Macroscelides proboscideus, the short-eared elephant shrew, is one of 15 extant species of the clade Macroscelidea. Elephant shrews are small mammals (head and body length: 95-315 mm) characterized by long slender tails (length: 80-265 mm), long slender legs, and a long, narrow, semi-flexible snout from which the name derives (Nowak, 1991).
All elephant shrews are endemic to Africa. The short-eared elephant shrew is native to Namibia, Cape Province of South Africa, and southern Botswana (Corbet and Hanks, 1968; Nowak, 1991). The fossil record of Macroscelidea also is restricted to Africa and extends back to the Eocene, but with only three pre-Miocene taxa (Butler, 1995).
Recent analyses of molecular data place Macroscelidea in the clade Afrotheria, which also includes aardvarks, elephants, hyraxes, golden moles, tenrecs, and sirenians (Murphy et al., 2001). Within Afrotheria, elephant shrews form a clade with golden moles and tenrecs (Murphy et al., 2001). Morphological data place Macroscelidea as the sister taxon to Glires (rabbits + rodents; Novacek, 1992a, b).
Macroscelides proboscideus is a smallish elephant shrew (head and body length: 104-115 mm; tail length: 115-130 mm) with long pelage that is light gray-brown on the dorsum, yellow-brown on the flanks, and white on the ventrum (Corbet and Hanks, 1968). Diagnostic features of this species include presence of a hallux; having relatively short, round ears; and presence of three pairs of mammae in females (Corbet and Hanks, 1968; Nowak, 1991). The auditory bullae are greatly enlarged with contributions from the mastoid portion of the petrosal, occipital, squamosal, and parietal (Corbet and Hanks, 1968). Dental characters of M. proboscideus that distinguish it from other elephant shrews are presence of two lower molars with hypsodont posterior teeth, three upper incisors, and reduction of the canine (Corbet and Hanks, 1968; Nowak, 1991).
Macrosclides proboscideus inhabits sandy and gravel thornbrush plains and refuges in shallow burrows under bushes (Nowak, 1991:183-184). The short-eared elephant shrew is mainly diurnal but sometimes crepuscular or nocturnal in activity, and it primarily feeds on insects along with roots, tender shoots, and berries (Nowak, 1991:184). This species is mainly solitary in the wild (Nowak, 1991). Young are very precocial at birth, being covered with hair and able to move about soon after they are born (Nowak, 1991). Four species of elephant shrews are listed as either endangered or vulnerable by IUCN, but M. proboscideus is not one of them.
Literature
Butler, P. M. 1995. Fossil Macroscelidea. Mammal Review 25:3-14.
Corbet, G. B., and J. Hanks. 1968. A revision of the elephant-shrews, Family Macroscelididae. Bulletin of the British Museum (Natural History). Zoology 16:47-111.
Murphy, W. J., E. Eizirik, S. J. O’Brien, O. Madsen, M. Scally, C. J. Douady, E. Teeling, O. A. Ryder, M. J. Stanhope, W. W. de Jong, and M. S. Springer. 2001. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science 294:2348-2351.
Novacek, M. J. 1992a. Fossils, topologies, missing data, and the higher level phylogeny of eutherian mammals. Systematic Biology 41:58-73.
Novacek, M. J. 1992b. Mammalian phylogeny: shaking the tree. Nature 356:121-125.
Nowak, R. M. 1991. Walker’s Mammals of the World. Volume 1. Fifth edition. The Johns Hopkins University Press, Baltimore.
Links
Images of Macroscelides proboscideus on Calphotos.com.
Species account of Macroscelides proboscideus on The Animal Diversity Web (The University of Michigan Museum of Zoology).
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