The tail resembles a plume, the hairs increasing in length toward the tip. The hairs on the upper side of the tail, especially those near the apex, have long gray or white tips that produce a hoary effect. On the back of the long ears grow long, stiff hairs that project beyond the ears as conspicuous tufts. The skull differs in shape from that of most squirrels, being broader and flatter. The fronts of the broadened and rounded incisors are longitudinally marked with 7-10 minute grooves.
Forest is the preferred habitat of the groove-toothed squirrel.
Although it had been conjectured that the well-developed tail aids this animal in jumping and climbing about trees, subsequent observations indicated that the squirrel is active mainly on the ground. It is a swift runner and carries the tail bent over the back or held straight out. It has been observed taking refuge among rocks and feeding on fallen fruits. This squirrel sometimes sits upright and practically envelops itself in the bushy tail, with the long ears sticking out on each side. In some areas it reportedly damages gardens.