.
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Indotyphlus are small caecilians, with the largest specimen (a female Indotyphlus battersbyi) measuring in total length. The eyes are visible in sockets, instead of under bone. Other diagnostic characters are absence of temporal fossae, mesethmoid not being exposed dorsally, presence of splenial teeth, secondary grooves, and scales, tentacular opening that is closer to the eye than to the external nostril, no unsegmented terminal shield, smallish narial plugs on tongue, absence of diastema between vomerine and palatine teeth, and absence of terminal keel. Development is probably direct, without aquatic larvae.
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The dental formula of Ocepeia is , meaning it has 3 incisors, 1 canine, 2 premolars, and 3 molars on each side of the upper and lower jaw. The ancestral eutherian condition is four premolars, and the evolutionary loss of the 1st and 2nd premolar, along with lack of a gap (diastema) between the canine and premolar, is one of the unique distinguishing traits of Ocepeia similar to those of simian primates. The large, stout canine teeth of O. daouiensis are 7.7–8 mm (about .3 in) long and also bear subtle similarities to primate canines.
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There is a masseteric scar (associated with the jaw muscles) from below the m1 forward to a point in front of p4, below the mental foramen, an opening in the jawbone. In Apeomys and Megapeomys this scar only reaches to the level of the front root of p4. The mental foramen is very small and opens in the diastema, near the ventral shelf of the scar; in Apeomys and Megapeomys it is located near the dorsal shelf. Further foramina are present on the lingual (inner) surface of the bone, below the cheekteeth.
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It is also distinct in its lack of nasal ornamentation, and in having a reduced diastema. The skull of S. novomexicanum can be distinguished from that of S. validum in features such as the backwards extension of the parietal bone being more reduced and triangular, having larger supratemporal fenestrae (though this may be due to the possible juvenile status of the specimens), and having roughly parallel suture contacts between the squamosal and parietal. It also appears to have had a smaller frontal boss than S. validum, and seems to have been more gracile overall.
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In Hescheleria (and potentially Nectosaurus and Paralonectes), the premaxillae are abruptly downturned at the end of the snout, nearly forming a right angle with the rest of the jaw. In these forms, the end of the snout is a toothy hook separated from the rest of the jaw by a space called a diastema. Thalattosauroids also have heterodont dentition, with pointed piercing teeth at the front of the snout and low crushing teeth further back. The exception to this rule is Gunakadeit, which has a straight snout and many slender teeth.
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The fork-marked lemur dental formula is ; on each side of the mouth, top and bottom, there are two incisors, one canine, three premolars, and three molars—a total of 36 teeth. Their upper first incisor (I1) is long and curved towards the middle of the mouth (unique among lemurs), while the second upper incisor (I2) is small with a gap (diastema) between the two. The upper canines are large, with their tips curved. Their upper anterior premolars (P2) are caniniform (canine-shaped) and more pronounced than in any other living lemur.
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Living in the very southern end of the plains zebra's range, the quagga had a thick winter coat that moulted each year. Its skull was described as having a straight profile and a concave diastema, and as being relatively broad with a narrow occiput. Like other plains zebras, the quagga did not have a dewlap on its neck as the mountain zebra does. The 2004 morphological study found that the skeletal features of the southern Burchell's zebra population and the quagga overlapped, and that they were impossible to distinguish.
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The teeth are closely packed but between the front twenty-four teeth and the rear eight teeth, a distinctive gap is present, a diastema. This is a unique trait but was not formally designated as an autapomorphy because it might be the result of individual variation. Urbacodon resembles Byronosaurus and Mei but differs from most other Troodontidae in that its teeth lack serrations. Urbacodon is distinguished from Byronosaurus by a less vascularized lateral dentary groove and more bulbous anterior tooth crowns, and from Mei by considerably larger size.
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Ruberodon is an extinct genus of traversodontid cynodonts known from the type and only species Ruberodon roychowdhurii from the Late Triassic of India. Ruberodon was named in 2015 on the basis of several isolated lower jaws found in the Tiki Formation. The lower jaw of Ruberodon has three pairs of incisors, one pair of canines, and 9 pairs of postcanine teeth. The first pair of incisors is enlarged and protrudes forward from the tip of the jaw and there is a gap called a diastema between the canines and postcanines.
