Elephant shrew

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Elephant shrews[1]
Fossil range: Early Oligocene to Recent[2]
Short-eared Elephant Shrew(Macroscelides proboscideus)
Short-eared Elephant Shrew
(Macroscelides proboscideus)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Eutheria
Superorder: Afrotheria
Order: Macroscelidea
Butler, 1956
Family: Macroscelididae
Bonaparte, 1838
Genera

Rhynchocyon
Petrodromus
Macroscelides
Elephantulus


Elephant shrews or jumping shrews are small insectivorous mammals native to Africa, belonging to the Macroscelididae family, in the order Macroscelidea. Their traditional common English name comes from a fancied resemblance between their long noses and the trunk of an elephant, and an assumed relationship with the true shrews (family Soricidae) in the order Insectivora. As it has become plain that the elephant shrews are unrelated to the shrews, some people[attribution needed] prefer to call them sengis, a term derived from the Bantu languages of Africa.

They are widely distributed across the southern part of Africa, and although common nowhere, can be found in almost any type of habitat, from the Namib Desert to boulder-strewn outcrops in South Africa to thick forest. One species, the North African Elephant Shrew, remains in the semi-arid, mountainous country in the far north-west of the continent.

Characteristics

Elephant shrews vary in size from about 100 mm to almost 300 mm, from just under 50 g to over 500 g. The Short-eared Elephant Shrew has an average size of 150 millimetres (5.905511805 in). All are quadrupedal with mouse-like tails, and rather long legs for their size, and although the size of the trunk varies from one species to another, all are able to twist it about in search of food. Their life span is about two or three years. Their diet is largely insects and other small creatures, particularly beetles, spiders, worms, ants, and termites, mostly gleaned from leaf litter, but they also take seeds and some green shoots. They have large canine teeth, and also high-crowned cheek teeth like those of ungulates[3]. Their dental formula is:

1-3.1.4.2
3.1.4.2-3

Although mostly diurnal and very active, they are difficult to trap and very seldom seen: elephant shrews are wary, well camouflaged, and adept at dashing away from threats. Several species make a series of cleared pathways through the undergrowth and spend their day patrolling them for insect life: if disturbed, the pathway provides an obstacle-free escape route.

Elephant shrews are not highly social animals, but many live in mongamous pairs, which share and defend a home territory, which they mark using scent glands[3]. The Rhynchocyon species also dig small conical holes in the soil, bandicoot style, but others may use natural crevices, or make leaf nests.

Females give birth to litters of one or three young several times a year, after a gestation period varying from 45 to 60 days. The young are born relatively well developed, but remain in the nest for several days before venturing outside[3].

Classification

In the past, elephant shrews have been classified with the shrews and hedgehogs as part of the Insectivora; regarded as distant relatives of the ungulates; grouped with the treeshrews; and lumped in with the hares and rabbits in the Lagomorpha. Recent molecular evidence, however, strongly supports a superorder Afrotheria which unites tenrecs, and golden moles with certain ungulates or mammals that were previously presumed to be ungulates, including hyraxes, sirenians, aardvarks and elephants, as well as the elephant shrews.

A number of fossil species are also known, all of them from Africa. Some, such as Myohyrax, were so similar to hyraxes that they were initially misidentified as belonging to that group, while others, such as Mylomygale were relatively rodent-like. These unusual forms all died out by the Pleistocene[2].

File:Elephantshrew.jpg
An elephant shrew from Frankfurt Zoo.

There are 16 species of elephant shrew in four genera, two of which are monotypic.

External links

References

  1. 1.0 1.1 Template:MSW3 Schlitter
  2. 2.0 2.1 Savage, RJG, & Long, MR (1986). Mammal Evolution: an illustrated guide. New York: Facts on File. p. 54. ISBN 0-8160-1194-X.
  3. 3.0 3.1 3.2 Rathbun, Galen B. (1984). Macdonald, D., ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 730–733. ISBN 0-87196-871-1.
  4. AFP: Shrew's who: New mammal enters the book of life


Murata Y, Nikaido M, Sasaki T, Cao Y, Fukumoto Y, Hasegawa M, Okada N. Afrotherian phylogeny as inferred from complete mitochondrial genomes. Mol Phylogenet Evol. 2003 Aug;28(2):253-60.

Murphy WJ, Eizirik E, Johnson WE, Zhang YP, Ryder OA, O'Brien SJ. Molecular phylogenetics and the origins of placental mammals. Nature. 2001 Feb 1;409(6820):614-8.

Tabuce R, Marivaux L, Adaci M, Bensalah M, Hartenberger JL, Mahboubi M, Mebrouk F, Tafforeau P, Jaeger JJ. Early Tertiary mammals from North Africa reinforce the molecular Afrotheria clade. Proc Biol Sci. 2007 May 7;274(1614):1159-66.

Template:Macroscelidea

ca:Musaranya elefant cs:Bércouni da:Springspidsmus de:Rüsselspringer eo:Makrosceliduloj it:Macroscelididae li:Olifantsspitsmoes hu:Elefántcickány-félék mt:Macroscelididae nl:Springspitsmuizen no:Springspissmus fi:Norsupäästäiset sv:Springnäbbmöss th:หนูผีช้าง



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