"Animals in space Non-human animals in space originally served to test the survivability of spaceflight, before human spaceflights were attempted. Later, other non-human animals were flown to investigate various biological processes and the effects microgravity and space flight might have on them. Bioastronautics is an area of bioengineering research which spans the study and support of life in space. To date, seven national space programs have flown animals into space: the Soviet Union, the United States, France, Argentina, China, Japan and Iran. A wide variety of non-human animals have been launched into space, including monkeys, dogs, tortoises, and insects. The"
"been documented in this species, including albinism (total lack of pigment), leucism (partial lack of pigment), and melanism (over-pigmentation). It is a diphyodont mammal, meaning that it has two sets of teeth during its lifetime—milk teeth and adult teeth. The dental formula of the milk teeth is for a total of 22 teeth, while that of the adult teeth is for a total of 38 teeth. Newborns (""pups"") are born with 20 milk teeth which becomes 22 when the final upper premolars emerge. Pups begin losing milk teeth once they have reached a body length of ; total loss of"
"may or may not grow in. Among primary teeth, 10 of them are usually found in the maxilla (i.e. upper jaw) and the other 10 in the mandible (i.e. lower jaw). Among permanent teeth, 16 are found in the maxilla and the other 16 in the mandible. Most of the teeth have uniquely distinguishing features. An adult horse has between 36 and 44 teeth. The enamel and dentin layers of horse teeth are intertwined. All horses have 12 premolars, 12 molars, and 12 incisors. Generally, all male equines also have four canine teeth (called tushes) between the molars and incisors."
"Permanent teeth Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibular premolars, two maxillary and two mandibular canines, four maxillary and four mandibular incisors. The first permanent tooth usually appears in the mouth at around six years of age, and the mouth will then be in a transition time with both primary (or deciduous dentition) teeth and permanent teeth during the mixed dentition period until the last primary tooth is"
"is, per pine half; they have five maxilla or four mandibular incisors, one canine, three premolars and four molars, for a total of 50 teeth. Some taxa, such as the opossum, have the original number of teeth. In other groups the number of teeth is reduced. Marsupials in many cases have 40 to 50 teeth, significantly more than placental mammals. The upper jaw has a high number of incisors, up to ten, and they have more molars than premolars. The second set of teeth grows in only at the 3rd premolar: all remaining teeth are already created as permanent teeth."
"between species; they can have from 32 to 42 teeth in total. Unusual for mammals, the permanent dentition in tenrecs tends not to completely erupt until well after adult body size has been reached. This is one of several anatomical features shared by elephants, hyraxes, sengis, and golden moles (but apparently not aardvarks), consistent with their descent from a common ancestor. Tenrecs have a gestation period of 50 to 64 days, and give birth to a number of relatively undeveloped young. While the otter shrews have just two young per litter, the tailless tenrec can have as many as 32,"
"teeth (often referred to as ""milk teeth"", ""baby teeth"" or ""puppy teeth""). The second set is the 42-piece permanent or adult teeth. Sometimes the number of permanent or adult teeth may vary, which is fine as long as they do not cause bad bite. When puppies are born, they have no teeth because milk is the only food they need. The deciduous teeth will grow from the age of 3 to 8 weeks old, in the order of incisors, canine/ fangs and premolars. Yorkie puppies have no molar teeth. Yorkie puppies will start to lose their deciduous or baby teeth"
"for chewing and grinding. Carnivores, on the other hand, have canine teeth to kill prey and to tear meat. Mammals, in general, are diphyodont, meaning that they develop two sets of teeth. In humans, the first set (the ""baby,"" ""milk,"" ""primary"" or ""deciduous"" set) normally starts to appear at about six months of age, although some babies are born with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething and can be painful. Kangaroos, elephants, and manatees are unusual among mammals because they are polyphyodonts. In Aardvarks, teeth lack"
"wear down their teeth by gnawing on various materials. These teeth are used for cutting wood, biting through the skin of fruit, or for defense. The teeth have enamel on the outside and exposed dentin on the inside, so they self-sharpen during gnawing. On the other hand, continually growing molars are found in some rodent species, such as the sibling vole and the guinea pig. There is variation in the dentition of the rodents, but generally, rodents lack canines and premolars, and have a space between their incisors and molars, called the diastema region. An adult horse has between 36"
"suitable for their terrain. Horses are adapted to grazing. In an adult horse, there are 12 incisors at the front of the mouth, adapted to biting off the grass or other vegetation. There are 24 teeth adapted for chewing, the premolars and molars, at the back of the mouth. Stallions and geldings have four additional teeth just behind the incisors, a type of canine teeth called ""tushes"". Some horses, both male and female, will also develop one to four very small vestigial teeth in front of the molars, known as ""wolf"" teeth, which are generally removed because they can interfere"
"by a completely new set of thirty-two adult teeth. In some cases hypodontia or hyperdontia occurs, the latter in cleidocranial dysostosis and Gardner's syndrome. In the hare the anterior incisors are not replaced but the posterior smaller incisors are replaced. Not much is known about the developmental mechanisms regulating diphyodont replacement. The house shrew, ""Suncus murinus"", and the Chinese miniature pig are currently being used to study the diphyodont replacement of the deciduous dentition by replacements and additional permanent teeth. Manatees, elephants and kangaroos differ from most other mammals because they are polyphyodonts. Diphyodont A diphyodont is any animal with"
"and hippopotamuses have a relatively large number of teeth (with some pigs having 44); their dentition is more adapted to a squeezing mastication, which is characteristic of omnivores. Camels and ruminants have fewer teeth; there is often a yawning diastema, a designated gap in the teeth where the molars are aligned for crushing plant matter. The incisors are often reduced in ruminants, and are completely absent in the upper jaw. The canines are enlarged and tusk-like in the Suina, and are used for digging in the ground and for defense. In ruminants, the males' upper canines are enlarged and used"
"mass, found that for placental mammals the bite force at the canines (in Newtons/kilogram of body weight) was greatest in the extinct dire wolf (163), followed among the modern canids by the four hypercarnivores that often prey on animals larger than themselves: the African wild dog (142), the gray wolf (136), the dhole (112), and the dingo (108). The bite force at the carnassials showed a similar trend to the canines. A predator's largest prey size is strongly influenced by its biomechanical limits. Most canids have 42 teeth, with a dental formula of: . The bush dog has only one"
"born with some milk teeth already erupted: canines and incisors. By 9 days old, all the milk teeth have emerged, with a dental formula of and a total of 20 teeth. By 140 days old (4.6 months), all the milk teeth have fallen and been replaced by permanent teeth. The canines are usually replaced first, followed by the premolars, incisors, and then molars. The adult dental formula is for a total of 34 teeth. The occlusal surface of the molars is generally smooth but with longitudinal furrows. Flying foxes have large hearts and a relatively fast heart rate: resting individuals"
"age will have between 36 and 44 teeth. All equines are heterodontous, which means that they have different shaped teeth for different purposes. All horses have twelve incisors at the front of the mouth, used primarily for cutting food, most often grass, whilst grazing. They are also used as part of a horse's attack or defence against predators, or as part of establishing social hierarchy within the herd. Immediately behind the front incisors is the interdental space, where no teeth grow from the gums. This is where the bit is placed, if used, when horses are ridden. Behind the interdental"
"dental formula of adult pigs is , giving a total of 44 teeth. The rear teeth are adapted for crushing. In the male the canine teeth can form tusks, which grow continuously and are sharpened by constantly being ground against each other. Four hoofed toes are on each foot, with the two larger central toes bearing most of the weight, but the outer two also being used in soft ground. Most domestic pigs have rather a bristled sparse hair covering on their skin, although woolly-coated breeds such as the Mangalitsa exist. Pigs possess both apocrine and eccrine sweat glands, although"
