Genera and Species
They include four genera, of which the first is represented by the North American 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.
The tree porcupines (Coendou, Sphiggurus, and Echinoprocta) contain 16 species. They are found throughout tropical South America, with two 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. These three genera are often united into a single genus Coendou.
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. This animal is often considered a member of the Echimyidae on the basis of its premolar. However, a molecular phylogeny based on the mitochondrial gene coding for cytochrome b combined to karyological evidence actually suggests that the bristle-spined rat is more closely related to the Erethizontidae than to the Echimyidae, and that it is the sister group of all other Erethizontidae.
Read more about this topic: New World Porcupine
Famous quotes containing the words genera and/or species:
“Genius detects through the fly, through the caterpillar, through the grub, through the egg, the constant individual; through countless individuals the fixed species; through many species the genus; through all genera the steadfast type; through all the kingdoms of organized life the eternal unity. Nature is a mutable cloud which is always and never the same.”
—Ralph Waldo Emerson (1803–1882)
“Can it then be doubted, but that God, who is infinitely fine Spirit, and withal intelligent, can make and change all species and kind of body as he pleaseth? But I dare not say, that this is the way by which God Almighty worketh, because it is past my apprehension: yet it serves very well to demonstrate, that the omnipotence of God implieth no contradiction.”
—Thomas Hobbes (1579–1688)