Biologists and paleontologists have long debated the origins of North American porcupines, with DNA suggesting a 10 million year history, while fossils indicate they may have evolved only 2.5 million years ago. A new study, leveraging a nearly complete porcupine skeleton found in Florida, has clarified this timeline by comparing anatomical differences with South American species, concluding North American porcupines are indeed an ancient group.
Porcupines remained relatively small and evolved adaptations for life in the treetops of South America’s lush rainforests. Today, they travel through the canopy with the aid of long fingers capped with blunt, sickle-shaped claws perfectly angled for gripping branches. Many also have long, prehensile tails capable of bearing their weight, which they use while climbing and reaching for fruit.
Prehistoric elephants, saber-toothed cats, jaguars, llamas, peccaries, deer, skunks, and bears streamed from North America to South. The reverse trek was made by four different kinds of ground sloths, oversized armadillos, terror birds, capybaras, and even a marsupial. They also lost their prehensile tails. Although North American porcupines still like climbing, it’s not their forte. Museum specimens often show evidence of healed bone fractures, likely caused by falling from trees.
By comparing the fossil skeleton with bones from modern porcupines, Bloch and Vitek were confident they could determine its identity. But the amount of work this would require was more than one person could do on their own in a short amount of time. So they co-created a paleontology college course, in which the only assignment for the entire semester was studying porcupine bones.