Classification of a porcupine
 The common name of this mammal is porcupine. Porcupines come from the kingdom animalia, or animals; the phylum chordata, chordates; and the class rodentia, or rodents. But porcupines can either be in two families, the hystricidae: old world porcupines, or the erethizontidae: new world porcupines. These two families however belong to the hystricognathi branch of the order rodentia, but the families are not the same at all. There are eleven old world porcupines and are believed to have separated from the branch about 30 million years ago. The twelve new world porcupines are smaller  and are more closely related to other families of rodents than the old world porcupines.


Porcupine eating tree bark
 Porcupines are herbivores, and are nocturnal, so they forage at night. Depending on where they live, porcupines eat different kinds of plants. They eat raspberry stems, grasses, flowering herbs, and big amounts of apples. Also, they feed on nuts and acorns since they are good at getting these nuts out of trees. Being a herbivore affects the sodium metabolism of porcupines, so they crave salt too. As a result, they will chew on wooden handles of human tools, wood structures, and areas of collected roadside salt runoff.        
             To help them chew, porcupines have special adaptions. They do not have canine teeth, allowing them to draw in their lips while gnawing. In addition to this, they have a speciall arrangement of their jaw muscles, helping them to chew more effectively. Since porcupines have good grip, porcupines can stay in trees using only their hind feet, freeing up their forelimbs to eat.

Physical Traits and Behavior

A group of porcupines eating food.
  There are many kinds of porcupines in the world and 21 species to be exact. All porcupines have a snout, slow, heavy form and a spiny coat. Most of them appear to be dark brown to black, however some of the hairs and quills on the backs of porcupines are yellow.  They have long claws to help them climb on tree trunks and also small branches. On their palms and soles, porcupines have a pebbly surface with no fur. This helps the grip of the porcupine so they can stay in trees using only their hind feet to stay on. Porcupines are the third largest rodents, after the capybara and beaver. Many porcupines weigh about 12-35 pounds and are about 25-35 inches long with a 8-10 in long tail. Their spiny protection is like that of hedgehogs and echidnas. Quills are made of modified hairs with a coat of keratin. Porcupines are endothermic, meaning they are able to make their own body heat, allowing them to withstand cold temperatures.
            Porcupines are not very social, spending most of their time alone. But in the winter, they are more social, when they may share dens with other porcupines and search for food in groups. Since they have great defenses, porcupines do not need to live in groups to defend themselves from predators. Both male and female porcupines are territorial, although males defend their territory more than females do. A single porcupine knows it territory very well and usually doesn't go to far from it, except for going to get salt or other foods.