"eruption and tooth development. Typically, the mandibular central incisors erupt first, followed by the maxillary central incisors, the mandibular lateral incisors and finally the maxillary laterals. The rest of the primary dentition erupts after the incisors. Apart from the first molars, the incisors are also the first permanent teeth to erupt, following the same order as the primary teeth, among themselves. Among other animals, the number varies from species to species. Opossums have 18, whereas armadillos have none. Cats, dogs, foxes, pigs, and horses have twelve. Rodents have four. Rabbits and hares (lagomorphs) were once considered rodents, but are distinguished"
"teeth. Both baby and adult canines would be present side by side in the mouth for an 11-month period, and the muscles used in making the powerful bite were developed at about one-and-a-half years old as well, eight months earlier than in a modern lion. After ""Smilodon"" turned around 20 months of age, the infant teeth were shed while the adult canines grew at an average growth rate of per month during a 12-month period. They reached their full size at around 3 years of age, later than for modern species of big cat. Juvenile and adolescent ""Smilodon"" specimens are"
"This phenomenon is called hyperdontia and is often erroneously referred to as ""a third set of teeth."" These teeth may erupt into the mouth or remain impacted in the bone. Hyperdontia is often associated with syndromes such as cleft lip and palate, trichorhinophalangeal syndrome, cleidocranial dysplasia, and Gardner's syndrome. Permanent teeth Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibular premolars, two maxillary and two mandibular canines, four maxillary and"
"been abandoned. It has a long and narrow rostrum, which is the projection that forms the snout. The junction between the skull bones turns into bone early on in their age, which makes it difficult to identify their age based on looking at their skull bones. The maxillary only turns into bone in the adults and the roots of the upper molars are exposed in immature shrew-moles. The first upper incisor is flat and it does not have an elongated crown, like shrew do. It has 36 teeth, which consist of incisors, canines, pre-molars, and molars. This mole is often"
"with a total of 36. Its upper incisors are elongated and the incisiform canines barely extend beyond the other teeth. The upper molars are sometimes tricuspid and the lower premolars are relatively simple. Upper and lower molars are quadricuspid. It has relatively large ears often obscured by the fur on side of the head. The nose has a wide internal septum and the nares open laterally. In adults, the pelage of the back can be grey, reddish, or brown. It usually has white or black bands on its forehead. This color pattern found both in young and adults. The ear"
"Adult ""T. liorhinus"" assumes the dental pattern of the four incisors, one canine and six postcanines on each side of the upper jaw. This pattern is reflected in the lower jaw by a dental formula of three incisors, one canine and 7–8 postcanines on each side of the lower jaw. With this formula, one can make a small note that in general, adult Thrinaxodon contained anywhere between 44 and 46 total teeth. Upper incisors in ""T. liorhinus"" assume a backwards directed cusp, and they go from being curved and pointed at their most distal point, and become broader and rounder"
"jaws. On the other hand, the narwhals have a giant unicorn-like tusk, which is a tooth containing millions of sensory pathways and used for sensing during feeding, navigation, and mating. It is the most neurologically complex tooth known. Beaked whales are almost toothless, with only bizarre teeth found in males. These teeth may be used for feeding but also for demonstrating aggression and showmanship. In humans (and most other primates) there are usually 20 primary (""baby"") teeth, 28 to 32 of what's known as ""permanent teeth"", in addition to other four being third molars or wisdom teeth, each of which"
"long snout that is strengthened by a special prenasal bone and by a disk of cartilage at the tip. The snout is used to dig into the soil to find food and is a very acute sense organ. There are four hoofed toes on each foot, with the two larger central toes bearing most of the weight, but the outer two also being used in soft ground. The dental formula of adult pigs is , giving a total of 44 teeth. The rear teeth are adapted for crushing. In the male, the canine teeth form tusks, which grow continuously and"
"these are replaced by larger molars. The new molars shift forward from the back of the jaw as the old wear down. The final set of molars last for about twenty years. Manatees are polyphyodonts with mandibular molars developing separately from the jaw and are encased in a bony shell separated by soft tissue. Walrus tusks are canine teeth that grow continuously throughout life. In dogs, the teeth are less likely than humans to form dental cavities because of the very high pH of dog saliva, which prevents enamel from demineralizing. In Aardvarks, teeth lack enamel and have many pulp"
