Cladus: Eukaryota Name Hyracoidea Huxley, 1869 Synonyms * Hyracea Haeckel, 1895 References * Hyracoidea on Mammal species of the World. Vernacular names --------------- A hyrax (from Greek ὕραξ yrax "shrewmouse") is any of four species of fairly small, thickset, herbivorous mammals in the order Hyracoidea: The Rock Hyrax Procavia capensis, the Yellow-spotted Rock Hyrax Heterohyrax brucei, the Western Tree Hyrax Dendrohyrax dorsalis, and the Southern Tree Hyrax, Dendrohyrax arboreus. They live in Africa and the Middle East. Hyraxes are well-furred rotund creatures with a short tail. Most measure between 30–70 cm long and weigh between 2–5 kg. Unlike the even-toed ungulates and some of the macropods, hyraxes do not chew cud to help extract nutrients from coarse, low-grade leaves and grasses. They do, however, have complex, multi-chambered stomachs that allow symbiotic bacteria to break down tough plant materials, and their overall ability to digest fibre is similar to that of the ungulates. They will show antagonistic behavior, such as making chewing motions, when they feel threatened. This behavior is often confused with chewing cud.[1] There are reports that the Hyrax can chew regurgitated food, however, this is infrequent and they do not do this for nutrition or as part of their diet.[2] Hyraxes inhabit rocky terrain across sub-Saharan Africa and the Middle East. Their feet have rubbery pads with numerous sweat glands, which help the animal maintain its grip when moving fast up steep rocky surfaces. They also have efficient kidneys, retaining water so that they can survive in arid environments. Female hyraxes give birth to up to four young after a gestation period of between seven and eight months, depending on the species. The young are weaned at one to five months of age, and reach sexual maturity at sixteen to seventeen months. Male hyraxes have testicles that do not reside in the scrotum, much like elephants, manatees and dugongs. Female hyraxes have a pair of teats near their shoulders as well as four teats in their groin. Hyraxes live in small family groups, dominated by a single male who aggressively defends the territory from rivals. Where there is abundant living space, the male may dominate multiple groups of females, each with their own range. The remaining males live solitary lives, often on the periphery of areas controlled by larger males, and mate only with younger females.[3] Historical accounts Phoenician sailors visiting the coast of Spain circa 1100s BC, mistaking the European rabbit for the rock hyrax Procavia capensis from their native homeland, gave it the name i-shepan-ham. A theory exists that an adaptation and/or corruption of this name, used by the Romans, became Hispania, leading to English Spain and Spanish España --- although this theory is somewhat controversial.[6] Evolution All modern hyraxes are members of the family Procaviidae (the only living family within the Hyracoidea) and are found only in Africa and the Middle East. In the past, however, hyraxes were more diverse and widespread. The order first appears in the fossil record over 40 million years ago, and for many millions of years hyraxes were the primary terrestrial herbivore in Africa, just as odd-toed ungulates were in the Americas. There were many different species, the largest of them about the weight of a small horse, the smallest the size of a mouse. During the Miocene, however, competition from the newly-developed bovids—very efficient grazers and browsers—pushed the hyraxes out of the prime territory and into marginal niches. Nevertheless, the order remained widespread, diverse and successful as late as the end of the Pliocene (about two million years ago) with representatives throughout most of Africa, Europe and Asia. The descendants of the giant hyracoids evolved in different ways. Some became smaller, and gave rise to the modern hyrax family. Others appear to have taken to the water (perhaps like the modern capybara), and ultimately gave rise to the elephant family, and perhaps also the Sirenians (dugongs and manatees). DNA evidence supports this hypothesis, and the small modern hyraxes share numerous features with elephants, such as toenails, excellent hearing, sensitive pads on their feet, small tusks, good memory, high brain functions compared to other similar mammals, and the shape of some of their bones.[7] Hyraxes are sometimes described as being the closest living relative to the elephant.[8] Although relatively closely related, not all scientists support the proposal that hyraxes are the closest living relative of the elephant. Recent morphological and molecular based classifications reveal the Sirenians to be the closest living relatives of elephants, while hyraxes are closely related but form an outgroup to the assemblage of elephants, sirenians, and extinct orders like Embrithopoda and Desmostylia.[9] The Archaeohyracidae extinct family of meridiungulata comprising four genera of notoungulate mammals known from the Paleocene through the Oligocene of South America[10]. is a resemblable group, not related with the true hyraxes. Many of this false hyrax have hyrax related names by this topic: Acoelohyrax, Archaeohyrax, Eohyrax, Protarchaeohyrax, Pseudhyrax... Scientists have recently reduced the number of distinct species of hyrax recognized. As recently as 1995 there were eleven or more recognized species; only four are recognized today. The remaining species are regarded as subspecies of the remaining four. There are over 50 recognized subspecies and species, many of which are considered highly endangered.[11] References Source: Wikispecies, Wikipedia: All text is available under the terms of the GNU Free Documentation License |
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