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In addition, the diastema of ornithosuchids would have weakened the snout, making it more susceptible to damage from large, struggling prey. Their thin teeth were also more structurally weak when dealing with large prey, compared to the conical teeth of modern crocodilians which are sturdy from all directions. Von Baczko proposed that ornithosuchids were specialized scavengers, which could deal with carcasses using their strong bite force and serrated teeth. In this way their slow bite speed and weak snout structure are not as disadvantageous as they would be if ornithosuchids were active predators.
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Brachydiastematherium transylvanicum (literally "short Diastema Beast of Transylvania") is the westernmost species of brontothere, with the first fossils of it being found in Transylvania, Romania. In comparison with other brontothere fossils, it is suggested that B. transylvanicum would have had an elongated head, not unlike Dolichorhinus, and be about 2 meters at the withers (anatomically speaking, the highest part of the back at the base of the neck).Spencer George Lucas und Robert M. Schoch: European Brontotheres. In: Donald R. Prothero und Robert M. Schoch (Hrsg.): The evolution of perissodactyls.
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A diastema occurs between the incisors and the cheek teeth. The dental formula for hyraxes is . A hyrax showing its characteristic chewing and grunting behavior and its incisor tusks Although not ruminants, hyraxes have complex, multichambered stomachs that allow symbiotic bacteria to break down tough plant materials, but their overall ability to digest fibre is lower than that of the ungulates. Their mandibular motions are similar to chewing cud, but the hyrax is physically incapable of regurgitation as in the even-toed ungulates and the merycism of some of the macropods.
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On the labial (outer) surface of the dentary, there is one large mental foramen (opening). The mandibular symphysis, where the two halves of the lower jaw meet, is poorly preserved, but there is nothing to suggest that the left and right dentaries were fused. The lower margin of the bone is convex at the front, but concave further back, so that the depth of the dentary is 8.3 mm (0.33 in) below the diastema, but only 7.0 mm (0.28 in) below the third cheektooth. The origin of the coronoid process, a projection at the back of the dentary, lies far to the front.
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Young named the genus after the Ordos Desert, the region where the jaw was found. Ordosiodon was originally identified as a type of diademodontid by Young (diademodontids are herbivorous cynodonts that are much more closely related to mammals than are therocephalians). Young noted several unusual features of Ordosiodon that set it apart from diademodontids, including the lack of a diastema or gap in the teeth, the lack of molar-like sectorial teeth at the back of the jaw, conical caniniform teeth, and relatively small postcaniniform teeth. Ordosiodon was later identified as a juvenile diademodontid to account for these differences.
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A strain vector biomechanical investigation of the skull, mandible and teeth of a well-preserved last cold stage individual recovered from Whitemoor Haye, Staffordshire, revealed musculature and dental characteristics that support a grazing feeding preference. In particular, the enlargement of the temporalis and neck muscles is consistent with that required to resist the large tugging forces generated when taking large mouthfuls of fodder from the ground. The presence of a large diastema supports this theory. Comparisons with living perissodactyls confirm that the woolly rhinoceros was a hindgut fermentor with a single stomach, consuming cellulose- rich, protein-poor fodder.
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Apeomyoides savagei is a large eomyid, though not as large as Megapeomys lindsayi and M. bobwilsoni. Megapeomys repenningi from Japan is similar in size, but its cheekteeth are not as high- crowned. A. savagei shows a series of traits that are characteristic for the apeomyines: high-crowned cheekteeth with thick enamel that are bilophodont (divided into two lobes) in form and a very long diastema (gap) between the lower incisor and cheekteeth. However, the cheekteeth are higher-crowned than those of other apeomyines, including Apeomys, Megapeomys, and Arikareeomys, and they are rectangular in shape, while other apeomyines have barrel-shaped teeth.
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Syncline IV, which is located at the back of the tooth, between the hypolophid and posterolophid, is closed at the margins; this valley is open in Megapeomys bobwilsoni. Syncline IV also opens into the centrally located syncline III; this opening is absent in Arikareeomys. There are two roots under p4 and three under each of the molars, fewer than in Megapeomys bobwilsoni, which shows three under p4 and four under the molars. On the mandible, the diastema is very large and the incisor is procumbent (projecting forward), which distinguishes Apeomyoides from most eomyids apart from Megapeomys.
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The upper lip is constrained by this connection and has fewer nerves to control movement, which leaves it less mobile than the upper lips of simians. The philtrum creates a gap (diastema) between the roots of the first two upper incisors. The strepsirrhine rhinarium can collect relatively non-volatile, fluid-based chemicals (traditionally categorized as pheromones) and transmit them to the vomeronasal organ (VNO), which is located below and in front of the nasal cavity, above the mouth. The VNO is an encased duct-like structure made of cartilage and is isolated from the air passing through the nasal cavity.
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There were three premaxillary teeth. In the Early Jurassic Abrictosaurus, Heterodontosaurus, and Lycorhinus, the first two premaxillary teeth were small and conical, while the much larger third tooth resembled the canines of carnivoran mammals and is often called the caniniform or 'tusk'. A lower caniniform, larger than the upper, took the first position in the dentary and was accommodated by the arched diastema of the upper jaw when the mouth was closed. These caniniforms were serrated on both the anterior and posterior edges in Heterodontosaurus and Lycorhinus, while those of Abrictosaurus bore serrations only on the anterior edge.
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There is a large diastema, or gap, between the keratinous beak on the front of the mouth and the main chewing teeth in the side of the mouth, which would allow the two sections to work independently, so Altirhinus could crop with its beak while simultaneously chewing with its teeth. Many herbivorous mammals show a similar adaptation and can crop with their incisors without disturbing their chewing molars. Altirhinus was one of a number of advanced iguanodontians with snouts expanded outwards towards the end. This is quite possibly an example of convergent evolution with hadrosaurids, famous for their wide "duckbill" snouts.
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H. serum skull The name Homotherium (Greek: (, 'same') and (, 'beast')) was proposed by Emilio Fabrini (1890), without further explanation, for a new subgenus of Machairodus, whose main distinguishing feature was the presence of a large diastema between the two inferior premolars. The lineage of Homotherium is estimated (based on mitochondrial DNA sequences) to have diverged from that of Smilodon about 18 million years ago. Homotherium probably derived from Machairodus and appeared for the first time at the Miocene–Pliocene border, about 4 to 5 million years ago.Alan Turner: "The Evolution of the guild of larger terrestrial carnivores during the Plio- Pleistocene in Africa".
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The canines had fine serrations along the back edge, but only the lower ones were serrated at the front. Eleven tall and chisel-like cheek-teeth lined each side of the posterior parts of the upper jaw, which were separated from the canines by a large diastema (gap). The cheek-teeth increased gradually in size, with the middle teeth being largest, and decreased in size after this point. These teeth had a heavy coat of enamel on the inwards side, and were adapted for wear (hypsodonty), and they had long roots, firmly embedded in their sockets.
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Life restoration The total body length of Venaticosuchus is unknown, considering that only skull and jaw material is known in the present day. The jaw had a total length of 26.0 centimeters (10.2 inches), which was marginally larger than the largest known jaws from Ornithosuchus and Riojasuchus (excluding the massive and enigmatic archosaur "Dasygnathoides", which has historically been considered a synonym of Ornithosuchus). Other ornithosuchids were medium-sized reptiles, slightly less than 2 meters (6.6 feet) in length. The side of the snout was formed by the toothed maxilla and premaxilla bones, which were separated by a toothless gap known as a diastema.
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This is similar to the case in other ornithosuchids, and Venaticosuchus particularly resembles Riojasuchus due to the maxilla curving upwards behind the diastema and the premaxilla hooking downwards in front of it. The premaxilla is not preserved well enough to conclude anything about its tooth count, but other ornithosuchids had three premaxillary teeth. The maxilla in general resembles that of Riojasuchus, with a triangular antorbital fenestra with a tapering front tip. On the other hand, the antorbital fossa (the basin in which the antorbital fenestra lies) is shallower, smaller, and more smoothly textured than that of Riojasuchus.
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The outer face of the dentary also has a depression near the tooth row about midway down the length of the bone. This depression would have received the maxillary fang while the mouth was closed, similar to how the diastema at the front of the maxilla would have received the dentary fang. The surangular and angular (a pair of untoothed bones in the rear part of the lower jaw) are deep. The articular bone, which houses the jaw joint at the rear end of the lower jaw, is concave and opens towards the rear, similar to that of phytosaurs.
