Pedetidaespringhare

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The springhaas, the only member of this family, is a peculiar, large, rabbit- or kangaroo-like rodent inhabiting arid lands of southern Africa. These animals, which weigh up to about 4 kg, have enormously enlarged hind feet and a long, heavy tail. They are ricochetal, moving by hopping in the same manner as kangaroos when startled or frightened, but moving in a quadrupedal fashion at other times. The tail, however, is bushy. The head of a springhaas is short, the eyes are very large, and the ears are enormous, almost as large as a hare's. The pinnae are thinly haired on the posterior surface and hairless on the anterior, also very much like a hare. They have a tragus, which can be folded back to seal the opening of the ear when the animal digs. The forefeet, while much smaller than the hindfeet, are robust and end in 5 long, strongly built, curved and sharp claws. The hindfeet have but 4 toes (note that this is the reverse of most rodents, which have 4 toes on the forefeet and 5 on the hindfeet!); the second toe is much larger than the others, and all end in wide claws that in some ways resemble small hoofs.

The fur of spring hares is long and soft but thin. There is no underfur. The upper parts are usually sandy brown to reddish brown, while the belly is whitish or buffy.

The skull of a springhaas is massive, with very broad frontals and nasals. The arrangement of the masseter appears hystricomorphous; that is, a relatively large medial masseter passes through the greatly enlarged infraorbital foramen as it extends from the side of the rostrum to the lower jaw. A zygomatic plate is present but not large. The jugal is broad. The postorbital process is reduced or absent, and the mastoid region of the basicranium is inflated.

The dental formula of pedetids is 1/1, 0,0, 1/1, 3/3 = 20. The occlusal surface of the cheekteeth is simple, and these teeth are evergrowing.

Springhaas are good diggers, constructing and residing in elaborate burrows. Each burrow system contains a single animal (or pair with young). A number of individuals may dig their burrows close together, however, so that springhaas are sometimes seen out and foraging in groups. They are nocturnal, emerging to feed on bulbs and grasses. They sometimes feed on cultivated crops, including berries, grains, and tubers.

References and literature cited:

Feldhamer, G. A., L. C. Drickamer, S. H. Vessey, and J. F. Merritt. 1999. Mammalogy. Adaptation, Diversity, and Ecology. WCB McGraw-Hill, Boston. xii+563pp.

McLaughlin, C. A. 1984. Protrogomorph, sciuromorph, castorimorph, myomorph (geomyoid, anomaluroid, pedetoid, and ctenodactyloid) rodents. Pp. 267-288 in Anderson, S. and J. K. Jones, Jr. (eds). Orders and Families of Recent Mammals of the World. John Wiley and Sons, N.Y. xii+686 pp.

Paradiso, J. L. 1975. Walker's Mammals of the World, Third Edition. Johns Hopkins University Press, Baltimore.

Savage, R. J. G. and M. R. Long. 1986. Mammal Evolution, an Illustrated Guide. Facts of File Publications, New York. 259 pp.

Vaughan, T. A. 1986. Mammalogy. Third Edition. Saunders College Publishing, Fort Worth. vii+576 pp.

Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mammalogy. Fourth Edition. Saunders College Publishing, Philadelphia. vii+565pp.

Wilson, D. E., and D. M. Reeder. 1993. Mammal Species of the World, A Taxonomic and Geographic Reference. 2nd edition. Smithsonian Institution Press, Washington. xviii+1206 pp.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate