New World porcupine

The New World porcupines are large terrestrial rodents, distinguished by their spiny covering from which they take their name. They are all stout animals, with blunt rounded heads, fleshy mobile snouts, and coats of thick cylindrical or flattened spines ("quills").

The porcupines are represented in the New World by the members of the family Erethizontidae, which have rooted molars, complete collar-bones, entire upper lips, tuberculated soles, no trace of a first front-toe, and four teats. The spines are mixed with long soft hairs.

They are less strictly nocturnal than Old World species in their habits, and with one exception live entirely in trees, having long and powerful prehensile tails.

They include three genera, of which the first is represented by the Canadian Porcupine (Erethizon dorsatum), a stout, heavily built animal, with long hairs almost or quite hiding its spines, four front- and five hind-toes, and a short, stumpy tail. It is a native of the greater part of Canada and the United States, wherever there is any remnant of the original forest left.

Synetheres contains some eight or ten species, known as tree-porcupines, found throughout tropical South America, with one extending into Mexico. They are of a lighter build than the ground-porcupines, with short, close, many-coloured spines, often mixed with hairs, and prehensile tails. The hind-feet have only four toes, owing to the suppression of the first, in place of which they have a fleshy pad on the inner side of the foot; between this pad and the toes, branches and other objects can be firmly grasped as with a hand.

Genus Chaetomys, distinguished by the shape of its skull and the greater complexity of its teeth, contains C. subspinosus, a native of the hottest parts of Brazil.