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In lemuriform primates, the toothcomb may also play a secondary role in olfaction, which may account for the size reduction of the poorly studied upper incisors. The toothcomb may provide pressure to stimulate glandular secretions which are then spread through the fur. Furthermore, the size reduction of the upper incisors may create a gap between the teeth (interincisal diastema) that connects the philtrum (a cleft in the middle of the wet nose, or rhinarium) to the vomeronasal organ in the roof of the mouth. This would allow pheromones to be more easily transferred to the vomeronasal organ.
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The Yunnan bush rat (Hadromys yunnanensis) is a species of rodent from the family Muridae. It has just recently been released from synonymy with the Manipur bush rat, and so there is very little information about it. It was recognized as a separate species due to its much larger body size in comparison to the Manipur bush rat, relatively shorter tail, pure white underparts as opposed to gray, significantly shorter diastema, and shorter palate in relation to its skull. It is located only in Yunnan province of the People's Republic of China, where it known only from Tongbiguan Nature Reserve in Ruili City.
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The undersides of the praemaxillae are greatly ornamented in Oxalaia, in contrast to the smoother condition it has in other spinosaurids. restoration based on relatives The praemaxillae have seven (tooth sockets) on each side, the same number found in Angaturama, Cristatusaurus, Suchomimus, and MNHN SAM 124 (referred to Spinosaurus); MSNM V4047, another upper jaw specimen from Spinosaurus, had only six. It cannot be confirmed whether this lower number of teeth is due to ontogeny; for that, a larger sample size is necessary. A large diastema (gap in tooth row) separates the third tooth socket from the fourth; this is observed in all other spinosaurids, being smaller in Suchomimus.
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The toothcomb is kept clean by the sublingua or "under-tongue", a specialized structure that acts like a toothbrush to remove hair and other debris. The sublingua extends below the tip of the tongue and is tipped with keratinized, serrated points that rake between the front teeth. Slow lorises have relatively large maxillary canine teeth, their inner (mesial) maxillary incisors are larger than the outer (distal) maxillary incisors, and they have a diastema (gap) between the canine and the first premolar. The first mandibular premolar is elongated, and the last molar has three cusps on the crown, the shortest of which is near the back.
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There are large pneumatic openings in the posterior mandible and the whole of the mandible is hollow and was likely air-filled (pneumatic). Caelestiventus is a heterodont, with three different tooth shapes - long fang-like spikes, large "leaf-shaped" blades, and tiny blades. There are two long, spike-shaped teeth near the front of each side of the lower jaws that were likely opposed by similar teeth at the tip of the skull snout (premaxilla). In the lower jaws, behind the fangs, there is a tooth gap (diastema) which is followed by 38 tiny teeth on each side of the lower jaw (mandibular ramus).
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Abnormal swallowing patterns push the upper teeth forward and away from the upper alveolar processes and cause open bites. In children, tongue thrusting is common due to immature oral behavior, narrow dental arch, prolonged upper respiratory tract infections, spaces between the teeth (diastema), muscle weakness, malocclusion, abnormal sucking habits, and open mouth posture due to structural abnormalities of genetic origin. Large tonsils and adenoids also contribute to tongue thrust swallowing. From the dental perspective, teeth move in relation to the balance of the soft tissue; the normal relationship of teeth lies in occlusion; and any deviation from the normal occlusion can lead to dental distress.
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Upper and lower primary teeth should be correctly occluding and aligned after 2 years whilst they are continuing to develop, with full root development complete at 3 years of age. Around a year after development of the teeth is complete, the jaws continue to grow which results in spacing between some of the teeth (diastema). This effect is greatest in the anterior (front) teeth and can be seen from around age 4 – 5 years. This spacing is important as it allows space for the permanent (adult) teeth to erupt into the correct occlusion, and without this spacing there is likely to be crowding of the permanent dentition.
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Life restoration Goyocephale is known from a partial skull, including both mandibles, the skull roof, part of the occiput, part of the braincase region, the posterior skull, the premaxilla, and the maxilla. The posterior edge of the skull roof, at the edge of the squamosal bones, has many small bony bumps, which would have been the base of small horns in life. A feature shared with pachycephalosaurids, Goyocephale had a heterodont dentition, with large caniniform premaxilla teeth, followed by a diastema between the premaxilla and the maxilla, and the regular sub- triangular teeth in the maxilla. Teeth in the premaxilla become larger farther posterior, with the last being the largest.
