Erethizon dorsatum; Print; The North American porcupine (Erethizon dorsatum); also known as the Canadian porcupine or common porcupine; is a large rodent in the New World porcupine family. The beaver is the only rodent in North America that is larger than the North American porcupine. The porcupine is a caviomorph rodent whose ancestors rafted across the Atlantic from Africa to Brazil over 30 million years ago; and then migrated to North America during the Great American Interchange after the Isthmus of Panama rose 3 million years ago.; 1700-1880