Urson
The North American porcupine ("Erethizon dorsatum"), also known as the Canadian porcupine, is a large quill-covered rodent in the New World porcupine family. It is the second largest rodent in North America, after the North American beaver ("Castor canadensis"). The porcupine is a caviomorph rodent whose ancestors crossed the Atlantic from Africa to Brazil 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.