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This consists of a prominent central cusp, an anterior accessory cusp, and a posterior accessory cusp, resulting in a symmetrical distribution (this trait is more derived than any other Probainognathian). The postcanines seen in Brasilitherium, on the other hand, has morganucondontid-like plan in lower postcanines. Due to the size of the diastema between canines and postcanines in the largest Brasilodontids, this shows that anterior postcanines were most likely lost faster than it was in Thrinaxodon (an early cynodont). Although it is not known how many successional postcanine replacements there are in Brasilodon, there is more than one replacement (polyphyodonty), and it is done the same way as many cynodonts, in which postcanines are replaced in an alternate manner.
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The first three pairs of its maxillary teeth are large caniniform teeth, and in its lower jaw there are also three pairs of large caniniform teeth which are located immediately in front of the three maxillary caniniforms when the mouth is closed. Two pairs of the lower jaw caniniforms occlude between the last pair of premaxillary teeth and first pair of maxillary teeth in a diastema (gap in the tooth row). The enlargement of these two pairs of lower jaw teeth in K. queenslandicus may be related to the absence of a fifth pair of premaxillary teeth, which are present in a number of other pliosaurs. Oliver Hampe described Kronosaurus boyacensis as having five pairs of premaxillary teeth.
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It also has a long, sheet-like process of the maxilla that extends back to the anterolateral part of the maxilla–frontal contact medial to the external naris, and terminates just anterior to midlength of the orbital. Finally, the suture between the premaxilla and parietal bone is located around orbital midlength. P. westburyensis also possesses a unique combination of characters, including: low dentary alveolar count including only 18 postsymphysial alveoli; teeth fully trihedral in cross-section, possessing a flat, anteroposteriorly broad labial surface lacking enamel ridges; relatively slight mediolateral expansion of premaxilla and maxillary caniniform region; six premaxillary alveoli; lack of anisodont premaxillary dentition; lack of diastema between maxillary and premaxillary alveolar rows; and cervical centra lacking ventral ridge.
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The flanges on the bottom of the pterygoids come into contact with each other at the midline of the skull. On the bottom of the cervicals, there are large foramina, or pits. The number of cervical vertebrae in Luskhan (14) can be seen as intermediate between Pliosaurus (18) and Brachauchenius (12). Unusually, Luskhan also lacks many of the adaptations for hunting large prey seen in other brachauchenines: the snout is very thin; there is no keel on the bottom of the fused symphysis of the lower jaw; there is no diastema (or gap in the tooth row); the bones of the upper jaw (the premaxilla and maxilla) are expanded outwards; and there are no caniniform ("canine-like") teeth.
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The teeth were set obliquely along the length of the jaws, and overlapped each other slightly from front to back. On each side, the most complete specimen (UALVP 2) had three teeth in the premaxilla, sixteen in the maxilla (both part of the upper jaw), and seventeen in the dentary of the lower jaw. The teeth in the premaxilla were separated from those behind in the maxilla by a short diastema (space), and the two rows in the premaxilla were separated by a toothless gap at the front. The teeth in the front part of the upper jaw (premaxilla) and front lower jaw were similar; these had taller, more pointed and recurved crowns, and a "heel" at the back.
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The potoroids are smaller relatives of the kangaroos and wallabies, and may be ancestral to that group. In particular, the teeth show a simpler pattern than in the kangaroo family, with longer upper incisors, larger canines, and four cusps on the molars. However, both groups possess a wide diastema between the incisors and the cheek teeth, and the potoroids have a similar dental formula to their larger relatives: In most respects, however, the potoroids are similar to small wallabies. Their hind feet are elongated, and they move by hopping, although the adaptations are not as extreme as they are in true wallabies, and, like rabbits, they often use their fore limbs to move about at slower speeds.
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Teeth of a koala, from left to right: molars, premolars (dark), diastema, canines, incisors The koala has several adaptations for its eucalypt diet, which is of low nutritive value, of high toxicity, and high in dietary fibre. The animal's dentition consists of the incisors and cheek teeth (a single premolar and four molars on each jaw), which are separated by a large gap (a characteristic feature of herbivorous mammals). The incisors are used for grasping leaves, which are then passed to the premolars to be snipped at the petiole before being passed to the highly cusped molars, where they are shredded into small pieces. Koalas may also store food in their cheek pouches before it is ready to be chewed.
