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''Amblysomus'' is a genus of golden moles (also "African golden moles" and "South African golden moles"〔Murray Wrobel: ''Elsevier's Dictionary of Mammals''. Elsevier 2006, ISBN 978-0-444-51877-4.〕) in the golden mole family, Chrysochloridae. It contains the following species: *Fynbos golden mole (''Amblysomus corriae'') *Hottentot golden mole (''Amblysomus hottentotus'') *Marley's golden mole (''Amblysomus marleyi'') *Robust golden mole (''Amblysomus robustus'') *Highveld golden mole (''Amblysomus septentrionalis'') Members of ''Amblysomus'' are distributed in Southern Africa. All five species are found in South Africa with some being found in Swaziland and Lesotho as well. ==Phylogeny and morphology== ''Amblysomus'' is part of the family of golden moles, Chrysochloridae. The order of golden moles and tenrecs, Afrosoricida, is part of Afrotheria, one of the four main divisions of placental mammals, along with elephant shrews, aardvarks, hyraxes, sirenians and elephants. Golden moles are not all golden. Some have black to pale tawny-yellow fur.; the name and family name “Chrysochloridae” (meaning green-gold), refers to the coppery gold, green, purple or bronze sheen of their dense fur. They all have differences in size and color, but have a similar appearance” with compact fusiform or lozenge-shaped bodies, short and powerful forelimbs containing pick-like claws, and no external eyes, ears or tail”. Their fur consists of guard hairs that are moisture repellent. They have a woolly underfur for insulation. Their skin is thick and tough, especially on the head, containing a wedge-shaped muzzle with a leathery nosepad protecting its nostrils. upward thrust of their dorsally-flattened head and powerful down thrusts of the foreclaws help them tunnel through the soil during subsurface foraging. This creates raised visible ridges of soil. Genera Amblysomus and Neamblysomus use the head and webbed hind feet to move soil and evict it on the surface.〔 Similarities to fossorial mammals resulted from ecological convergence, not ancestry. The eyes are vestigial and that is why they are covered by skin. The optic nerve is degenerate because they live underground where there is little use of them. The external ear pinnae are absent as well as the external tail. The body has a streamlined shape which facilitates movement through dense substratum.〔 On the outside, they are similar to other fossorial small mammals, but the golden moles show highly specialized characters like “a unique hyoid-dentary articulation. Some also have hypertrophied malleus bones in the middle ear that permits great sensitivity to underground vibrations and airborne sounds. They have a third bone in the forearm (i.e. ossified tendon) and a reduction of phalanges in the fore- and hindfeet. Muscle arrangements are not paralleled in the Mammalia. Most anatomical specializations shown in extant species are found in 3 fossil species (dating back to the Miocene). Chrysochlorids have been described as "spectacularly autapomorphic" due to how unusual and numerous they are.〔 They are blind, subterranean small mammals〔 with small ears, tails and eyes that are all covered by skin and fur. They have unique cranial and nasal morphology.〔 On their nose is a large leathery pad to help them burrow. They have powerful forearms and claws, but use mainly their snout to burrow. The golden mole thrusts its forearms from under its body to help it burrow deeper into the earth. Both the male and female have a cloaca. They have tabulars in the occipital which is not found in other mammals. Their zygomatic arches form elongations of the maxillae. Their malleus is enlarged and helps in hearing under the ground. Golden moles do not have a fifth finger on their front paws. Instead, they have a huge claw on the third or second finger. Their fur has an iridescent sheen. Their dental formula is 3,1,3,2/3,1,3,2. The first incisor is enlarged. The lateral incisors and first premolars are like canines. The molars are zalmbdodont (have v-shaped crest) like tenrecs. Zalambdodonty has arisen independently. This implies that it is due to morphological convergence, because they are not closely allied to any other family of extant mammals.〔 Studies show that tenrecs and golden moles should be separated from Insectivora and placed in Afrotheria which include the elephant shrews and hyraxes.〔 They share few morphological synapomorphies. Mitochondrial/nuclear gene sequences and rare genomic changes demonstrated that chrysochlorids and tenrecs form their own clade, Afrosoricida (African shrew-like mammals). It contains no soricids (shrews) and is sometimes confused with the shrew subgenus Afrosorex. Alternative names were "Tenrecoidea" and "Tenrecomorpha”. Divergence between golden-moles and tenrecs occurred about 50 million years ago. They are now classified as Chrysochloridea instead of a specialized members of Order Insectivora.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Amblysomus」の詳細全文を読む スポンサード リンク
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