Florida fossil porcupine solves a prickly dilemma 10 million years in the making

There's a longstanding debate simmering among biologists who study porcupines. There are 16 porcupine species in Central and South America, but only one in the United States and Canada. DNA evidence suggests North America's sole porcupine belongs to a group that originated 10 million years ago, but fossils seem to tell a different story. Some paleontologists think they may have evolved just 2.5 million years ago, at the beginning of the ice ages.