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Hyracotherium
''Hyracotherium'' ( ; "hyrax-like beast") is an extinct genus of very small (about 60 cm in length) perissodactyl ungulates that was found in the London Clay formation. This small, fox-sized animal was once considered to be the earliest known member of Equidae before the type species, ''H. leporinum'', was reclassified as a palaeothere, a perissodactyl family basal to both horses and brontotheres. The remaining species are now thought to belong to different genera, such as ''Eohippus'', which had previously been synonymised with ''Hyracotherium''. Description ''Hyracotherium'' averaged 78 cm (2.5 feet) in length and weighed about 9 kg (20 pounds). 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. Although it had low-crowned teeth, the beginnings of the characteristic horse-like ridges on the molars can be seen. ''Hyracotherium'' is believed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eohippus
''Eohippus'' is an extinct genus of small equid ungulates. The only species is ''E. angustidens'', which was long considered a species of ''Hyracotherium''. Its remains have been identified in North America and date to the Early Eocene (Ypresian stage). Discovery In 1876, Othniel C. Marsh described a skeleton as ''Eohippus validus'', from el, ἠώς (, 'dawn') and (, 'horse'), meaning 'dawn horse'. Its similarities with fossils described by Richard Owen were formally pointed out in a 1932 paper by Clive Forster Cooper. ''E. validus'' was moved to the genus ''Hyracotherium'', which had priority as the name for the genus, with ''Eohippus'' becoming a junior synonym of that genus. ''Hyracotherium'' was recently found to be a paraphyletic group of species, and the genus now includes only ''H. leporinum''. ''E. validus'' was found to be identical to an earlier-named species, ''Orohippus angustidens'' Cope, 1875, and the resulting binomial is thus ''Eohippus angustidens''. Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sifrhippus
''Sifrhippus'' is an extinct genus of equid containing the species ''S. sandrae''. ''Sifrhippus'' is the oldest known equid, living during the early Eocene. Its fossils were discovered in the Bighorn Basin of Wyoming. Description ''Sifrhippus'' looked similar to modern horses, but were more slender and much smaller. Individuals likely weighed between ; the size variance, according to one theory, depended on the warmth of the climate. Taxonomy ''Sifrhippus sandrae'' is referred to in earlier literature as ''Hyracotherium sandrae'', but Froehlich, arguing that the traditional genus ''Hyracotherium'' was not monophyletic, reassigned many of its species to other genera. Froehlich gave ''H. sandrae'' the new generic name ''Sifrhippus'', derived from the Arabic '' صِفْر'' (''ṣifr''), "zero", and Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arenahippus
''Sifrhippus'' is an extinct genus of equidae, equid containing the species ''S. sandrae''. ''Sifrhippus'' is the oldest known equid, living during the early Eocene. Its fossils were discovered in the Bighorn Basin of Wyoming. Description ''Sifrhippus'' looked similar to modern horses, but were more slender and much smaller. Individuals likely weighed between ; the size variance, according to one theory, depended on the warmth of the climate. Taxonomy ''Sifrhippus sandrae'' is referred to in earlier literature as ''Hyracotherium sandrae'', but Froehlich, arguing that the traditional genus ''Hyracotherium'' was not monophyletic, reassigned many of its species to other genera. Froehlich gave ''H. sandrae'' the new genus, generic name ''Sifrhippus'', derived from the Arabic language, Arabic ''wikt:صِفْر, صِفْر'' (''ṣifr''), "zero", and Greek language, Greek ''wikt:ἵππος, ἵππος'' (''híppos''), "horse". Since Froehlich's reorganization of ''Hyracotherium'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protorohippus
''Protorohippus'' (Latin: "before" (pro), + Greek: "mountain" (oros), "horse" (hippos)) is an extinct equid that lived in the Eocene of North America. image:F John Series 2 Protorohippus card 5.jpg, left, Restoration See also * Evolution of the horse References Eocene horses Eocene odd-toed ungulates Prehistoric placental genera Eocene mammals of North America {{horse-stub ... [...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, 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, as this term is used to describe 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 predators, and po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equidae
Equidae (sometimes known as the horse family) is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. All extant species are in the genus '' Equus'', which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families. The term equid refers to any member of this family, including any equine. Evolution The oldest known fossils assigned to Equidae were found in North America, and date from the early Eocene epoch, 54 million years ago. They were once assigned to the genus ''Hyracotherium'', but the type species of that genus is now regarded as a palaeothere. The other species have been split off into different genera. These early equids were fox-sized animals with three toes on the hind feet, and four on the front feet. They were herbivorous browsers on relatively soft plants, and already adapte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perissodactyl
Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) or one (equines, third toe) of the five original toes. The non-weight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, the even-toed ungulates bear most of their weight equally on four or two (an even number) of the five toes: their third and fourth toes. Another difference between the two is that odd-toed ungulates digest plant cellulose in their intestines rather than in one or more stomach chambers as even-toed ungulates, with the exception of Suina, do. The order includes about 17 species divided into three families: Equidae (horses, asses, and zebras), Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). Despite their very different appearances, they were recognized as related families in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, camels, sheep, deer, and hippopotamuses. Cetaceans such as whales, dolphins, and porpoises are also classified as even-toed ungulates, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. The term means, roughly, "being hoofed" or "hoofed animal". As a descriptive term, "ungulate" normally excludes cetaceans as they do not possess most of the typical morphological characteristics of other ungulates, but recent discoveries indicate that they were also descended from early artiodactyls. Ungulates are typically herbivorous and many employ specialized gut bacteria to allow them to digest cellulose. Some modern species, such as pigs, are omnivorous, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeothere
Palaeotheriidae is an extinct family of herbivorous perissodactyl mammals related to equids. They ranged across Europe and Asia from the Eocene through to the early Oligocene 55–33 Ma, existing for approximately . Living in dense forests, they ate soft leaves, shoots, berries, and leaf matter picked up from the forest floor. Morphology Palaeothere sizes ranged from at the shoulder, and weighed an estimated .S. Legendre. 1988. Les communautes de mammiferes du Paleogene (Eocene superieur et Oligocene) d'Europe occidentale: structure, milieux et evolution. Ph.D. thesis, Universite des Sciences et Techniques du Languedoc, Montpellier, France. 2 volumes. 1-265 Extinction Evidence suggests that the palaeotheriidae went extinct in Eurasia during the Early Oligocene, approximately 33 Ma, as part of a faunal turnover event known as the Grande Coupure. The Eocene-Oligocene transition marked a significant global cooling event caused by the onset of Antarctic glaciatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clive Forster Cooper
Sir Clive Forster Cooper, FRS (3 April 1880 – 23 August 1947) was an English palaeontologist and Director of the Cambridge University Museum of Zoology and Natural History Museum in London. He was the first to describe ''Paraceratherium'', also commonly known as ''Indricotherium'' or ''Baluchitherium'', the largest known land mammal. Early life He was born on 3 April 1880 in Hampstead, London, the second child and only son of John Forster Cooper and his wife Mary Emily Miley. His maternal grandfather, Miles Miley, was an amateur botanist and naturalist, and encouraged Clive Forster-Cooper in his interest in natural history. He was educated at Summer Fields School, Oxford, Rugby School.'Forster-Cooper, Sir Clive', in ''Who Was Who'' In 1897 he went up to Trinity College, Cambridge, and took a BA in 1901 and MA in 1904. Early career In 1900, Forster Cooper travelled with John Stanley Gardiner to the Maldive and Laccadive Islands to undertake collections and study the format ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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