"individual ages. A fox's dentition, like all other canids, is I 3/3, C 1/1, PM 4/4, M 3/2 = 42. (Bat-eared foxes have six extra molars, totaling in 48 teeth.) Foxes have pronounced carnassial pairs, which is characteristic of a carnivore. These pairs consist of the upper premolar and the lower first molar, and work together to shear tough material like flesh. Foxes' canines are pronounced, also characteristic of a carnivore, and are excellent in gripping prey. In the wild, the typical lifespan of a fox is one to three years, although individuals may live up to ten years. Unlike"
"rate of growth and mature weight is a heritable trait that is often selected for in breeding. Ewes typically weigh between , and rams between . When all deciduous teeth have erupted, the sheep has 20 teeth. Mature sheep have 32 teeth. As with other ruminants, the front teeth in the lower jaw bite against a hard, toothless pad in the upper jaw. These are used to pick off vegetation, then the rear teeth grind it before it is swallowed. There are eight lower front teeth in ruminants, but there is some disagreement as to whether these are eight incisors,"
"in the upper jaw, so only the upper teeth are visible when the mouth is closed. The teeth on the lower jaw of a crocodile fit into grooves on the outside of the top jaw making both the upper and lower teeth visible when the mouth is closed. Crocodilians are polyphyodonts and able to replace each of their approximately 80 teeth up to 50 times in their 35 to 75-year lifespan. They are the only non-mammalian vertebrates with tooth sockets. Next to each full-grown tooth there is a small replacement tooth and an odontogenic stem cell in the dental lamina"
"non-sternal pairs of ribs. The spinal cord is nearly long; it terminates in the second and third sacral vertebra. The fibula is reduced to a malleolar bone. The dromedary is a digitigrade animal; it walks on its toes, which are known as digits. It lacks the second and fifth digits. The front feet are wide and long; they are larger than the hind feet, which measure wide and long. The dromedary has 22 milk teeth, which are eventually replaced by 34 permanent teeth. The dental formula for permanent dentition is , and for milk dentition. In the juvenile, the lower"
"Most ecosystems with a generous supply of termites have a fairly large creature with powerful forelimbs bearing heavy claws. Numbats are not large, and they have five toes on the fore feet, and four on the hind feet. However, like other mammals that eat termites or ants, the numbat has a degenerate jaw with up to 50 very small, nonfunctional teeth, and although it is able to chew, rarely does so, because of the soft nature of its diet. Uniquely among terrestrial mammals, an additional cheek tooth is located between the premolars and molars; whether this represents a supernumerary molar"
"first week of their life from their mother’s nutrient-rich milk. Muskox - Muskoxen have large horns and thick, hard skulls. When threatened by bears or wolves a herd of muskoxen will gather in a circle with their young in the middle. They will then take turns charging their attacker. Narwhal - The narwhal has only two teeth. One stays small while one (usually the left tooth) grows up to nine feet long through the narwhal’s upper lip. In most cases, only male narwhals grow the giant tusk. Orca - Orcas travel in groups composed of ten to fifty individuals. These"
"any known placental land mammal was 48, with a formula of . However, no existing (or extant) placental mammal has this number. In extant placental mammals, the maximum dental formula is: . Mammal teeth are usually symmetrical, but not always. For example, the aye-aye has a formula of , demonstrating the need for both upper and lower quadrant counts. Teeth are numbered starting at 1 in each group. Thus the human teeth are I1, I2, C1, P3, P4, M1, M2, and M3. (See next paragraph for premolar naming etymology.) In humans, the third molar is known as the wisdom tooth,"
"Horse teeth Horse teeth refers to the dentition of equine species, including horses and donkeys. Equines are both heterodontous and diphyodontous, which means that they have teeth in more than one shape (there are up to five shapes of tooth in a horse's mouth), and have two successive sets of teeth, the deciduous (""baby teeth"") and permanent sets. As grazing animals, good dentition is essential to survival, and continued grazing creates specific patterns of wear, which can be used along with patterns of eruption to estimate the age of the horse. A fully developed horse of around five years of"