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Tenrecs
A tenrec is any species of mammal within the afrotherian family Tenrecidae endemic to Madagascar. Tenrecs are wildly diverse; as a result of convergent evolution some resemble hedgehogs, shrews, opossums, rats, and mice. They occupy aquatic, arboreal, terrestrial and fossorial environments. Some of these species, including the greater hedgehog tenrec, can be found in the Madagascar dry deciduous forests. However, the speciation rate in this group has been higher in humid forests. All tenrecs are believed to descend from a common ancestor that lived 29–37 million years ( Ma) ago after rafting over from Africa. The split from their closest relatives, African otter shrews, is estimated to have occurred about 47–53 Ma ago. Etymology The word ''tenrec'' is borrowed, via French, from the Malagasy word (variant of ), which refers to the Tailless tenrec (''Tenrec ecaudatus''); the Malagasy word is related to . Evolution Tenrecs are believed to have evolved from a single s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afrotheria
Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also known as sengis), tenrecs, aardvarks, hyraxes, elephants, sea cows, and several extinct clades. Most groups of afrotheres share little or no superficial resemblance, and their similarities have only become known in recent times because of genetics and molecular studies. Many afrothere groups are found mostly or exclusively in Africa, reflecting the fact that Africa was an island continent from the Cretaceous until the early Miocene around 20 million years ago, when Afro-Arabia collided with Eurasia. Because Africa was isolated by water, Laurasian groups of mammals such as insectivores, rodents, lagomorphs, carnivorans and ungulates could not reach Africa for much of the early to mid-Cenozoic. Instead, the niches occupied by those groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Hedgehog Tenrec
The greater hedgehog tenrec (''Setifer setosus''), also known as the large Madagascar hedgehog or sokina, is a species of mammal in the family Tenrecidae. It is endemic to Madagascar. Its natural habitats are subtropical or tropical forests, shrubland and grassland, savanna, rural gardens, and urban areas. It is the only species in the genus ''Setifer''. Despite the close resemblance, it is not closely related to hedgehogs. Similarly to hedgehogs, neoplasia is common within the species and plays a significant role in morbidity and mortality. Distribution and Habitat Greater hedgehog tenrecs are found throughout the island of Madagascar and are endemic to this island. The island of Madagascar ranges from sea level to 2,250 meters above sea level, and Setifer setosus is found throughout the island, with the exception of wetlands and marshes. Greater hedgehog tenrecs are seen in urban areas and even in areas with extensive human disturbance. The prime habitat for greater hedgehog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otter Shrew
Potamogalidae is the family of "otter shrews", a group of semiaquatic riverine afrotherian mammals indigenous to sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar, from which they are thought to have split about 47–53 million years ago. They were formerly considered a subfamily of Tenrecidae. All otter shrews are carnivorous, preying on any aquatic animal they can find with their sensitive whiskers, particurally insects. As their common name suggests, they bear a strong, but superficial resemblance to true otters to which they are not closely related, nor are they closely related to true shrews. They move through the water by undulating their tail in a side-to-side motion similar to the motions made by a crocodile swimming. Morphology Otter shrews have small eyes and ears, consistent with the features of nearly all shrews. They have a broad, flat, muzzle that is substantially covered with sensetive whiskers and ends in a leathery pad. The margins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Dispersal
Oceanic dispersal is a type of biological dispersal that occurs when terrestrial organisms transfer from one land mass to another by way of a sea crossing. Island hopping is the crossing of an ocean by a series of shorter journeys between islands, as opposed to a single journey directly to the destination. Often this occurs via large rafts of floating vegetation such as are sometimes seen floating down major rivers in the tropics and washing out to sea, occasionally with animals trapped on them. Dispersal via such a raft is sometimes referred to as a rafting event. Colonization of land masses by plants can also occur via long-distance oceanic dispersal of floating seeds. History Rafting has played an important role in the colonization of isolated land masses by mammals. Prominent examples include Madagascar, which has been isolated for ~120 million years ( Ma), and South America, which was isolated for much of the Cenozoic. Both land masses, for example, appear to have receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Mole
