The upper parts are cinnamon, reddish, reddish brown, or brownish, and the underparts are buffy or grayish. The hands and feet are usually white. The tail is usually brownish above and whitish below. A white stripe bordering the lips is present in some individuals. The body form is stocky.
Females have eight mammae.
E. fossor is especially modified externally for a burrowing life in that its fur is soft, its ear conch is greatly reduced, and its claws are elongated. These rodents inhabit brushy and wooded areas. Individuals not quite fully grown have been seen in Patagonia in February, which suggests that breeding may take place near the end of the year. The Johns Hopkins University Press. All rights reserved.