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They breed during the rainy season (December to March) and lay 5 to 6 eggs underneath logs or in ant hills. Thee average adult size of Cyclocorus is about 40 cm, and the maximum size is about 48 cm in total length. Cyclocorus are gray-brown with indistinct dark lines along the back, yellowish or white on the belly with many black blotches, and a series of tiny white dots along the sides of the belly. Snakes in this genus have small eyes with round pupils, smooth dorsal scales in 17 rows, and unusual dentition, wherein the anterior three to seven maxillary teeth increase in size, terminating in two very large fang-like teeth, followed by a short diastema and 12 to 15 smaller teeth.
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This means that the dental formula for sheep is either or There is a large diastema between the incisors and the molars. In the first few years of life one can calculate the age of sheep from their front teeth, as a pair of milk teeth is replaced by larger adult teeth each year, the full set of eight adult front teeth being complete at about four years of age. The front teeth are then gradually lost as sheep age, making it harder for them to feed and hindering the health and productivity of the animal. For this reason, domestic sheep on normal pasture begin to slowly decline from four years on, and the life expectancy of a sheep is 10 to 12 years, though some sheep may live as long as 20 years.
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Closeup showing the diastema of Kenomagnathus Modern mammals (except whales) commonly exhibit heterodont teeth, or teeth of several different types. Among the extinct relatives (stem group) of mammals, there is a gradient from animals with isodont (uniform) teeth to animals with heterodont teeth, associated with the development of distinct "zones" along the tooth row. Canine-like teeth — double canines like that of Kenomagnathus in particular — are common among basal synapsids and also other basal amniotes, along with the enlargement of the first premaxillary tooth at the front of the skull. There is a morphological gap between basal synapsids like "Haptodus" garnettensis, which have precanine teeth but less tooth variation over all, and therapsids (which are closer to mammals), which have no precanine teeth, only one set of canines, and more subtle tooth variation.
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Considering the NOM-059-SEMARNAT-2010, 25 species are cataloged in risk included in 17 subject to special protection (for example K. scorpioides, Pseudelaphe phaescens, Imantodes gemmistratus, Crotalus tzabcan = C. durissus, among others), 7 threatened ( for example Coleonyx elegans, Ctenosaura similis, Boa imperator = B. constrictor imperator, among others) and 1 endangered (Ctenosaura defender). Ctenosaura similis and C. defender are considered species and priority populations for conservation (Official Gazette of the Federation, 2014). A species with distribution in the Reserve (Micrurus diastema) is endemic to Mexico and 23 species (37%) are endemic to the Yucatan Peninsula (for example T. yucatana, C. defender, Sceloporus chrysostictus, Coniophanes meridanus, among others). Globally, 69% of the reptiles with distribution in the Reserve are classified by the IUCN as of minor concern, R. areolata is considered almost threatened; T. yucatana and C. defender as vulnerable.
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The type specimen, KNM-WT 16999 is composed of a long distinct snout, the facial skeleton, frontal, much of the coronal structure, most of the sphenoid, and relatively unworn adult dentition; the right orbit (virtually complete), the right zygomatic, the pterygoid, most of the sphenoid and lesser wings, the maxilla and premaxilla, and adult dentition with procumbent incisors. The surface on the right side maxilla and premaxilla along with the enamel on the right molars has been lost over time and has been replaced with calcite crystals, which only provide the general shape and not the details. From dentition it is known that the palate, which is almost completely calcified, of A. turkanensis is shallow, long and narrow with tooth rows that converge posteriorly, and it is probable the tooth rows were originally nearly parallel. A. turkanensis had a 6.5mm diastema between its very procumbent second incisor (KNM-WT 16999 had large, broad incisors) and the canine.
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The neusis construction consists of fitting a line element of given length (a) in between two given lines (l and m), in such a way that the line element, or its extension, passes through a given point P. That is, one end of the line element has to lie on l, the other end on m, while the line element is "inclined" towards P. Point P is called the pole of the neusis, line l the directrix, or guiding line, and line m the catch line. Length a is called the diastema (διάστημα; Greek for "distance"). A neusis construction might be performed by means of a 'neusis ruler': a marked ruler that is rotatable around the point P (this may be done by putting a pin into the point P and then pressing the ruler against the pin). In the figure one end of the ruler is marked with a yellow eye with crosshairs: this is the origin of the scale division on the ruler.
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A recent analysis of Gloxinia and related genera based on molecular and morphological work has determined that Wiehler's circumscription of the genus was unnatural, both phylogenetically and morphologically. The analyses demonstrated that the genera Anodiscus and Koellikeria, each with a single species, were more closely related to Gloxinia perennis than were any of the other species included in Gloxinia by Wiehler, several of which proved to be more closely related to other genera (particularly Diastema, Monopyle, and Phinaea). As a result of this work, most of the species have been transferred to other genera while Koellikeria erinoides and Anodiscus xanthophyllus have been transferred into a much more narrowly defined Gloxinia consisting of only three species, all of them characterized by having a raceme-like flowering stem. The other species have been transferred to the existing genus Monopyle, the resurrected genera Mandirola and Seemannia, and the new genera Gloxinella, Gloxiniopsis, Nomopyle, and Sphaerorrhiza.
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Its skull is damaged, but its unusual dentition is preserved. The incisors (two on each side of the upper and one on each side of the lower jaw) project forwards and are separated from the three or four cheektooth in each side of the lower and upper jaws by a large diastema (gap). It shows primitive features, such as the presence of epipubic bones (in the pelvis), a septomaxilla (a small bone placed between the premaxilla and the maxilla in the upper jaw), and a deep zygomatic arch (cheekbone). On the other hand, it has derived traits like the presence of a well-developed trochlea on the distal (far) end of the humerus (upper arm bone), the absence of a rim at the dorsal (upper) margin of the acetabulum (the opening in the pelvis which receives the head of the femur), a small lesser trochanter of the femur (upper leg bone), reduced contact between the fibula (the smaller of the two lower leg bones) and the calcaneum (heel bone), and the dentition.
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Skull of A. malacorhinus On the basis of skull size, the largest species of Aphelops is A. mutilus (which is the largest North American rhinoceros) and the smallest is the type species A. megalodus. A. mutilus has been estimated to have weighed , and A. malacorhinus has been estimated at . Aphelops can be distinguished by other members of the Aceratheriinae by two traits: the arched top of the skull, and the long diastema (gap) between the second incisor (lower tusk) and first premolar. Many other aspects of its anatomy are typical of aceratheriines, including: the absence of a horn on the broad, unfused nasal bones; the reduced premaxilla and lost first incisor; a nasal incision (or notch below the nasal bones) reaching at least the level of the fourth premolar; a triangular-shaped skull when viewed from the rear; narrow zygomatic arches; brachydont or low-crowned teeth without cement; upper molars bearing a fold of enamel known as an anterocrochet; and lower tusks that are subcircular in cross-section.
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Close up of the skull According to Pu et al. 2013, Jianchangosaurus can be distinguished based on the presence of 27 tightly packed maxillary teeth; the dorsal border of the antorbital fenestra is formed by the maxilla, nasal, and lacrimal, but with the majority of the border formed by the nasal; there is no participation of jugal in the margin of the antorbital fenestra; a short diastema is present in the anterior tip of the dentary; dentary teeth have a concave labial surface and a convex lingual surface (this condition is present for all except six anterior teeth); the lack of prominent hypapophyses in the anterior dorsal vertebrae; the anterior caudal centra have an oval cross section and the articular facet is as tall as it is wide; the presence of weakly curved manual unguals with weak flexor tubercles positioned ventral to the articular facet; the ilium is shallow and elongated; the ridge bounding the cuppedicus fossa is confluent with acetabular rim; and there is extensive contact between the pubic apron.
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By the early 21st century, the prevailing theories were that the family was the sister group of either the Marginocephalia (which includes pachycephalosaurids and ceratopsians), or the Cerapoda (the former group plus ornithopods), or as one of the most basal radiations of ornithischians, before the split of the Genasauria (which includes the derived ornithischians). Heterodontosauridae was defined as a clade by Sereno in 1998 and 2005, and the group shares skull features such as three or fewer teeth in each premaxilla, caniniform teeth followed by a diastema, and a jugal horn below the eye. In 2006, palaeontologist Xu Xing and colleagues named the clade Heterodontosauriformes, which included Heterodontosauridae and Marginocephalia, since some features earlier only known from heterodontosaurs were also seen in the basal ceratopsian genus Yinlong. Timelapse video showing the construction of a model built around a skull cast, including musculature Many genera have been referred to Heterodontosauridae since the family was erected, yet Heterodontosaurus remains the most completely known genus, and has functioned as the primary reference point for the group in the palaeontological literature.
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