Golden moles are small insectivorous burrowing mammals endemic to Sub-Saharan Africa. They comprise the family Chrysochloridae and as such they are taxonomically distinct from the true moles, family Talpidae, and other mole-like families, all of which, to various degrees, they resemble as a result of evolutionary convergence. There are 21 species. Some (e.g., ''Chrysochloris asiatica'', ''Amblysomus hottentotus'') are relatively common, whereas others (e.g., species of ''Chrysospalax'', ''Cryptochloris'', ''Neamblysomus'') are rare and endangered. Characteristics and affinities Like most burrowing mammals with similar habits, the Chrysochloridae have short legs with powerful digging claws, very dense fur that repels dirt and moisture, and toughened skin, particularly on the head. Their eyes are non-functional and covered with furred skin. The external ears are just tiny openings. In particular, golden moles bear a remarkable resemblance to the marsupial moles of Australia, fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tenrecinae
Tenrecinae is a tenrec subfamily endemic to the island of Madagascar. It contains the largest species in the family, ''Tenrec ecaudatus''. All members of the genus possess spines, analogous to those of hedgehogs, for defense against predators. Tenrecinae is thought to have split from the lineages of all other extant tenrecs about 36 million years ( Ma) ago. The deepest phylogenetic split within the subfamily, that between two clades composed of ''Echinops'' plus ''Setifer'' and ''Hemicentetes'' plus ''Tenrec'', is thought to have occurred about 26 Ma ago. In turn, ''Hemicentetes'' is thought to have diverged from ''Tenrec'' about 16 Ma ago, and ''Echinops'' from ''Setifer'' about 10 Ma ago. Extant species Subfamily Tenrecinae * Tribe: Setiferini ** Genus ''Echinops'' *** Lesser hedgehog tenrec (''E. telfairi'') ** Genus '' Setifer'' *** Greater hedgehog tenrec (''S. setosus'') * Tribe: Tenrecini ** Genus '' Hemicentetes'' *** Highland streaked tenrec (''H. nigriceps'') *** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla ( hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla (cetaceans and even-toed ungulates), and the Carnivora ( cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, toget ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar Dry Deciduous Forests
The Madagascar dry deciduous forests represent a tropical dry forest ecoregion situated in the western and northern part of Madagascar. The area has high numbers of endemic plant and animal species but has suffered large-scale clearance for agriculture. They are among the world's richest and most distinctive dry forests and included in the Global 200 ecoregions by the World Wide Fund. The area is also home to distinctive limestone karst formations known as tsingy, including the World Heritage Site of Bemaraha. Geography There are two separate areas within the ecoregion: the western side of Madagascar from the Ampasindava peninsula in the north to Belo-sur-Tsiribihina and Maromandia in the south (this is most of Mahajanga Province); and the northern tip of the island (apart from the high areas of Amber Mountain). Geological substrate is varied and includes the tsingy limestone massifs. These dry deciduous forests span the coastal plain with its limestone plateaus emanatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar Lowland Forests
The Madagascar lowland forests or Madagascar humid forests are a tropical moist broadleaf forest ecoregion found on the eastern coast of the island of Madagascar, home to a plant and animal mix that is 80 to 90% endemic, with the forests of the eastern plain being a particularly important location of this endemism. They are included in the Global 200 list of outstanding ecoregions. Geography The ecoregion constitutes a narrow strip of lowland forests between Madagascar's east coast and the mountainous central highlands, from sea level to elevation. It covers an area of approximately . The ecoregion is under the direct influence of the oceanic trade winds, which maintain a warm, humid climate; rainfall is above 2,000 mm per year and can reach up to 6,000 mm on the Masoala peninsula. The lowland forests extend from Marojejy in the north to the southeast corner of the island. At the northern edge of ecoregion around Vohemar, the moist forests transition to the drier Madagascar dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaannum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mean yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailless Tenrec
The tailless tenrec (''Tenrec ecaudatus''), also known as the common tenrec, is a species of mammal in the family Tenrecidae. It is the only member of the genus ''Tenrec''. Native to Madagascar, it is also found in the Comoros, Mauritius, Réunion, and Seychelles, where it has been introduced. Its natural habitats are subtropical or tropical forest, grassland, and shrubland, savanna, arable land, pastures, plantations, rural gardens, and urban areas. The tailless tenrec is the largest species of the tenrec family, Tenrecidae. It is in length and weighs up to . It has medium-sized, coarse grey to reddish-grey fur and long, sharp spines along its body. This animal is omnivorous, with a diet consisting of invertebrates and animals such as frogs and mice, as well as leaves. If threatened, this tenrec will scream, erect its spiny hairs to a crest, jump, buck and bite. It shelters in a nest of grass and leaves under a rock, log or bush by day. It gives birth to a litter of as many as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 '' Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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