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Hipparion Rocinantis
''Hipparion'' is an Extinction, extinct genus of three-toed, medium-sized equine belonging to the extinct Tribe (biology), tribe Hipparionini, which lived about 10-5 million years ago. While the genus formerly included most hipparionines, the genus is now more narrowly defined as hipparionines from North Africa spanning the Late Miocene. ''Hipparion'' was a mixed-feeder who ate mostly grass, and lived in the savannah biome. ''Hipparion'' evolved from ''Cormohipparion'', and went extinct due to environmental changes like cooling climates and decreasing Atmosphere, atmospheric carbon dioxide levels. Taxonomy "Hipparion" in sensu lato The genus "Hipparion" was used for over a century as a form classification to describe over a hundred species of Holarctic realm, Holartic hipparionines from the Pliocene and Miocene eras that had three toes and isolated protocones''.'' Since then, groups such as the genera ''Cormohipparion'' ''and Neohipparion'' were proposed to further sort these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Natural History Museum Of China
The National Natural History Museum of China (NNHM; ), previously the Beijing Museum of Natural History, is a municipal public natural history museum in Dongcheng, Beijing, Dongcheng, Beijing, China. It is affiliated with the Beijing Academy of Science and Technology under the Beijing Municipal People's Government. The museum was established as the national Central Museum of Natural History by the Ministry of Culture and Tourism (China), Central Ministry of Culture and the Chinese Academy of Sciences in 1951. In 1962, during the Great Leap Forward period, the museum was transferred to the city government of Beijing and was renamed the Beijing Museum of Natural History. Initially affiliated with the Beijing Municipal Culture Bureau, the museum then came under the purview of the Beijing Municipal Science and Technology Bureau in 1975, and later, the Beijing Academy of Science and Technology in 1985. In January 2023, after receiving an approval reply from the Central Institutional Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neohipparion
''Neohipparion'' (Greek: "new" (neos), "pony" (hipparion)) is an extinction, extinct genus of equid, from the Neogene (Miocene to Pliocene) of North America and Central America. Fossils of this horse have been found in Texas, Florida, Kansas, South Dakota, Montana, Nevada, Alabama, Oregon, and Mexico. This prehistoric species of equid grew up to lengths of long. In Florida, Neohipparion lived in a Savanna, savanna environment during the dry season but moved to a wet environment when it came time to mate. The average age of death for a newborn colt was 3.5 years, with a juvenile mortality rate of 64% during its first 2 years of existence. Its diet consisted of Poaceae, grasses, C3 plants, C3 and C4 plants. Δ13C, δ13C values from ‘’N. eurystyle’’ fossils found in Florida indicate that it fed almost exclusively on C4 grasses. References Miocene horses Pliocene horses Prehistoric placental genera Miocene mammals of North America Pliocene mammals of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown (tooth)
In dentistry, the crown is the visible part of the tooth above the gingival margin and is an essential component of dental anatomy. Covered by Tooth enamel, enamel, the crown plays a crucial role in cutting, tearing, and grinding food. Its shape and structure vary depending on the type and function of the tooth (incisors, Canine tooth, canines, premolars, or Molar (tooth), molars), and differ between Deciduous teeth, primary dentition and Permanent teeth, permanent dentition. The crown also contributes to facial aesthetics, speech, and oral health. Anatomical crown vs clinical crown The anatomical crown refers to the portion of the tooth covered by enamel, regardless of whether it is visible. The clinical crown is the part of the tooth that is visible in the mouth. In a healthy young adult, the gums typically follow the contour where enamel meets the root, so the clinical and anatomical crowns are similar in size. However, with age or periodontal disease, this may change. Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypsodont
Hypsodont is a pattern of dentition characterized by with high crowns, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritty, fibrous material. The opposite condition is called brachydont. Evolution Since the morphology of the hypsodont tooth is suited to a more abrasive diet, hypsodonty was thought to have evolved concurrently with the spread of grasslands. Grass contains phytoliths, silica-rich granules, which wear away dental tissue more quickly. Analysis has shown, however, that the development of this morphology is out of sync with the spread and flourishing of grasslands. Instead, the ingestion of grit and soil is hypothesized to be the primary driver of hypsodonty, a hypothesis termed the grit, not grass hypothesis. Morphology Hypsodont dentition is characterized by: * high-crowned teeth * A rough, flattish occlusal surface adapted for crushing and grinding * Cementum both ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoof
The hoof (: hooves) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering. Artiodactyls are even-toed ungulates, species whose feet have an even number of digits; the ruminants with two digits are the most numerous, e.g. giraffe, deer, bison, cattle, goats, gazelles, pigs, and sheep. The feet of perissodactyl mammals have an odd number of toes, e.g. the horse, the rhinoceros, and the tapir. Although hooves are limb structures primarily found in placental mammals, hadrosaurs such as '' Edmontosaurus'' possessed hoofed forelimbs. The marsupial '' Chaeropus'' also had hooves. Description The hoof surrounds the distal end of the second phalanx, the distal phalanx, and the navicular bone. The hoof consists of the hoof wall, the bars of the hoof, the sole and frog and soft tissue shock absorption structures. The weight of the animal is normally borne by both the sole and the edge of the hoof wall. Hooves perform man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestigial Organ
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species. Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tridactyl
In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. The term is derived from the Greek word () meaning "finger." Sometimes the suffix "-dactylia" is used. The derived adjectives end with "-dactyl" or "-dactylous." As a normal feature Pentadactyly Pentadactyly (from Greek "five") is the condition of having five digits on each limb. It is traditionally believed that all living tetrapods are descended from an ancestor with a pentadactyl limb, although many species have now lost or transformed some or all of their digits by the process of evolution. However, this viewpoint was challenged by Stephen Jay Gould in his 1991 essay "Eight (or Fewer) Little Piggies," where he pointed out polydactyly in early tetrapods and described the specializations of digit reduction. Despite the individual variations listed below, the relationship is to the original five-digit model. In reptiles, the limbs are pentadacty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, '' Eohippus'', into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE in Central Asia, and their domestication is believed to have been widespread by 3000 BCE. Horses in the subspecies ''caballus'' are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, which are horses that have never been domesticated. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior. Horses are adapted to run, allowing them to quickly escape predator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Hipparion In Haining Museum 02 2014-08
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of ''Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. The ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
