The porcupine is a caviomorph rodent whose ancestors crossed the Atlantic from Africa to Brazil 30 million years ago,[5][6] and then migrated to North America during the Great American Interchange after the Isthmus of Panama rose 3 million years ago.

[9] The porcupine's scientific name, Erethizon dorsatum, can be loosely translated as "the animal with the irritating back".

Erethizon appeared in North America shortly after the two continents joined together in the later Tertiary period.

Some fossils, such as species from the family Paramyidae, show resemblance to the porcupine, but they are so primitive and generalized that they could be ancestors to all later rodents.

[citation needed] South American hystricomorphs first appeared in the Lower Oligocene period.

[12] The earliest purported appearance of E. dorsatum in the fossil record is from the Pleistocene (Irvingtonian) era, found along the Arroyo del Cedazo near Aguascalientes, Mexico.

[1] However, the validity of this fossil's taxonomy is a cause for debate, with some paleontologists arguing that it represents a member of the genus Coendou (the prehensile-tailed porcupines) instead.

[1] The earliest uncontroversial fossils of E. dorsatum, found in the Conard Fissure of Arkansas, date back to the Middle Pleistocene (~130,000 YBP).

Porcupines fall out of trees fairly often because they are highly tempted by the succulent buds and tender twigs at the ends of the branches.

[18] The North American porcupine has a strong odor to warn away predators, which it can increase when agitated.

The odor is generated by a patch of skin called the rosette, on the lower back where modified quills serve as osmetrichia to broadcast the smell.

In eastern North America, porcupines range from Canada to the Appalachian Mountains in West Virginia and Maryland.

They are commonly found in coniferous and mixed forested areas, but have adapted to harsh environments, such as shrublands and tundra.

The strength of the porcupine's defense has given it the ability to live a solitary life, unlike many herbivores, which must move in flocks or herds.

Consequently, the porcupine has "an extraordinary ability to learn complex mazes and to remember them as much as a hundred days afterward".

When threatened, an adult porcupine can bristle its quills, displaying a white stripe down its back, and use its teeth to make a warning, clacking sound.

[citation needed] Natural predators of this species include fishers (a cat-sized mustelid),[21] wolverines,[22] coyotes, wolves,[23] American black bears,[24] and cougars,[25] as well as humans.

[29][30] The North American porcupine is most at risk from the fisher (Pekania pennanti), the male of which may sometimes exceed a mass of 5.5 kg (12 lb).

It can climb trees, so its favorite method is to position itself below the porcupine and knock it to the ground, quickly dispatching it.

The North American porcupine has a long gestation period relative to other rodents, an average of 202 days.

[38] By contrast, the North American beaver, which is comparable in size, has a gestation period of 128 days.

[40] North American porcupines give birth to a single young, referred to as a porcupette.

[41] North American porcupines have a relatively long life expectancy, with some individuals reaching 30 years of age.

[42] Common causes of mortality include predation, starvation, falling out of a tree, and being run over by motor vehicles.

[43] Porcupines are considered by some to be pests because of the damage that they often inflict on trees and wooden and leather objects.

Porcupines are edible and were an important source of food, especially in winter, to the native peoples of Canada's boreal forests.

They have a similar reputation among forestry workers of all types for trying to eat sweat-soaked gloves and wooden handles on tools.